title: Collatz conjecture

text: Alternatively, replace the with where and is the highest power of 2 that divides (with no remainder). The resulting function maps from odd numbers to odd numbers. Now suppose that for some odd number , applying this operation times yields the number 1 (that is, ). Then in binary, the number can be written as the concatenation of strings where each is a finite and contiguous extract from the representation of . The representation of therefore holds the repetends of , where each repetend is optionally rotated and then replicated up to a finite number of bits. It is only in binary that this occurs. Conjecturally, every binary string that ends with a '1' can be reached by a representation of this form (where we may add or delete leading '0's to ).


title: Collatz conjecture

text: Repeated applications of the Collatz function can be represented as an abstract machine that handles strings of bits. The machine will perform the following three steps on any odd number until only one remains:


title: Collatz conjecture

text: If is the parity of a number, that is and , then we can define the Collatz parity sequence (or parity vector) for a number as , where , and .


title: Collatz conjecture

text: Which operation is performed, or , depends on the parity. The parity sequence is the same as the sequence of operations.


title: Collatz conjecture

text: Using this form for , it can be shown that the parity sequences for two numbers and will agree in the first terms if and only if and are equivalent modulo . This implies that every number is uniquely identified by its parity sequence, and moreover that if there are multiple Hailstone cycles, then their corresponding parity cycles must be different.


title: Collatz conjecture

text: Applying the function times to the number will give the result , where is the result of applying the function times to , and is how many increases were encountered during that sequence. For example, for there are 3 increases as 1 iterates to 2, 1, 2, 1, and finally to 2 so the result is ; for there is only 1 increase as 1 rises to 2 and falls to 1 so the result is . When is then there will be rises and the result will be . The factor of 3 multiplying is independent of the value of ; it depends only on the behavior of . This allows one to predict that certain forms of numbers will always lead to a smaller number after a certain number of iterations: for example, becomes after two applications of and becomes after 4 applications of . Whether those smaller numbers continue to 1, however, depends on the value of .


title: Collatz conjecture

text: In this system, the positive integer is represented by a string of copies of , and iteration of the tag operation halts on any word of length less than 2. (Adapted from De Mol.)


title: Collatz conjecture

text: The Collatz conjecture equivalently states that this tag system, with an arbitrary finite string of as the initial word, eventually halts (see "" for a worked example).


title: Collatz conjecture

text: An extension to the Collatz conjecture is to include all integers, not just positive integers. Leaving aside the cycle 0 → 0 which cannot be entered from outside, there are a total of four known cycles, which all nonzero integers seem to eventually fall into under iteration of . These cycles are listed here, starting with the well-known cycle for positive :


title: Collatz conjecture

text: Odd values are listed in large bold. Each cycle is listed with its member of least absolute value (which is always odd) first.


title: Collatz conjecture

text: The generalized Collatz conjecture is the assertion that every integer, under iteration by , eventually falls into one of the four cycles above or the cycle 0 → 0. (The 0 → 0 cycle is only included for the sake of completeness.)


title: Collatz conjecture

text: The Collatz map can be extended to (positive or negative) rational numbers which have odd denominators when written in lowest terms.


title: Collatz conjecture

text: The number is taken to be 'odd' or 'even' according to whether its numerator is odd or even. Then the formula for the map is exactly the same as when the domain is the integers: an 'even' such rational is divided by 2; an 'odd' such rational is multiplied by 3 and then 1 is added. A closely related fact is that the Collatz map extends to the ring of 2-adic integers, which contains the ring of rationals with odd denominators as a subring.


title: Collatz conjecture

text: When using the "shortcut" definition of the Collatz map, it is known that any periodic parity sequence is generated by exactly one rational. Conversely, it is conjectured that every rational with an odd denominator has an eventually cyclic parity sequence (Periodicity Conjecture).


title: Collatz conjecture

text: If a parity cycle has length and includes odd numbers exactly times at indices , then the unique rational which generates immediately and periodically this parity cycle is


title: Collatz conjecture

text: For example, the parity cycle has length 7 and four odd terms at indices 0, 2, 3, and 6. It is repeatedly generated by the fraction


title: Collatz conjecture

text: Any cyclic permutation of is associated to one of the above fractions. For instance, the cycle is produced by the fraction


title: Collatz conjecture

text: For a one-to-one correspondence, a parity cycle should be "irreducible", that is, not partitionable into identical sub-cycles. As an illustration of this, the parity cycle and its sub-cycle are associated to the same fraction when reduced to lowest terms.


title: Collatz conjecture

text: In this context, assuming the validity of the Collatz conjecture implies that and are the only parity cycles generated by positive whole numbers (1 and 2, respectively).


title: Collatz conjecture

text: If the odd denominator of a rational is not a multiple of 3, then all the iterates have the same denominator and the sequence of numerators can be obtained by applying the " " generalization of the Collatz function


title: Collatz conjecture

text: is well-defined on the ring formula_15 of 2-adic integers, where it is continuous and measure-preserving with respect to the 2-adic measure. Moreover, its dynamics is known to be ergodic.


title: Collatz conjecture

text: The function is a 2-adic isometry. Consequently, every infinite parity sequence occurs for exactly one 2-adic integer, so that almost all trajectories are acyclic in formula_15.


title: Collatz conjecture

text: The iterations of this map on the real line lead to a dynamical system, further investigated by Chamberland.


title: Collatz conjecture

text: He showed that the conjecture does not hold for positive real numbers since there are infinitely many fixed points, as well as orbits escaping monotonically to infinity. The function has two attracting cycles of period 2, and . Moreover, the set of unbounded orbits is conjectured to be of measure 0.


title: Collatz conjecture

text: Letherman, Schleicher, and Wood extended the study to the complex plane, where most of the points have orbits that diverge to infinity (colored region on the illustration). The boundary between the colored region and the black components, namely the Julia set of , is a fractal pattern, sometimes called the "Collatz fractal".


title: Collatz conjecture

text: The section "As a parity sequence" above gives a way to speed up simulation of the sequence. To jump ahead steps on each iteration (using the function from that section), break up the current number into two parts, (the least significant bits, interpreted as an integer), and (the rest of the bits as an integer). The result of jumping ahead steps can be found as:


title: Collatz conjecture

text: The (or better ) and arrays are precalculated for all possible -bit numbers , where is the result of applying the function times to , and is the number of odd numbers encountered on the way. For example, if , one can jump ahead 5 steps on each iteration by separating out the 5 least significant bits of a number and using:


title: Collatz conjecture

text: This requires precomputation and storage to speed up the resulting calculation by a factor of , a space–time tradeoff.


title: Collatz conjecture

text: For the special purpose of searching for a counterexample to the Collatz conjecture, this precomputation leads to an even more important acceleration, used by Tomás Oliveira e Silva in his computational confirmations of the Collatz conjecture up to large values of . If, for some given and , the inequality


title: Collatz conjecture

text: holds for all , then the first counterexample, if it exists, cannot be modulo . For instance, the first counterexample must be odd because , smaller than ; and it must be 3 mod 4 because , smaller than . For each starting value which is not a counterexample to the Collatz conjecture, there is a for which such an inequality holds, so checking the Collatz conjecture for one starting value is as good as checking an entire congruence class. As increases, the search only needs to check those residues that are not eliminated by lower values of . Only an exponentially small fraction of the residues survive. For example, the only surviving residues mod 32 are 7, 15, 27, and 31.


title: Collatz conjecture

text: If is an odd integer, then is even, so with odd and . The Syracuse function is the function from the set of odd integers into itself, for which .


title: Collatz conjecture

text: The Collatz conjecture is equivalent to the statement that, for all in , there exists an integer such that .


title: Collatz conjecture

text: In 1972, John Horton Conway proved that a natural generalization of the Collatz problem is algorithmically undecidable.


title: Collatz conjecture

text: Modifying the condition in this way can make a problem either harder or easier to solve (intuitively, it is harder to justify a positive answer but might be easier to justify a negative one). Kurtz and Simon proved that the above problem is, in fact, undecidable and even higher in the arithmetical hierarchy, specifically -complete. This hardness result holds even if one restricts the class of functions by fixing the modulus to 6480.


title: Collatz conjecture

text: In the movie "Incendies", a graduate student in pure mathematics explains the Collatz conjecture to a group of undergraduates. She puts her studies on hold for a time to address some unresolved questions about her family's past. Late in the movie, the Collatz conjecture turns out to have foreshadowed a disturbing and difficult discovery that she makes about her family.


title: William James Sidis

text: William James Sidis (; April 1, 1898 – July 17, 1944) was an American child prodigy with exceptional mathematical and linguistic skills. He is notable for his 1920 book "The Animate and the Inanimate", in which he speculates about the origin of life in the context of thermodynamics.


title: William James Sidis

text: Sidis was raised in a particular manner by his father, psychiatrist Boris Sidis, who wished his son to be gifted. Sidis first became famous for his precocity and later for his eccentricity and withdrawal from public life. Eventually, he avoided mathematics altogether, writing on other subjects under a number of pseudonyms. He entered Harvard at age 11 and, as an adult, was said to have an extremely high IQ, and to be conversant in about 25 languages and dialects. Some of these statements have not been verified, but many of his contemporaries, including Norbert Wiener, Daniel Frost Comstock and William James, agreed that he was extremely intelligent.


title: William James Sidis

text: Sidis was born to Jewish emigrants from Ukraine, on April 1, 1898, in New York City. His father, Boris Sidis, had emigrated in 1887 to escape political and anti-semitic persecution. His mother, Sarah (Mandelbaum) Sidis, and her family had fled the pogroms in the late 1880s. Sarah attended Boston University and graduated from its School of Medicine in 1897. William was named after his godfather, Boris's friend and colleague, the American philosopher William James. Boris was a psychiatrist and published numerous books and articles, performing pioneering work in abnormal psychology. He was a polyglot, and his son William would also become one at a young age.


title: William James Sidis

text: Sidis's parents believed in nurturing a precocious and fearless love of knowledge, although their methods of parenting were criticized in the media and retrospectively. Sidis could read The New York Times at 18 months. By age eight, he had reportedly taught himself eight languages (Latin, Greek, French, Russian, German, Hebrew, Turkish, and Armenian) and invented another, which he called "Vendergood".


