Ehrlich was born in Philadelphia, Pennsylvania, the son of William Ehrlich and Ruth Rosenberg.
His father was a shirt salesman, his mother a Greek and Latin scholar and public school teacher.
Ehrlich's mother's Reform-Jewish German ancestors arrived in the United States in the 1840s, and his paternal grandparents emigrated there later from the Galician and Romanian part of the Austrian Empire.
During his childhood his family moved to Maplewood, New Jersey, where he attended Columbia High School, graduating in 1949.

Ehrlich earned a bachelor's degree in zoology from the University of Pennsylvania in 1953, an M.A. from the University of Kansas in 1955, and a Ph.D. from the University of Kansas in 1957, supervised by the prominent bee researcher Charles Duncan Michener (the title of his dissertation: "The Morphology, Phylogeny and Higher Classification of the Butterflies (Lepidoptera: Papilionoidea)").
During his studies he participated with surveys of insects in the areas of the Bering Sea and Canadian Arctic, and then with a National Institutes of Health fellowship, investigated the genetics and behavior of parasitic mites.
In 1959 he joined the faculty at Stanford University, being promoted to professor of biology in 1966.
By training he is an entomologist specializing in Lepidoptera (butterflies); he published a major paper about the evolution of plants and insects.

He was appointed to the Bing Professorship in 1977.

He is president of the Center for Conservation Biology at Stanford University.
He is a fellow of the American Association for the Advancement of Science, the United States National Academy of Sciences, the American Academy of Arts and Sciences and the American Philosophical Society.
Ehrlich was born in Philadelphia, Pennsylvania, the son of William Ehrlich and Ruth Rosenberg. His father was a shirt salesman, his mother a Greek and Latin scholar and public school teacher. Ehrlich's mother's Reform-Jewish German ancestors arrived in the United States in the 1840s, and his paternal grandparents emigrated there later from the Galician and Romanian part of the Austrian Empire. During his childhood his family moved to Maplewood, New Jersey, where he attended Columbia High School, graduating in 1949.
Ehrlich earned a bachelor's degree in zoology from the University of Pennsylvania in 1953, an M.A. from the University of Kansas in 1955, and a Ph.D. from the University of Kansas in 1957, supervised by the prominent bee researcher Charles Duncan Michener (the title of his dissertation: "The Morphology, Phylogeny and Higher Classification of the Butterflies (Lepidoptera: Papilionoidea)"). During his studies he participated with surveys of insects in the areas of the Bering Sea and Canadian Arctic, and then with a National Institutes of Health fellowship, investigated the genetics and behavior of parasitic mites. In 1959 he joined the faculty at Stanford University, being promoted to professor of biology in 1966. By training he is an entomologist specializing in Lepidoptera (butterflies); he published a major paper about the evolution of plants and insects.
He was appointed to the Bing Professorship in 1977.
He is president of the Center for Conservation Biology at Stanford University. He is a fellow of the American Association for the Advancement of Science, the United States National Academy of Sciences, the American Academy of Arts and Sciences and the American Philosophical Society.
Paul R. Ehrlich