title: William James Sidis

text: Although the University had previously refused to let his father enroll him at age 9 because he was still a child, Sidis set a record in 1909 by becoming the youngest person to enroll at Harvard University. In early 1910, Sidis's mastery of higher mathematics was such that he lectured the Harvard Mathematical Club on four-dimensional bodies, attracting nationwide attention. Notable child prodigy, cybernetics pioneer Norbert Wiener, who also attended Harvard at the time and knew Sidis, later stated in his book "Ex-Prodigy": "The talk would have done credit to a first or second-year graduate student of any age...talk represented the triumph of the unaided efforts of a very brilliant child." MIT physics professor Daniel F. Comstock was full of praises: "Karl Friedrich Gauss is the only example in history, of all prodigies, whom Sidis resembles. I predict that young Sidis will be a great astronomical mathematician. He will evolve new theories and invent new ways of calculating astronomical phenomena. I believe he will be a great mathematician, the leader in that science in the future." Sidis began taking a full-time course load in 1910 and earned his Bachelor of Arts degree, "cum laude", on June 18, 1914, at age 16.


title: William James Sidis

text: Shortly after graduation, he told reporters "I want to live the perfect life. The only way to live the perfect life is to live it in seclusion". He granted an interview to a reporter from the "Boston Herald". The paper reported Sidis's vows to remain celibate and never to marry, as he said women did not appeal to him. Later he developed a strong affection for Martha Foley, one year older than him. He later enrolled at Harvard Graduate School of Arts and Sciences.


title: William James Sidis

text: After a group of Harvard students threatened Sidis physically, his parents secured him a job at the William Marsh Rice Institute for the Advancement of Letters, Science, and Art (now Rice University) in Houston, Texas, as a mathematics teaching assistant. He arrived at Rice in December 1915 at the age of 17. He was a graduate fellow working toward his doctorate.


title: William James Sidis

text: Sidis taught three classes: Euclidean geometry, non-Euclidean geometry, and freshman math (he wrote a textbook for the Euclidean geometry course in Greek). After less than a year, frustrated with the department, his teaching requirements, and his treatment by students older than himself, Sidis left his post and returned to New England. When a friend later asked him why he had left, he replied, "I never knew why they gave me the job in the first place—I'm not much of a teacher. I didn't leave: I was asked to go." Sidis abandoned his pursuit of a graduate degree in mathematics and enrolled at the Harvard Law School in September 1916, but withdrew in good standing in his final year in March 1919.


title: William James Sidis

text: In 1919, shortly after his withdrawal from law school, Sidis was arrested for participating in a socialist May Day parade in Boston that turned violent. He was sentenced to 18 months in prison under the Sedition Act of 1918 by Roxbury Municipal Court Judge Albert F Hayden. Sidis's arrest featured prominently in newspapers, as his early graduation from Harvard had garnered considerable local celebrity status. During the trial, Sidis stated that he had been a conscientious objector to the World War I draft, was a socialist, and did not believe in a god like the "big boss of the Christians," but rather in something that is in a way apart from a human being. He later developed his own libertarian philosophy based on individual rights and "the American social continuity". His father arranged with the district attorney to keep Sidis out of prison before his appeal came to trial; his parents, instead, held him in their sanatorium in New Hampshire for a year. They took him to California, where he spent another year. At the sanatorium, his parents set about "reforming" him and threatened him with transfer to an insane asylum.


title: William James Sidis

text: After returning to the East Coast in 1921, Sidis was determined to live an independent and private life. He only took work running adding machines or other fairly menial tasks. He worked in New York City and became estranged from his parents. It took years before he was cleared legally to return to Massachusetts, and he was concerned for years about his risk of arrest. He obsessively collected streetcar transfers, wrote self-published periodicals, and taught small circles of interested friends his version of American history. In 1933, Sidis passed a Civil Service exam in New York, but scored a low ranking of 254. In a private letter, Sidis wrote that this was "not so encouraging". In 1935, he wrote an unpublished manuscript, "The Tribes and the States", which traces Native American contributions to American democracy.


title: William James Sidis

text: In 1944, Sidis won a settlement from "The New Yorker" for an article published in 1937. He had alleged it contained many false statements. Under the title "Where Are They Now?", James Thurber pseudonymously described Sidis's life as lonely, in a "hall bedroom in Boston's shabby South End". Lower courts had dismissed Sidis as a public figure with no right to challenge personal publicity. He lost an appeal of an invasion of privacy lawsuit at the United States Court of Appeals for the Second Circuit in 1940 over the same article. Judge Charles Edward Clark expressed sympathy for Sidis, who claimed that the publication had exposed him to "public scorn, ridicule, and contempt" and caused him "grievous mental anguish [and] humiliation," but found that the court was not disposed to "afford to all the intimate details of private life an absolute immunity from the prying of the press".


title: William James Sidis

text: From writings on cosmology, to writings on Native American history, to "Notes on the Collection of Transfers," and several purported lost texts on anthropology, philology, and transportation systems, Sidis covered a broad range of subjects. Some of his ideas concerned cosmological reversibility and "social continuity".


title: William James Sidis

text: In "The Animate and the Inanimate" (1925), Sidis predicted the existence of regions of space where the second law of thermodynamics operated in reverse to the temporal direction that we experience in our local area. Everything outside of what we would today call a galaxy would be such a region. Sidis said that the matter in this region would not generate light. Sidis's "The Tribes and the States" (c. 1935) employs the pseudonym "John W. Shattuck", purporting to give a 100,000-year history of the Settlement of the Americas, from prehistoric times to 1828. In this text, he suggests that "there were red men at one time in Europe as well as in America".


title: William James Sidis

text: Sidis was also a "peridromophile", a term he coined for people fascinated with transportation research and streetcar systems. He wrote a treatise on streetcar transfers under the pseudonym of "Frank Folupa" that identified means of increasing public transport usage.


title: William James Sidis

text: Sidis wrote The Animate and the Inanimate to detail his thoughts on the origins of life, cosmology, and the potential reversibility of the second law of thermodynamics through Maxwell's Demon, among other things. It was published in 1925; however, it has been suggested that Sidis was working on the theory as early as 1916. One motivation for writing this theory appears to be to explain psychologist and philosopher William James's "reserve energy" theory which said that there was "reserve energy" that could be used by people when put under extreme conditions, Sidis's own "forced prodigy" upbringing being a result of testing said theory. The work is one of the few works that Sidis did not write under a pseudonym.


title: William James Sidis

text: In "The Animate and the Inanimate", Sidis states that the universe is infinite, as well as it containing sections of "negative tendencies" where various laws of physics were reversed that are juxtaposed with "positive tendencies", which switch over epochs of time. Sidis states that there was not an "origin of life", but that life has always existed and that it has only changed through evolution. Sidis also adopts Eduard Pflüger's cyanogen based life theory, and Sidis cites "organic" things such as almonds (his example) that have cyanogen that doesn't kill, as cyanogen (and derivatives thereof) is normally a highly toxic substance thus making this a strange anomaly. Sidis describes his theory as a fusion of the mechanistic model of life and the vitalist model of life, as well as entertaining the notion of life coming to earth from asteroids (as advanced by Lord Kelvin and Hermann von Helmholtz). Sidis also states that functionally speaking, stars are "alive" and undergo an eternally repeating light-dark cycle, reversing the second law in the dark portion of the cycle.


title: William James Sidis

text: Sidis's theory at the time of its release was ignored, only to be found in an attic in 1979. Upon this discovery, Buckminster Fuller (who was a classmate of William James Sidis) said the following about "The Animate and the Inanimate":


title: William James Sidis

text: Sidis created a constructed language called Vendergood in his second book, the "Book of Vendergood", which he wrote at the age of 8. The language was mostly based on Latin and Greek, but also drew on German and French and other Romance languages. It distinguished between eight moods: indicative, potential, imperative absolute, subjunctive, imperative, infinitive, optative, and Sidis's own . One of its chapters is titled "Imperfect and Future Indicative Active". Other parts explain the origin of Roman numerals. It uses base 12 instead of base 10:


title: William James Sidis

text: The Tribes and the States outlines the history of the Native Americans, focusing mostly on the Northeastern tribes and continuing up to the mid-19th century. It was written around 1935 but was never published for lack of completion at the time of Sidis's death. Sidis wrote the history under the pseudonym "John W. Shattuck". Much of the history was taken from wampum belts; Sidis explained, "The weaving of wampum belts is a sort of writing by means of belts of colored beads, in which the various designs of beads denoted different ideas according to a definitely accepted system, which could be read by anyone acquainted with wampum language, irrespective of what the spoken language is. Records and treaties are kept in this manner, and individuals could write letters to one another in this way."


title: William James Sidis

text: Much of the subject matter of the book is centered on the influence of Native Americans on migrating Europeans and the effect of Native Americans on the formation of the United States. It describes the origination of the federations that were to be an important event to the Founding Fathers.


title: William James Sidis

text: After his death, Helena Sidis said that her brother had an IQ reported in Abraham Sperling's 1946 book "Psychology for the Millions" as "the very highest that had ever been obtained", but later authors found that some of his biographers, such as Amy Wallace, exaggerated how high his IQ actually was. Sperling actually wrote:


title: William James Sidis

text: It has been acknowledged that Helena and William's mother Sarah had developed a reputation of exaggerated statements about the Sidis family. Helena had also falsely stated that the Civil Service exam William took in 1933 was an IQ test and that his ranking of 254 was instead an IQ score of 254. It is speculated that the number "254" was actually William's placement on the list after he passed the Civil Service exam, as he stated in a letter sent to his family. Helena also said that "Billy knew all the languages in the world, while my father only knew 27. I wonder if there were any Billy didn't know." This statement was not backed by any other source outside the Sidis family, and Sarah Sidis also made an improbable statement in her 1950 book "The Sidis Story" that William could learn a language in just one day. Boris Sidis had once dismissed tests of intelligence as "silly, pedantic, absurd, and grossly misleading". Regardless of the exaggerations, Sidis was judged by contemporaries such as MIT Physics professor Daniel Frost Comstock and American mathematician Norbert Wiener (who wrote about Sidis in his autobiography) to have had real ability.


title: William James Sidis

text: Sidis's life and work, particularly his ideas about Native Americans, are extensively discussed in Robert M. Pirsig's book "" (1991). Sidis is also discussed in "Ex-Prodigy", an autobiography by mathematician Norbert Wiener (1894–1964), who was a prodigy himself.


title: William James Sidis

text: The Danish author wrote a novel as a fictional account based on Sidis's life; "The Perfect Life of William Sidis" was published in Denmark in 2011. Another novel based on his biography was published by the German author in 2017.


title: William James Sidis

text: The debate about Sidis's manner of upbringing occurred within a larger discourse about the best way to educate children. Newspapers criticized Boris Sidis's child-rearing methods. Most educators of the day believed that schools should expose children to common experiences to create good citizens. Most psychologists thought intelligence was hereditary, a position that precluded early childhood education at home.


title: William James Sidis

text: The difficulties Sidis encountered in dealing with the social structure of a collegiate setting may have shaped opinion against allowing such children to rapidly advance through higher education in his day. Research indicates that a challenging curriculum can relieve social and emotional difficulties commonly experienced by gifted children. Embracing these findings, several colleges now have procedures for early entrance. The Davidson Institute for Talent Development has developed a guidebook on the topic.


title: William James Sidis

text: Sidis was portrayed derisively in the press of the day. "The New York Times", for example, described him as "a wonderfully successful result of a scientific forcing experiment". His mother later maintained that newspaper accounts of her son bore little resemblance to him.


title: Markie Post

text: Marjorie Armstrong "Markie" Post (November 4, 1950 – August 7, 2021) was an American actress. She is known for her roles as bail bondswoman Terri Michaels in "The Fall Guy" on ABC from 1982 to 1985, as public defender Christine Sullivan on the NBC sitcom "Night Court" from 1985 to 1992, as Georgie Anne Lahti Hartman on the CBS sitcom "Hearts Afire" from 1992 to 1995, and as Barbara ‘Bunny’ Fletcher, mother of Sophia Bush’s character, Detective Erin Lindsay, from 2014 to 2017 in 18 episodes of "Chicago P.D." across seasons 2-4.


title: Markie Post

text: Post was born in Palo Alto, California, on November 4, 1950. Her father, Richard F. Post, worked as a physicist; her mother, Marylee (Armstrong) Post, was a poet. The second of the couple's three children, her two siblings and she were raised in Stanford and Walnut Creek. She attended Las Lomas High School and was a cheerleader. She went to Lewis & Clark College in Portland, Oregon, and briefly Pomona College in California, before returning to earn her bachelor of arts degree from Lewis & Clark.


title: Markie Post

text: Prior to acting, Post worked on several game shows. She began her career with the production crew of the Tom Kennedy version of "Split Second". She also served as associate producer of CBS's "Double Dare" and as a card dealer on NBC's "Card Sharks". Later, after achieving fame as an actress, she played various game shows as a celebrity guest, including "The" "Match Game-Hollywood Squares Hour", "Super Password", "The (New) $25,000 Pyramid", and "The $100,000 Pyramid". She helped a contestant win the $100,000 grand prize in a November 1987 tournament episode of "The $100,000 Pyramid".


title: Markie Post

text: Post's early acting credits included a 1979 episode of "Barnaby Jones" and the pilot episode of "Simon & Simon" "Details at Eleven" in 1981, episode one of season two of "The Greatest American Hero", two episodes of "The A-Team" as two different characters in the 1983 episode "The Only Church in Town" and the 1984 episode "Hot Styles", and "The Love Boat". She appeared in the science-fiction series "Buck Rogers in the 25th Century" and as Diane Chambers' best friend in the sitcom "Cheers", before eventually becoming a regular on the ABC action drama "The Fall Guy". After "The Fall Guy", she played Christine Sullivan on the 1980s television comedy series "Night Court" from the third season until the show's end. She played Georgie Anne Lahti Hartman on the comedy series "Hearts Afire", co-starring John Ritter. Post also had regularly recurring guest-star roles on "The District" and on "Scrubs" as the mother of Dr. Elliot Reid.


title: Markie Post

text: Her film credits include "There's Something About Mary" (1998), in which Post played Mary's mother. She played a call girl and dominatrix in the 1988 TV movie "Tricks of the Trade" opposite Cindy Williams, and a singer in "Glitz" with Jimmy Smits, based on the novel by Elmore Leonard. She also had a starring role in NBC's 1995 movie "Visitors in the Night". She appeared as reporter Christine Merriweather in the 2007 improvisational comedy film (released in 2017) "Cook Off!". She appeared in the "30 Rock" episode "The One with the Cast of Night Court" playing herself when Harry Anderson, Charles Robinson, and she staged a mock reunion of the "Night Court" cast.


title: Markie Post

text: Post was the voice of June Darby on the computer-animated robot superhero TV series "". She appeared as recurring character Barbara 'Bunny' Fletcher in the first four seasons of "Chicago P.D."


title: Markie Post

text: Post was married first to Stephen Knox, whom she met at Lewis & Clark College. She later married actor and writer Michael A. Ross, with whom she had two daughters.


title: Markie Post

text: Post died at her home in Los Angeles on August 7, 2021, aged 70, after battling cancer for almost four years.


title: 6.5mm Creedmoor

text: The 6.5mm Creedmoor (6.5×48 mm), designated 6.5 Creedmoor by SAAMI, 6.5 Creedmoor by the C.I.P. or 6.5 CM or 6.5 CRDMR for short, is a centerfire rifle cartridge introduced by Hornady in 2007. It was developed by Hornady senior ballistics scientist Dave Emary in partnership with Dennis DeMille, the vice-president of product development at Creedmoor Sports, hence the name. The cartridge is a necked-down modification of the .30 Thompson Center.


title: 6.5mm Creedmoor

text: The 6.5mm Creedmoor was designed specifically for long-range target shooting, although it has been used successfully in game hunting. Bullet-for-bullet, the 6.5mm Creedmoor achieves a slower muzzle velocity than longer cartridges such as the 6.5-284 Norma or magnum cartridges such as the 6.5mm Remington Magnum. However, due to its overall length of , it is capable of chambering in short-action rifles like the 6.5×47mm Lapua.


title: 6.5mm Creedmoor

text: In general, 6.5 mm (.264 in) bullets are known for their high sectional density and ballistic coefficients, and often have been used successfully in rifle competitions.


title: 6.5mm Creedmoor

text: The 6.5mm Creedmoor was designed for target shooting at longer ranges, and as such, couples a sensible case volume (3.40 ml) to bore area (34.66 mm/0.3466 cm) ratio with ample space for loading long slender projectiles providing good aerodynamic efficiency and external ballistic performance for the projectile diameter.


title: 6.5mm Creedmoor

text: For some loads, the 6.5mm Creedmoor is capable of duplicating the muzzle velocity or trajectory of the .300 Winchester Magnum while generating significantly-lower recoil, based on lighter projectile weight.


title: 6.5mm Creedmoor

text: Americans define the shoulder angle at alpha/2 = 30 degrees. The common rifling twist rate for this cartridge is 203 mm (1 in 8 in), 6 grooves, Ø lands = , Ø grooves = , land width = , and the primer type is large rifle or small rifle depending on the cartridge case manufacturer.


title: 6.5mm Creedmoor

text: According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings, 6.5mm Creedmoor can handle up to P piezo pressure. In C.I.P. regulated countries, every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.


title: 6.5mm Creedmoor

text: The 6.5mm Creedmoor is a medium-power cartridge comparable to the .260 Remington and 6.5×47mm Lapua. Its energy at 300 yards using 129-grain Hornady SST bullets is listed by an independent reviewer as . For the 140-grain bullet at initial velocity, another reviewer reports an MPBR for a six-inch-high target of , and reports a manufacturer-claim of "almost " of retained energy at using a barrel. SAAMI test data confirms 6.5 mm Creedmoor, from muzzle, velocity of for the 129-grain bullet and for the 140-grain bullet (which compares to .300 Winchester Magnum data of for a 200-grain bullet and for a 210-grain bullet).


title: 6.5mm Creedmoor

text: The cartridge stays supersonic and maintains its accuracy to past , while the .308 Winchester with 168-grain match bullets has a supersonic range of about .


title: 6.5mm Creedmoor

text: A semiautomatic sniper rifle with a 20-inch barrel, in 6.5mm Creedmoor, is capable of engaging military targets from point blank range to 1,100 meters.


title: 6.5mm Creedmoor

text: Handloading costs for the 6.5mm Creedmoor are roughly-equivalent to other 6.5 mm cartridges, such as the 6.5×47mm Lapua, due to the availability of Lapua small primer brass for both cartridges. As of January 2020 Lapua is also manufacturing 6.5 Creedmoor brass with large rifle primers. Norma makes brass for the cartridge, and Norma brass is available through several major-retailers at approximately the same cost as Lapua brass. Lapua brass for 6.5×47 lasts for about 12-to-20 reloads. Starline sells brass cases with either large or small primer pockets, with small pocket brass costing slightly more.


title: 6.5mm Creedmoor

text: After the 6.5mm Creedmoor was introduced, it was advertised as a 60,000 psi capable case. However, after it was placed into production, Hornady listed it as 62,000 psi, then registered it with SAAMI as such. For this reason, many hand loaders have poor experiences reloading for it. Blown primers on the first shot at 62,000 psi are not uncommon. Early shooting articles listed the ammo as loaded to 58,000 psi, but later citings list it as 57,000 psi. Hornady reduced the loads in its factory ammo because of complaints it was often blowing primers.


title: 6.5mm Creedmoor

text: Lapua delivered 6.5mm Creedmoor brass at Shot show 2017, and production quantities became available via major retailers in second quarter 2017. The Lapua version has a small primer pocket. Thus, load data for small-primer brass are not interchangeable with those for large-primer brass. A smaller diameter decapping rod is required to size and decap. As of January 2020 Lapua also manufactures its brass with large rifle primers addressing concerns that some small rifle primers may not efficiently ignite the powder charge in cold weather conditions causing hang fires or misfires. Large rifle primer Lapua brass also allows the use of a standard size decapping rod.


title: 6.5mm Creedmoor

text: The 6mm Creedmoor is a necked-down version of the 6.5mm Creedmoor using 6 mm (.243 inch) bullets, lighter than 6.5 mm bullets with similarly-reduced recoil. John Snow at "Outdoor Life" built a 6mm Creedmoor rifle in 2009 for a magazine article of the wildcat cartridge that appeared in 2010, but the first documented conception of the 6mm Creedmoor was by Lee Gardner, a Snipershide forum user in May 2009. As of May 2018, Savage Arms offers three bolt-action rifles and one semiautomatic rifle chambered in 6mm Creedmoor. As of May 2018, Hornady offers 87-gr Varmint Express, 103-gr Precision Hunter and 108-gr Match ammunition in 6mm Creedmoor. Performance-wise, the 6mm Creedmoor is nearly identical to .243 Winchester, with slightly less powder room but often loaded to slightly higher pressures. However since the cartridge was designed from the outset to better handle longer bullets and rifles are accordingly built with fast twist rates the 6mm Creedmoor will usually give better performance with heavy for caliber bullets than the .243.


title: 6.5mm Creedmoor

text: The .22 Creedmoor is another even further necked-down version of the 6.5mm Creedmoor using .22 (.224 inch) bullets, lighter than 6 mm bullets with even softer recoil.


title: 6.5mm Creedmoor

text: In October 2017, U.S. Special Operations Command (USSOCOM) tested the performance of 7.62×51mm NATO (M118LR long-range 7.62×51mm NATO load), .260 Remington, and 6.5mm Creedmoor cartridges out of SR-25, M110A1, and Mk 20 Sniper Support Rifle (SSR) rifles. SOCOM determined 6.5 Creedmoor performed the best, doubling hit-probability at , increasing effective range by nearly half, reducing wind drift by a third, with less recoil than 7.62×51mm NATO rounds. Tests showed the .260 Remington and 6.5mm Creedmoor cartridges were similarly accurate and reliable, and the external ballistic behavior was also very-similar. The prevailing attitude is there was more room with the 6.5mm Creedmoor to develop projectiles and loads.


title: 6.5mm Creedmoor

text: As the two cartridges (7.62×51mm NATO and 6.5 mm Creedmoor) have similar dimensions, the same magazines can be used, and a rifle can be converted with just a barrel change. This led to its adoption and fielding by special operations snipers to replace the 7.62×51mm NATO cartridge in their semi-automatic sniper rifles, planned in early 2019. In response to SOCOM's adoption, Department of Homeland Security also decided to adopt the round. U.S. Special Operations Command will convert their 7.62×51mm NATO M110 Semi-automatic Sniper rifle (SASS) and Mk 20 Sniper Support Rifle (SSR) rifles to 6.5 Creedmoor in 2019, a process that requires just a new barrel. In 2018, USSOCOM announced they would roll-out 6.5 mm Creedmoor in a long-range precision rifle, and use it in a carbine and assault machine-gun. The US Special Operations Forces will use the same caliber for an assault rifle, light machine gun, and sniper rifle. That will give better penetration and terminal ballistics (because of high sectional density and retained energy) while providing longer range precision fire.


title: 6.5mm Creedmoor

text: At the National Defense Industry Association’s annual Special Operations Forces Industry Conference (SOFIC), beginning May 20, 2019, FN unveiled a prototype of its Mk 48 Mod 2 machine gun chambered in 6.5 mm Creedmoor to fill a USSOCOM requirement. American special operations forces are in the process of acquiring a lightweight belt-fed machine gun offering a better range than existing weapons. 6.5 Creedmoor has since received the designation of XM1200.


title: 6.5mm Creedmoor

text: In November 2019, the U.S. Navy ordered 6.5mm Creedmoor conversion kits to upgrade the M110 Semi-Automatic Sniper System to the M110K1 variant.


title: 6.5mm Creedmoor

text: In April 2020 the United States Department of Defense decided to replace the Mk13 .300 Winchester Magnum sniper rifle with a barrel, semi-automatic AR-10 platform chambered in 6.5 mm Creedmoor and ammunition for engagements from .


title: Sea urchin

text: Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of sea urchins are round and spiny, ranging in diameter from . Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines. Although algae are the primary diet, sea urchins also eat slow-moving (sessile) animals. Predators that eat sea urchins include a wide variety of fish, starfish, crabs, marine mammals. Sea urchins are also used as food especially in Japan.


title: Sea urchin

text: Adult sea urchins have fivefold symmetry, but their pluteus larvae feature bilateral (mirror) symmetry, indicating that the sea urchin belongs to the Bilateria group of animal phyla, which also comprises the chordates and the arthropods, the annelids and the molluscs, and are found in every ocean and in every climate, from the tropics to the polar regions, and inhabit marine benthic (sea bed) habitats, from rocky shores to hadal zone depths. The fossil record of the "Echinoids" dates from the Ordovician period, some 450 million years ago. The closest echinoderm relatives of the sea urchin are the sea cucumbers (Holothuroidea), both of which are deuterostomes, a clade that includes the chordates.


title: Sea urchin

text: The animals have been studied since the 19th century as model organisms in developmental biology, as their embryos were easy to observe. That has continued with studies of their genomes because of their unusual fivefold symmetry and relationship to chordates. Species such as the slate pencil urchin are popular in aquariums, where they are useful for controlling algae. Fossil urchins have been used as protective amulets.


title: Sea urchin

text: Sea urchins are members of the phylum Echinodermata, which also includes sea stars, sea cucumbers, brittle stars, and crinoids. Like other echinoderms, they have five-fold symmetry (called pentamerism) and move by means of hundreds of tiny, transparent, adhesive "tube feet". The symmetry is not obvious in the living animal, but is easily visible in the dried test.


title: Sea urchin

text: Specifically, the term "sea urchin" refers to the "regular echinoids", which are symmetrical and globular, and includes several different taxonomic groups, with two subclasses : Euechinoidea ("modern" sea urchins, including irregular ones) and Cidaroidea or "slate-pencil urchins", which have very thick, blunt spines, with algae and sponges growing on them. The "irregular" sea urchins are an infra-class inside the Euechinoidea, called Irregularia, and include Atelostomata and Neognathostomata. Irregular echinoids include: flattened sand dollars, sea biscuits, and heart urchins.


title: Sea urchin

text: Together with sea cucumbers (Holothuroidea), they make up the subphylum Echinozoa, which is characterized by a globoid shape without arms or projecting rays. Sea cucumbers and the irregular echinoids have secondarily evolved diverse shapes. Although many sea cucumbers have branched tentacles surrounding their oral openings, these have originated from modified tube feet and are not homologous to the arms of the crinoids, sea stars, and brittle stars.


title: Sea urchin

text: Urchins typically range in size from , although the largest species can reach up to . They have a rigid, usually spherical body bearing moveable spines, which gives the class the name "Echinoidea" (from the Greek 'spine'). The name "urchin" is an old word for hedgehog, which sea urchins resemble; they have archaically been called sea hedgehogs. The name is derived from Old French , from Latin ('hedgehog').


title: Sea urchin

text: Like other echinoderms, sea urchin early larvae have bilateral symmetry, but they develop five-fold symmetry as they mature. This is most apparent in the "regular" sea urchins, which have roughly spherical bodies with five equally sized parts radiating out from their central axes. The mouth is at the base of the animal and the anus at the top; the lower surface is described as "oral" and the upper surface as "aboral".


title: Sea urchin

text: Several sea urchins, however, including the sand dollars, are oval in shape, with distinct front and rear ends, giving them a degree of bilateral symmetry. In these urchins, the upper surface of the body is slightly domed, but the underside is flat, while the sides are devoid of tube feet. This "irregular" body form has evolved to allow the animals to burrow through sand or other soft materials.


title: Sea urchin

text: Sea urchins might appear to be incapable of moving but this is a false impression. In some cases, the most visible sign of life is the spines, which are attached to ball-and-socket joints and can point in any direction; in most urchins, touch elicits a prompt reaction from the spines, which converge toward the touched point. Sea urchins have no visible eyes, legs, or means of propulsion, but can move freely but slowly over hard surfaces using adhesive tube feet, working in conjunction with the spines.


title: Sea urchin

text: The internal organs are enclosed in a hard shell or test composed of fused plates of calcium carbonate covered by a thin dermis and epidermis. The test is rigid, and divides into five ambulacral grooves separated by five interambulacral areas. Each of these areas consists of two rows of plates, so the sea urchin test includes 20 rows of plates in total. The plates are covered in rounded tubercles which contain the sockets to which the spines are attached by ball and socket joints. The inner surface of the test is lined by peritoneum. Sea urchins convert aqueous carbon dioxide using a catalytic process involving nickel into the calcium carbonate portion of the test.


title: Sea urchin

text: Most species have two series of spines, primary (long) and secondary (short), distributed over the surface of the body, with the shortest at the poles and the longest at the equator. The spines are usually hollow and cylindrical. Contraction of the muscular sheath that covers the test causes the spines to lean in one direction or another, while an inner sheath of collagen fibres can reversibly change from soft to rigid which can lock the spine in one position. Located among the spines are several types of pedicellaria, moveable stalked structures with jaws.


title: Sea urchin

text: Sea urchins move by walking, using their many flexible tube feet in a way similar to that of starfish; regular sea urchins do not have any favourite walking direction. The tube feet protrude through pairs of pores in the test, and are operated by a water vascular system; this works through hydraulic pressure, allowing the sea urchin to pump water into and out of the tube feet. During locomotion, the tube feet are assisted by the spines which can be used for pushing the body along or to lift the test off the substrate. Movement is generally related to feeding, with the red sea urchin ("Mesocentrotus franciscanus") managing about a day when there is ample food, and up to a day where there is not. An inverted sea urchin can right itself by progressively attaching and detaching its tube feet and manipulating its spines to roll its body upright. Some species bury themselves in soft sediment using their spines, and "Paracentrotus lividus" uses its jaws to burrow into soft rocks.


title: Sea urchin

text: The mouth lies in the centre of the oral surface in regular urchins, or towards one end in irregular urchins. It is surrounded by lips of softer tissue, with numerous small, embedded bony pieces. This area, called the peristome, also includes five pairs of modified tube feet and, in many species, five pairs of gills. The jaw apparatus consists of five strong arrow-shaped plates known as pyramids, the ventral surface of each of which has a toothband with a hard tooth pointing towards the centre of the mouth. Specialised muscles control the protrusion of the apparatus and the action of the teeth, and the animal can grasp, scrape, pull and tear. The structure of the mouth and teeth have been found to be so efficient at grasping and grinding that similar structures have been tested for use in real-world applications.


title: Sea urchin

text: On the upper surface of the test at the aboral pole is a membrane, the periproct, which surrounds the anus. The periproct contains a variable number of hard plates, five of which, the genital plates, contain the gonopores, and one is modified to contain the madreporite, which is used to balance the water vascular system.


title: Sea urchin

text: The mouth of most sea urchins is made up of five calcium carbonate teeth or plates, with a fleshy, tongue-like structure within. The entire chewing organ is known as Aristotle's lantern from Aristotle's description in his "History of Animals" (translated by D'Arcy Thompson):


title: Sea urchin

text: However, this has recently been proven to be a mistranslation. Aristotle's lantern is actually referring to the whole shape of sea urchins, which look like the ancient lamps of Aristotle's time.


title: Sea urchin

text: Heart urchins are unusual in not having a lantern. Instead, the mouth is surrounded by cilia that pull strings of mucus containing food particles towards a series of grooves around the mouth.


title: Sea urchin

text: The lantern, where present, surrounds both the mouth cavity and the pharynx. At the top of the lantern, the pharynx opens into the esophagus, which runs back down the outside of the lantern, to join the small intestine and a single caecum. The small intestine runs in a full circle around the inside of the test, before joining the large intestine, which completes another circuit in the opposite direction. From the large intestine, a rectum ascends towards the anus. Despite the names, the small and large intestines of sea urchins are in no way homologous to the similarly named structures in vertebrates.


title: Sea urchin

text: Digestion occurs in the intestine, with the caecum producing further digestive enzymes. An additional tube, called the siphon, runs beside much of the intestine, opening into it at both ends. It may be involved in resorption of water from food.


title: Sea urchin

text: The water vascular system leads downwards from the madreporite through the slender stone canal to the ring canal, which encircles the oesophagus. Radial canals lead from here through each ambulacral area to terminate in a small tentacle that passes through the ambulacral plate near the aboral pole. Lateral canals lead from these radial canals, ending in ampullae. From here, two tubes pass through a pair of pores on the plate to terminate in the tube feet.


title: Sea urchin

text: Sea urchins possess a hemal system with a complex network of vessels in the mesenteries around the gut, but little is known of the functioning of this system. However, the main circulatory fluid fills the general body cavity, or coelom. This coelomic fluid contains phagocytic coelomocytes, which move through the vascular and hemal systems and are involved in internal transport and gas exchange. The coelomocytes are an essential part of blood clotting, but also collect waste products and actively remove them from the body through the gills and tube feet.


title: Sea urchin

text: Most sea urchins possess five pairs of external gills attached to the peristomial membrane around their mouths. These thin-walled projections of the body cavity are the main organs of respiration in those urchins that possess them. Fluid can be pumped through the gills' interiors by muscles associated with the lantern, but this does not provide a continuous flow, and occurs only when the animal is low in oxygen. Tube feet can also act as respiratory organs, and are the primary sites of gas exchange in heart urchins and sand dollars, both of which lack gills. The inside of each tube foot is divided by a septum which reduces diffusion between the incoming and outgoing streams of fluid.


title: Sea urchin

text: The nervous system of sea urchins has a relatively simple layout. With no true brain, the neural center is a large nerve ring encircling the mouth just inside the lantern. From the nerve ring, five nerves radiate underneath the radial canals of the water vascular system, and branch into numerous finer nerves to innervate the tube feet, spines, and pedicellariae.


title: Sea urchin

text: Sea urchins are sensitive to touch, light, and chemicals. There are numerous sensitive cells in the epithelium, especially in the spines, pedicellaria and tube feet, and around the mouth. Although they do not have eyes or eye spots (except for diadematids, which can follow a threat with their spines), the entire body of most regular sea urchins might function as a compound eye. In general, sea urchins are negatively attracted to light, and seek to hide themselves in crevices or under objects. Most species, apart from pencil urchins, have statocysts in globular organs called spheridia. These are stalked structures and are located within the ambulacral areas; their function is to help in gravitational orientation.


title: Sea urchin

text: Sea urchins are dioecious, having separate male and female sexes, although no distinguishing features are visible externally. In addition to their role in reproduction, the gonads are also nutrient storing organs, and are made up of two main type of cells: germ cells, and somatic cells called nutritive phagocytes. Regular sea urchins have five gonads, lying underneath the interambulacral regions of the test, while the irregular forms mostly have four, with the hindmost gonad being absent; heart urchins have three or two. Each gonad has a single duct rising from the upper pole to open at a gonopore lying in one of the genital plates surrounding the anus. Some burrowing sand dollars have an elongated papilla that enables the liberation of gametes above the surface of the sediment. The gonads are lined with muscles underneath the peritoneum, and these allow the animal to squeeze its gametes through the duct and into the surrounding sea water, where fertilization takes place.


title: Sea urchin

text: During early development, the sea urchin embryo undergoes 10 cycles of cell division, resulting in a single epithelial layer enveloping the blastocoel. The embryo then begins gastrulation, a multipart process which dramatically rearranges its structure by invagination to produce the three germ layers, involving an epithelial-mesenchymal transition; primary mesenchyme cells move into the blastocoel and become mesoderm. It has been suggested that epithelial polarity together with planar cell polarity might be sufficient to drive gastrulation in sea urchins.


title: Sea urchin

text: An unusual feature of sea urchin development is the replacement of the larva's bilateral symmetry by the adult's broadly fivefold symmetry. During cleavage, mesoderm and small micromeres are specified. At the end of gastrulation, cells of these two types form coelomic pouches. In the larval stages, the adult rudiment grows from the left coelomic pouch; after metamorphosis, that rudiment grows to become the adult. The animal-vegetal axis is established before the egg is fertilized. The oral-aboral axis is specified early in cleavage, and the left-right axis appears at the late gastrula stage.


title: Sea urchin

text: In most cases, the female's eggs float freely in the sea, but some species hold onto them with their spines, affording them a greater degree of protection. The unfertilized egg meets with the free-floating sperm released by males, and develops into a free-swimming blastula embryo in as few as 12 hours. Initially a simple ball of cells, the blastula soon transforms into a cone-shaped echinopluteus larva. In most species, this larva has 12 elongated arms lined with bands of cilia that capture food particles and transport them to the mouth. In a few species, the blastula contains supplies of nutrient yolk and lacks arms, since it has no need to feed.


title: Sea urchin

text: Several months are needed for the larva to complete its development, the change into the adult form beginning with the formation of test plates in a juvenile rudiment which develops on the left side of the larva, its axis being perpendicular to that of the larva. Soon, the larva sinks to the bottom and metamorphoses into a juvenile urchin in as little as one hour. In some species, adults reach their maximum size in about five years. The purple urchin becomes sexually mature in two years and may live for twenty.


title: Sea urchin

text: Sea urchins feed mainly on algae, so they are primarily herbivores, but can feed on sea cucumbers and a wide range of invertebrates, such as mussels, polychaetes, sponges, brittle stars, and crinoids, making them omnivores, consumers at a range of trophic levels.


title: Sea urchin

text: Mass mortality of sea urchins was first reported in the 1970s, but diseases in sea urchins had been little studied before the advent of aquaculture. In 1981, bacterial "spotting disease" caused almost complete mortality in juvenile "Pseudocentrotus depressus" and "Hemicentrotus pulcherrimus", both cultivated in Japan; the disease recurred in succeeding years. It was divided into a cool-water "spring" disease and a hot-water "summer" form. Another condition, bald sea urchin disease, causes loss of spines and skin lesions and is believed to be bacterial in origin.


title: Sea urchin

text: Adult sea urchins are usually well protected against most predators by their strong and sharp spines, which can be venomous in some species. The small urchin clingfish lives among the spines of urchins such as "Diadema"; juveniles feed on the pedicellariae and sphaeridia, adult males choose the tube feet and adult females move away to feed on shrimp eggs and molluscs.


title: Sea urchin

text: Sea urchins are one of the favourite foods of many lobsters, crabs, triggerfish, California sheephead, sea otter and wolf eels (which specialise in sea urchins). All these animals carry particular adaptations (teeth, pincers, claws) and a strength that allow them to overcome the excellent protective features of sea urchins. Left unchecked by predators, urchins devastate their environments, creating what biologists call an urchin barren, devoid of macroalgae and associated fauna. Sea urchins graze on the lower stems of kelp, causing the kelp to drift away and die. Loss of the habitat and nutrients provided by kelp forests leads to profound cascade effects on the marine ecosystem. Sea otters have re-entered British Columbia, dramatically improving coastal ecosystem health.


title: Sea urchin

text: The spines, long and sharp in some species, protect the urchin from predators. Some tropical sea urchins like Diadematidae, Echinothuriidae and Toxopneustidae have venomous spines. Other creatures also make use of these defences; crabs, shrimps and other organisms shelter among the spines, and often adopt the colouring of their host. Some crabs in the Dorippidae family carry sea urchins, starfish, sharp shells or other protective objects in their claws.


title: Sea urchin

text: Pedicellaria are a good means of defense against ectoparasites, but not a panacea as some of them actually feed on it. The hemal system defends against endoparasites.


title: Sea urchin

text: Sea urchins are established in most seabed habitats from the intertidal downwards, at an extremely wide range of depths. Some species, such as "Cidaris abyssicola", can live at depths of several kilometres. Many genera are found in only the abyssal zone, including many cidaroids, most of the genera in the Echinothuriidae family, and the "cactus urchins" "Dermechinus". One of the deepest-living families is the Pourtalesiidae, strange bottle-shaped irregular sea urchins that live in only the hadal zone and have been collected as deep as 6850 metres beneath the surface in the Sunda Trench. Nevertheless, this makes sea urchin the class of echinoderms living the least deep, compared to brittle stars, starfish and crinoids that remain abundant below and sea cucumbers which have been recorded from .


title: Sea urchin

text: Population densities vary by habitat, with more dense populations in barren areas as compared to kelp stands. Even in these barren areas, greatest densities are found in shallow water. Populations are generally found in deeper water if wave action is present. Densities decrease in winter when storms cause them to seek protection in cracks and around larger underwater structures.


title: Sea urchin

text: The shingle urchin ("Colobocentrotus atratus"), which lives on exposed shorelines, is particularly resistant to wave action. It is one of the few sea urchin that can survive many hours out of water.


title: Sea urchin

text: Sea urchins can be found in all climates, from warm seas to polar oceans. The larvae of the polar sea urchin "Sterechinus neumayeri" have been found to use energy in metabolic processes twenty-five times more efficiently than do most other organisms. Despite their presence in nearly all the marine ecosystems, most species are found on temperate and tropical coasts, between the surface and some tens of meters deep, close to photosynthetic food sources.


title: Sea urchin

text: The earliest echinoid fossils date to the Middle Ordovician period ("circa" 465 Mya). There is a rich fossil record, their hard tests made of calcite plates surviving in rocks from every period since then.


title: Sea urchin

text: Spines are present in some well-preserved specimens, but usually only the test remains. Isolated spines are common as fossils. Some Jurassic and Cretaceous Cidaroida had very heavy, club-shaped spines.


title: Sea urchin

text: Most fossil echinoids from the Paleozoic era are incomplete, consisting of isolated spines and small clusters of scattered plates from crushed individuals, mostly in Devonian and Carboniferous rocks. The shallow-water limestones from the Ordovician and Silurian periods of Estonia are famous for echinoids. Paleozoic echinoids probably inhabited relatively quiet waters. Because of their thin tests, they would certainly not have survived in the wave-battered coastal waters inhabited by many modern echinoids. Echinoids declined to near extinction at the end of the Paleozoic era, with just six species known from the Permian period. Only two lineages survived this period's massive extinction and into the Triassic: the genus "Miocidaris", which gave rise to modern cidaroida (pencil urchins), and the ancestor that gave rise to the euechinoids. By the upper Triassic, their numbers increased again. Cidaroids have changed very little since the Late Triassic, and are the only Paleozoic echinoid group to have survived.


title: Sea urchin

text: The euechinoids diversified into new lineages in the Jurassic and Cretaceous periods, and from them emerged the first irregular echinoids (the Atelostomata) during the early Jurassic.


title: Sea urchin

text: Some echinoids, such as "Micraster" in the chalk of the Cretaceous period, serve as zone or index fossils. Because they are abundant and evolved rapidly, they enable geologists to date the surrounding rocks.


title: Sea urchin

text: In the Paleogene and Neogene periods ("circa" 66 to 1.8 Mya), sand dollars (Clypeasteroida) arose. Their distinctive, flattened tests and tiny spines were adapted to life on or under loose sand in shallow water, and they are abundant as fossils in southern European limestones and sandstones.


title: Sea urchin

text: Echinoids are deuterostome animals, like the chordates. A 2014 analysis of 219 genes from all classes of echinoderms gives the following phylogenetic tree. Approximate dates of branching of major clades are shown in millions of years ago (mya).


title: Sea urchin

text: The phylogenetic study from 2022 presents a different topology of the Euechinoidea phylogenetic tree. Irregularia are sister group of Echinacea (including Salenioida) forming a common clade Carinacea, basal groups Aspidodiadematoida, Diadematoida, Echinothurioida, Micropygoida, and Pedinoida are comprised in a common basal clade Aulodonta.


title: Sea urchin

text: These are a common source of injury to ocean swimmers, especially along coastal surfaces where coral with stationary sea urchins are present. Their stings vary in severity depending on the species. Their spines can be venomous or cause infection. Granuloma and staining of the skin from the natural dye inside the sea urchin can also occur. Breathing problems may indicate a serious reaction to toxins in the sea urchin. They inflict a painful wound when they penetrate human skin, but are not themselves dangerous if fully removed promptly; if left in the skin, further problems may occur.


title: Sea urchin

text: Sea urchins are traditional model organisms in developmental biology. This use originated in the 1800s, when their embryonic development became easily viewed by microscopy. The transparency of the urchin's eggs enabled them to be used to observe that sperm cells actually fertilize ova. They continue to be used for embryonic studies, as prenatal development continues to seek testing for fatal diseases. Sea urchins are being used in longevity studies for comparison between the young and old of the species, particularly for their ability to regenerate tissue as needed. Scientists at the University of St Andrews have discovered a genetic sequence, the '2A' region, in sea urchins previously thought to have belonged only to viruses that afflict humans like foot-and-mouth disease virus.


title: Sea urchin

text: More recently, Eric H. Davidson and Roy John Britten argued for the use of urchins as a model organism due to their easy availability, high fecundity, and long lifespan. Beyond embryology, urchins provide an opportunity to research cis-regulatory elements.


title: Sea urchin

text: Oceanography has taken an interest in monitoring the health of urchins and their populations as a way to assess overall ocean acidification, temperatures, and ecological impacts.


title: Sea urchin

text: The organism's evolutionary placement and unique embryology with five-fold symmetry were the major arguments in the proposal to seek the sequencing of its genome. Importantly, urchins act as the closest living relative to chordates and thus are of interest for the light they can shed on the evolution of vertebrates. The genome of "Strongylocentrotus purpuratus" was completed in 2006 and established homology between sea urchin and vertebrate immune system-related genes. Sea urchins code for at least 222 Toll-like receptor genes and over 200 genes related to the Nod-like-receptor family found in vertebrates. This increases its usefulness as a valuable model organism for studying the evolution of innate immunity. The sequencing also revealed that while some genes were thought to be limited to vertebrates, there were also innovations that have previously never been seen outside the chordate classification, such as immune transcription factors PU.1 and SPIB.


title: Sea urchin

text: The gonads of both male and female sea urchins, usually called sea urchin roe or corals, are culinary delicacies in many parts of the world, especially Japan. In Japan, sea urchin is known as , and its roe can retail for as much as ¥40,000 ($360) per kilogram; it is served raw as "sashimi" or in "sushi", with soy sauce and "wasabi". Japan imports large quantities from the United States, South Korea, and other producers. Japan consumes 50,000 tons annually, amounting to over 80% of global production. Japanese demand for sea urchins has raised concerns about overfishing.


title: Sea urchin

text: In Mediterranean cuisines, "Paracentrotus lividus" is often eaten raw, or with lemon, and known as "ricci" on Italian menus where it is sometimes used in pasta sauces. It can also flavour omelettes, scrambled eggs, fish soup, mayonnaise, béchamel sauce for tartlets, the "boullie" for a soufflé, or Hollandaise sauce to make a fish sauce. In Chilean cuisine, it is served raw with lemon, onions, and olive oil. Though the edible "Strongylocentrotus droebachiensis" is found in the North Atlantic, it is not widely eaten. However, sea urchins (called "uutuk" in Alutiiq) are commonly eaten by the Alaska Native population around Kodiak Island. It is commonly exported, mostly to Japan.


title: Sea urchin

text: On the Pacific Coast of North America, "Strongylocentrotus franciscanus" was praised by Euell Gibbons; "Strongylocentrotus purpuratus" is also eaten.


title: Sea urchin

text: Native Americans in California are also known to eat sea urchins. The coast of Southern California is known as a source of high quality "uni", with divers picking sea urchin from kelp beds in depths as deep as 24 m/80 ft. As of 2013, the state was limiting the practice to 300 sea urchin diver licenses.


title: Sea urchin

text: In New Zealand, "Evechinus chloroticus", known as "kina" in Māori, is a delicacy, traditionally eaten raw. Though New Zealand fishermen would like to export them to Japan, their quality is too variable.


title: Sea urchin

text: Some species of sea urchins, such as the slate pencil urchin ("Eucidaris tribuloides"), are commonly sold in aquarium stores. Some species are effective at controlling filamentous algae, and they make good additions to an invertebrate tank.


title: Sea urchin

text: A folk tradition in Denmark and southern England imagined sea urchin fossils to be thunderbolts, able to ward off harm by lightning or by witchcraft, as an apotropaic symbol. Another version supposed they were petrified eggs of snakes, able to protect against heart and liver disease, poisons, and injury in battle, and accordingly they were carried as amulets. These were, according to the legend, created by magic from foam made by the snakes at midsummer.


title: Soybean

text: The soybean, soy bean, or soya bean ("Glycine max") is a species of legume native to East Asia, widely grown for its edible bean, which has numerous uses.


title: Soybean

text: Traditional unfermented food uses of soybeans include soy milk, from which tofu and tofu skin are made. Fermented soy foods include soy sauce, fermented bean paste, nattō, and tempeh. Fat-free (defatted) soybean meal is a significant and cheap source of protein for animal feeds and many packaged meals. For example, soybean products, such as textured vegetable protein (TVP), are ingredients in many meat and dairy substitutes.


title: Soybean

text: Soybeans contain significant amounts of phytic acid, dietary minerals and B vitamins. Soy vegetable oil, used in food and industrial applications, is another product of processing the soybean crop. Soybean is the most important protein source for feed farm animals (that in turn yields animal protein for human consumption).


title: Soybean

text: The etymology of the genus, "Glycine", comes from Linnaeus. When naming the genus, Linnaeus observed that one of the species within the genus had a sweet root. Based on the sweetness, the Greek word for sweet, glykós, was Latinized. The genus name is not related to the amino acid glycine.


title: Soybean

text: The genus "Glycine" is divided into two subgenera, "Glycine" and "Soja". The subgenus "Soja" (Moench) F.J. Herm. includes the cultivated soybean, "Glycine max" (L.) Merr., and the wild soybean, "Glycine soja" Sieb. & Zucc. Both species are annuals. "Glycine soja" is the wild ancestor of "Glycine max", and grows wild in China, Japan, Korea and Russia. The subgenus "Glycine" consists of at least 25 wild perennial species: for example, "Glycine canescens" F.J. Herm. and "G. tomentella" Hayata, both found in Australia and Papua New Guinea. Perennial soybean ("Neonotonia wightii") originated in Africa and is now a widespread pasture crop in the tropics.


title: Soybean

text: Like some other crops of long domestication, the relationship of the modern soybean to wild-growing species can no longer be traced with any degree of certainty. It is a cultural variety with a very large number of cultivars.


title: Soybean

text: Like most plants, soybeans grow in distinct morphological stages as they develop from seeds into fully mature plant.


title: Soybean

text: The first stage of growth is germination, a method which first becomes apparent as a seed's radicle emerges. This is the first stage of root growth and occurs within the first 48 hours under ideal growing conditions. The first photosynthetic structures, the cotyledons, develop from the hypocotyl, the first plant structure to emerge from the soil. These cotyledons both act as leaves and as a source of nutrients for the immature plant, providing the seedling nutrition for its first 7 to 10 days.


title: Soybean

text: The first true leaves develop as a pair of single blades. Subsequent to this first pair, mature nodes form compound leaves with three blades. Mature trifoliolate leaves, having three to four leaflets per leaf, are often between long and broad. Under ideal conditions, stem growth continues, producing new nodes every four days. Before flowering, roots can grow per day. If rhizobia are present, root nodulation begins by the time the third node appears. Nodulation typically continues for 8 weeks before the symbiotic infection process stabilizes. The final characteristics of a soybean plant are variable, with factors such as genetics, soil quality, and climate affecting its form; however, fully mature soybean plants are generally between in height and have rooting depths between .


title: Soybean

text: Flowering is triggered by day length, often beginning once days become shorter than 12.8 hours. This trait is highly variable however, with different varieties reacting differently to changing day length. Soybeans form inconspicuous, self-fertile flowers which are borne in the axil of the leaf and are white, pink or purple. Though they do not require pollination, they are attractive to bees, because they produce nectar that is high in sugar content. Depending on the soybean variety, node growth may cease once flowering begins. Strains that continue nodal development after flowering are termed "indeterminates" and are best suited to climates with longer growing seasons. Often soybeans drop their leaves before the seeds are fully mature.


title: Soybean

text: The fruit is a hairy pod that grows in clusters of three to five, each pod is long and usually contains two to four (rarely more) seeds 5–11 mm in diameter. Soybean seeds come in a wide variety of sizes and hull colors such as black, brown, yellow, and green. Variegated and bicolored seed coats are also common.


title: Soybean

text: The hull of the mature bean is hard, water-resistant, and protects the cotyledon and hypocotyl (or "germ") from damage. If the seed coat is cracked, the seed will not germinate. The scar, visible on the seed coat, is called the hilum (colors include black, brown, buff, gray and yellow) and at one end of the hilum is the micropyle, or small opening in the seed coat which can allow the absorption of water for sprouting.


title: Soybean

text: Some seeds such as soybeans containing very high levels of protein can undergo desiccation, yet survive and revive after water absorption. A. Carl Leopold began studying this capability at the Boyce Thompson Institute for Plant Research at Cornell University in the mid-1980s. He found soybeans and corn to have a range of soluble carbohydrates protecting the seed's cell viability. Patents were awarded to him in the early 1990s on techniques for protecting biological membranes and proteins in the dry state.


title: Soybean

text: Like many legumes, soybeans can fix atmospheric nitrogen, due to the presence of symbiotic bacteria from the Rhizobia group.


title: Soybean

text: Together, protein and soybean oil content account for 56% of dry soybeans by weight (36% protein and 20% fat, table). The remainder consists of 30% carbohydrates, 9% water and 5% ash (table). Soybeans comprise approximately 8% seed coat or hull, 90% cotyledons and 2% hypocotyl axis or germ.


title: Soybean

text: A 100-gram reference quantity of raw soybeans supplies of food energy and are 9% water, 30% carbohydrates, 20% total fat and 36% protein (table).


title: Soybean

text: Soybeans are a rich source of essential nutrients, providing in a 100-gram serving (raw, for reference) high contents of the Daily Value (DV) especially for protein (36% DV), dietary fiber (37%), iron (121%), manganese (120%), phosphorus (101%) and several B vitamins, including folate (94%) (table). High contents also exist for vitamin K, magnesium, zinc and potassium (table).


title: Soybean

text: For human consumption, soybeans must be cooked with "wet" heat to destroy the trypsin inhibitors (serine protease inhibitors). Raw soybeans, including the immature green form, are toxic to all monogastric animals.


title: Soybean

text: Most soy protein is a relatively heat-stable storage protein. This heat stability enables soy food products requiring high temperature cooking, such as tofu, soy milk and textured vegetable protein (soy flour) to be made. Soy protein is essentially identical to the protein of other legume seeds and pulses.


title: Soybean

text: Soy is a good source of protein for vegetarians and vegans or for people who want to reduce the amount of meat they eat, according to the US Food and Drug Administration:


title: Soybean

text: Although soybeans have high protein content, soybeans also contain high levels of protease inhibitors, which can prevent digestion. Protease inhibitors are reduced by cooking soybeans, and are present in low levels in soy products such as tofu and soy milk.


title: Soybean

text: The Protein Digestibility Corrected Amino Acid Score (PDCAAS) of soy protein is the nutritional equivalent of meat, eggs, and casein for human growth and health. Soybean protein isolate has a biological value of 74, whole soybeans 96, soybean milk 91, and eggs 97.


title: Soybean

text: All spermatophytes, except for the family of grasses and cereals (Poaceae), contain 7S (vicilin) and 11S (legumin) soy protein-like globulin storage proteins; or only one of these globulin proteins. S denotes Svedberg, sedimentation coefficients. Oats and rice are anomalous in that they also contain a majority of soybean-like protein. Cocoa, for example, contains the 7S globulin, which contributes to cocoa/chocolate taste and aroma, whereas coffee beans (coffee grounds) contain the 11S globulin responsible for coffee's aroma and flavor.


title: Soybean

text: Vicilin and legumin proteins belong to the cupin superfamily, a large family of functionally diverse proteins that have a common origin and whose evolution can be followed from bacteria to eukaryotes including animals and higher plants.


title: Soybean

text: 2S albumins form a major group of homologous storage proteins in many dicot species and in some monocots but not in grasses (cereals). Soybeans contain a small but significant 2S storage protein. 2S albumin are grouped in the prolamin superfamily. Other allergenic proteins included in this 'superfamily' are the non-specific plant lipid transfer proteins, alpha amylase inhibitor, trypsin inhibitors, and prolamin storage proteins of cereals and grasses.


title: Soybean

text: Peanuts, for instance, contain 20% 2S albumin but only 6% 7S globulin and 74% 11S. It is the high 2S albumin and low 7S globulin that is responsible for the relatively low lysine content of peanut protein compared to soy protein.


title: Soybean

text: The principal soluble carbohydrates of mature soybeans are the disaccharide sucrose (range 2.5–8.2%), the trisaccharide raffinose (0.1–1.0%) composed of one sucrose molecule connected to one molecule of galactose, and the tetrasaccharide stachyose (1.4 to 4.1%) composed of one sucrose connected to two molecules of galactose. While the oligosaccharides raffinose and stachyose protect the viability of the soybean seed from desiccation (see above section on physical characteristics) they are not digestible sugars, so contribute to flatulence and abdominal discomfort in humans and other monogastric animals, comparable to the disaccharide trehalose. Undigested oligosaccharides are broken down in the intestine by native microbes, producing gases such as carbon dioxide, hydrogen, and methane.


title: Soybean

text: Since soluble soy carbohydrates are found in the whey and are broken down during fermentation, soy concentrate, soy protein isolates, tofu, soy sauce, and sprouted soybeans are without flatus activity. On the other hand, there may be some beneficial effects to ingesting oligosaccharides such as raffinose and stachyose, namely, encouraging indigenous bifidobacteria in the colon against putrefactive bacteria.


title: Soybean

text: The insoluble carbohydrates in soybeans consist of the complex polysaccharides cellulose, hemicellulose, and pectin. The majority of soybean carbohydrates can be classed as belonging to dietary fiber.


title: Soybean

text: Raw soybeans are 20% fat, including saturated fat (3%), monounsaturated fat (4%) and polyunsaturated fat, mainly as linoleic acid (table).


title: Soybean

text: Within soybean oil or the lipid portion of the seed is contained four phytosterols: stigmasterol, sitosterol, campesterol, and brassicasterol accounting for about 2.5% of the lipid fraction; and which can be converted into steroid hormones. Additionally soybeans are a rich source of sphingolipids.


title: Soybean

text: Soy contains isoflavones—polyphenolic compounds, produced by legumes including peanuts and chickpeas. Isoflavones are closely related to flavonoids found in other plants, vegetables and flowers.


title: Soybean

text: Soy contains the phytoestrogen coumestans, also are found in beans and split-peas, with the best sources being alfalfa, clover, and soybean sprouts. Coumestrol, an isoflavone coumarin derivative, is the only coumestan in foods.


title: Soybean

text: Saponins, a class of natural surfactants (soaps), are sterols that are present in small amounts in various plant foods, including soybeans, other legumes, and cereals, such as oats.


title: Soybean

text: The following table shows the nutrient content of green soybean and other major staple foods, each in respective raw form on a dry weight basis to account for their different water contents. Raw soybeans, however, are not edible and cannot be digested. These must be sprouted, or prepared and cooked for human consumption. In sprouted and cooked form, the relative nutritional and anti-nutritional contents of each of these grains is remarkably different from that of raw form of these grains reported in this table. The nutritional value of soybean and each cooked staple depends on the processing and the method of cooking: boiling, frying, roasting, baking, etc.


title: Soybean

text: During World War II, soybeans became important in both North America and Europe chiefly as substitutes for other protein foods and as a source of edible oil. During the war, the soybean was discovered as fertilizer due to nitrogen fixation by the United States Department of Agriculture.


title: Soybean

text: Cultivation is successful in climates with hot summers, with optimum growing conditions in mean temperatures of ; temperatures of below and over stunt growth significantly. They can grow in a wide range of soils, with optimum growth in moist alluvial soils with good organic content. Soybeans, like most legumes, perform nitrogen fixation by establishing a symbiotic relationship with the bacterium "Bradyrhizobium japonicum" (syn. "Rhizobium japonicum"; Jordan 1982). This ability to fix nitrogen allows farmers to reduce nitrogen fertilizer use and increase yields when growing other crops in rotation with soy. There may be some trade-offs, however, in the long-term abundance of organic material in soils where soy and other crops (for example, corn) are grown in rotation. For best results, though, an inoculum of the correct strain of bacteria should be mixed with the soybean (or any legume) seed before planting. Modern crop cultivars generally reach a height of around , and take 80–120 days from sowing to harvesting.


title: Soybean

text: Soil scientists Edson Lobato (Brazil), Andrew McClung (U.S.), and Alysson Paolinelli (Brazil) were awarded the 2006 World Food Prize for transforming the ecologically biodiverse savannah of the Cerrado region of Brazil into highly productive cropland that could grow profitable soybeans.


title: Soybean

text: Human sewage sludge can be used as fertilizer to grow soybeans. Soybeans grown in sewage sludge likely contain elevated concentrations of metals.


title: Soybean

text: Soybean plants are vulnerable to a wide range of bacterial diseases, fungal diseases, viral diseases and parasites.


title: Soybean

text: The primary bacterial diseases include bacterial blight, bacterial pustule and downy mildew affecting the soybean plant.


title: Soybean

text: Soybean cyst nematode is the worst pest of soybean in the US. Losses of 30% or 40% are common even without symptoms.


title: Soybean

text: Soybeans are consumed by whitetail deer which may damage soybean plants through feeding, trampling and bedding, reducing crop yields by as much as 15%. Groundhogs are also a common pest in soybean fields, living in burrows underground and feeding nearby. One den of groundhogs can consume a tenth to a quarter of an acre of soybeans. Chemical repellents or firearms are effective for controlling pests in soybean fields.


title: Soybean

text: The vast majority of cultivars in the US have SCN resistance, but rely on only one breeding line (PI 88788) as their sole source of resistance. (The resistance genes provided by PI 88788, Peking, and PI 90763 were characterized in 1997.) As a result, for example, in 2012 only 18 cultivars out of 807 recommended by the Iowa State University Extension had any ancestry outside of PI 88788. By 2020 the situation was still about the same: Of 849 there were 810 with some ancestry from PI 88788, 35 from Peking, and only 2 from PI 89772. (On the question of exclusively PI 88788 ancestry, that number was not available for 2020.) That was speculated to be in 2012—and was clearly by 2020—producing SCN populations that are virulent on PI 88788.


title: Soybean

text: In 2020, world production of soybeans was over 353 million tonnes, led by Brazil and the United States combined with 66% of the total (table). Production has dramatically increased across the globe since the 1960s, but particularly in South America after a cultivar that grew well in low latitudes was developed in the 1980s. The rapid growth of the industry has been primarily fueled by large increases in worldwide demand for meat products, particularly in developing countries like China, which alone accounts for more than 60% of imports.


title: Soybean

text: In spite of the Amazon "Soy Moratorium", soy production continues to play a significant role in deforestation when its indirect impacts are taken into account, as land used to grow soy continues to increase. This land either comes from pasture land (which increasingly supplants forested areas), or areas outside the Amazon not covered by the moratorium, such as the Cerrado region. Roughly one-fifth of deforestation can be attributed to expanding land use to produce oilseeds, primarily for soy and palm oil, whereas the expansion of beef production accounts for 41%. The main driver of deforestation is the global demand for meat, which in turn requires huge tracts of land to grow feed crops for livestock. Around 80% of the global soybean crop is used to feed livestock.


title: Soybean

text: Soybeans were a crucial crop in East Asia long before written records began. The origin of soy bean cultivation remains scientifically debated. The closest living relative of the soybean is "Glycine soja" (previously called "G. ussuriensis"), a legume native to central China. There is evidence for soybean domestication between 7000 and 6600 BC in China, between 5000 and 3000 BC in Japan and 1000 BC in Korea.


title: Soybean

text: The first unambiguously domesticated, cultigen-sized soybean was discovered in Korea at the Mumun-period Daundong site. Prior to fermented products such as fermented black soybeans ("douchi"), "jiang" (Chinese miso), soy sauce, tempeh, nattō, and miso, soy was considered sacred for its beneficial effects in crop rotation, and it was eaten by itself, and as bean curd and soy milk.


title: Soybean

text: Soybeans were introduced to Java in Malay Archipelago circa 13th century or probably earlier. By the 17th century through their trade with Far East, soybeans and its products were traded by European traders (Portuguese, Spanish, and Dutch) in Asia, and reached Indian Subcontinent by this period. By the 18th century, soybeans were introduced to the Americas and Europe from China. Soy was introduced to Africa from China in the late 19th century, and is now widespread across the continent.


title: Soybean

text: The cultivation of soybeans began in the eastern half of northern China by 2000 BC, but is almost certainly much older. The earliest documented evidence for the use of Glycine of any kind comes from charred plant remains of wild soybean recovered from Jiahu in Henan province China, a Neolithic site occupied between 9000 and 7800 calendar years ago (cal bp). An abundance of archeological charred soybean specimens have been found centered around this region.


title: Soybean

text: According to the ancient Chinese myth, in 2853 BC, the legendary Emperor Shennong of China proclaimed that five plants were sacred: soybeans, rice, wheat, barley, and millet. Early Chinese records mention that soybeans were a gift from the region of Yangtze River delta and Southeast China. The "Great Soviet Encyclopedia" claims soybean cultivation originated in China about 5000 years ago. Some scholars suggest that soybean originated in China and was domesticated about 3500 BC. Recent research, however, indicates that seeding of wild forms started early (before 5000 BC) in multiple locations throughout East Asia.


title: Soybean

text: The oldest preserved soybeans resembling modern varieties in size and shape were found in archaeological sites in Korea dated about 1000 BC. Radiocarbon dating of soybean samples recovered through flotation during excavations at the Early Mumun period Okbang site in Korea indicated soybean was cultivated as a food crop in around 1000–900 BC. Soybeans from the Jōmon period in Japan from 3000 BC are also significantly larger than wild varieties.


title: Soybean

text: Soybeans became an important crop by the Zhou Dynasty (c. 1046–256 BC) in China. However, the details of where, when, and under what circumstances soybean developed a close relationship with people are poorly understood. Soybean was unknown in South China before the Han period. From about the first century AD to the Age of Discovery (15–16th centuries), soybeans were introduced into across South and Southeast Asia. This spread was due to the establishment of sea and land trade routes. The earliest Japanese textual reference to the soybean is in the classic "Kojiki" ("Records of Ancient Matters"), which was completed in AD 712.


title: Soybean

text: Soybeans were mentioned as "kadêlê" (modern Indonesian term: ) in an old Javanese manuscript, Serat Sri Tanjung, which dates to 12th- to 13th-century Java. By the 13th century, the soybean had arrived and cultivated in Indonesia; it probably arrived much earlier however, carried by traders or merchants from Southern China.


title: Soybean

text: The earliest known reference to it as "tempeh" appeared in 1815 in the Serat Centhini manuscript. The development of tempeh fermented soybean cake probably took place earlier, circa 17th century in Java.


title: Soybean

text: By the 1600s, soy sauce spread from southern Japan across the region through the Dutch East India Company (VOC).


title: Soybean

text: The soybean probably arrived from southern China, moving southwest into northern parts of Indian subcontinent by this period.


title: Soybean

text: In 1603, "Vocabvlario da Lingoa de Iapam", a famous Japanese-Portuguese dictionary, was compiled and published by Jesuit priests in Nagasaki. It contains short but clear definitions for about 20 words related to soyfoods—the first in any European language.


title: Soybean

text: The Luso-Hispanic traders were familiar with soybeans and soybean product through their trade with Far East since at least the 17th century. However, it was not until the late 19th century that the first attempt to cultivate soybeans in the Iberian peninsula was undertaken. In 1880, the soybean was first cultivated in Portugal in the Botanical Gardens at Coimbra (Crespi 1935).


title: Soybean

text: In about 1910 in Spain the first attempts at Soybean cultivation were made by the Count of San Bernardo, who cultivated soybeans on his estates at Almillo (in southwest Spain) about 48 miles east-northeast of Seville.


title: Soybean

text: Soybeans were first introduced to North America from China in 1765, by Samuel Bowen, a former East India Company sailor who had visited China in conjunction with James Flint, the first Englishman legally permitted by the Chinese authorities to learn Chinese. The first "New World" soybean crop was grown on Skidaway Island, Georgia, in 1765 by Henry Yonge from seeds given him by Samuel Bowen. Bowen grew soy near Savannah, Georgia, possibly using funds from Flint, and made soy sauce for sale to England. Although soybean was introduced into North America in 1765, for the next 155 years, the crop was grown primarily for forage.


title: Soybean

text: In 1831, the first soy product "a few dozen India Soy" [sauce] arrived in Canada. Soybeans were probably first cultivated in Canada by 1855, and definitely in 1895 at Ontario Agricultural College.


title: Soybean

text: It was not until Lafayette Mendel and Thomas Burr Osborne showed that the nutritional value of soybean seeds could be increased by cooking, moisture or heat, that soy went from a farm animal feed to a human food.


title: Soybean

text: William Morse is considered the "father" of modern soybean agriculture in America. He and Charles Piper (Dr. C. V. Piper) took what was an unknown Oriental peasant crop in 1910 and transformed it into a "golden bean" for America, becoming one of America's largest farm crops and its most nutritious.


title: Soybean

text: Prior to the 1920 in the US, the soybean was mainly a forage crop, a source of oil, meal (for feed) and industrial products, with very little used as food. However, it took on an important role after World War I. During the Great Depression, the drought-stricken (Dust Bowl) regions of the United States were able to use soy to regenerate their soil because of its nitrogen-fixing properties. Farms were increasing production to meet with government demands, and Henry Ford became a promoter of soybeans. In 1931, Ford hired chemists Robert Boyer and Frank Calvert to produce artificial silk. They succeeded in making a textile fiber of spun soy protein fibers, hardened or tanned in a formaldehyde bath, which was given the name Azlon. It never reached the commercial market. Soybean oil was used by Ford in paint for the automobiles, as well as a fluid for shock absorbers.


title: Soybean

text: Prior to the 1970s, Asian-Americans and Seventh-Day Adventists were essentially the only users of soy foods in the United States. "The soy foods movement began in small pockets of the counterculture, notably the Tennessee commune named simply The Farm, but by the mid-1970s a vegetarian revival helped it gain momentum and even popular awareness through books such as "The Book of Tofu"."


title: Soybean

text: Although practically unseen in 1900, by 2000 soybean plantings covered more than 70 million acres, second only to corn, and it became America's largest cash crop. In 2021, 87,195 acres were planted, with the largest acreage in the states of Illinois, Iowa, and Minnesota.


title: Soybean

text: The soybean arrived in the Caribbean in the form of soy sauce made by Samuel Bowen in Savannah, Georgia, in 1767. It remains only a minor crop there, but its uses for human food are growing steadily.


title: Soybean

text: The soybean was first cultivated in Italy by 1760 in the Botanical Garden of Turin. During the 1780s, it was grown in at least three other botanical gardens in Italy. The first soybean product, soy oil, arrived in Anatolia during 1909 under Ottoman Empire. The first clear cultivation occurred in 1931. This was also the first time that soybeans were cultivated in Middle East. By 1939, soybeans were cultivated in Greece.


title: Soybean

text: Wild soybeans were discovered in northeastern Australia in 1770 by explorers Banks and Solander. In 1804, the first soyfood product ("Fine India Soy" [sauce]) was sold in Sydney. In 1879, the first domesticated soybeans arrived in Australia, a gift of the Minister of the Interior Department, Japan.


title: Soybean

text: The soybean was first cultivated in France by 1779 (and perhaps as early as 1740). The two key early people and organizations introducing the soybean to France were the Society of Acclimatization (starting in 1855) and Li Yu-ying (from 1910). Li started a large tofu factory, where the first commercial soyfoods in France were made.


title: Soybean

text: The soybean first arrived in Africa via Egypt in 1857. Soya Meme (Baked Soya) is produced in the village called Bame Awudome near Ho, the capital of the Volta Region of Ghana, by the Ewe people of Southeastern Ghana and southern Togo.


title: Soybean

text: In 1873, Professor Friedrich J. Haberlandt first became interested in soybeans when he obtained the seeds of 19 soybean varieties at the Vienna World Exposition (Wiener Weltausstellung). He cultivated these seeds in Vienna, and soon began to distribute them throughout Central and Western Europe. In 1875, he first grew the soybeans in Vienna, then in early 1876 he sent samples of seeds to seven cooperators in central Europe, who planted and tested the seeds in the spring of 1876, with good or fairly good results in each case. Most of the farmers who received seeds from him cultivated them, then reported their results. Starting in February 1876, he published these results first in various journal articles, and finally in his "magnum opus", Die Sojabohne (The Soybean) in 1878. In northern Europe, lupin (lupine) is known as the "soybean of the north".


title: Soybean

text: The soybean is first in cultivated Transcaucasia in Central Asia in 1876, by the Dungans. This region has never been important for soybean production.