A Visit to the Ornithology Collections
Evolution: A Course for Educators
How are all of the species living on Earth today related? How does understanding evolutionary science contribute to our well-being? In this course, participants will learn about evolutionary relationships, population genetics, and natural and artificial selection. Participants will explore evolutionary science and learn how to integrate it into their classrooms.
Darwin's Second Great Idea - Adaptation via Natural Selection
You will learn about Darwin’s second breakthrough: that adaptation via natural selection is the basic mechanism of evolution. You’ll go behind the scenes with Dr. Cracraft to see how evolutionary biologists use the Museum’s collections. Lastly, you’ll choose a topic from the course and explain how to use it as empirical evidence that supports common ancestry and biological evolution.
Joel Cracraft, Ph.D.
Chair and Lamont Curator
Division of Vertebrate Zoology
Welcome to the ornithology collection at the American Museum of Natural History.
We're standing in a very great hall used for exhibits,
but off to the side are thousands and thousands of birds.
The American Museum Ornithology Collection is the largest in the world.
So we have approximately 900,000
skins and skeletons, and fluid preserved specimens, and what we're
going to do here is look at some of my favorite birds, the Birds of Paradise.
So I've already talked about sexual selection.
And one of the great examples of it are the Birds of Paradise.
So this
is the Superb Bird of Paradise, and it's found on the island of New Guinea.
You remember I talked about sexual dimorphism, so in a
lot of sexually dimorphic birds the males are very gaudy.
And you can see reflection iridescence on the males.
And in Birds of Paradise most of the females
are brownish with a lot of streaking on them.
And the males are, look all black except for this iridescent breast shield.
And when they dance on the log, they also take this
cape and throw it up over their head, so you have this bright green, and
then you have this black, and there are very iridescent figures.
And they look like
two eyes there.
You don't even see the eyes because the eyes are, are dark brown.
And they dance around with the females.
Now in all Birds of Paradise, we know that they display with vocalization
and with elaborate dancing, but we don't know,
really, why a particular female chooses a particular male.
So in the Superb Bird of Paradise they
display single males on logs, females come in.
But let me now show you another Bird
of Paradise has, that has a different display.
In these birds, they form leks.
That is, the males are in tops of
trees, and they're displaying all around each other.
And the females then
come into these trees, and mating occurs, generally speaking,
with an older male that has had a lot of experience in display.
And you can see they have these very long trains of flank feathers.
And in some species they're bright red, in some species there's some blues.
And in this group, they have,
the males have this very maroon breast and
upper abdomen. And then they have this spectacular green
not so iridescent shield in front of their throat.
And when they display, they, they, they turn
on the perch underneath like this, and then they
shake these flank feathers to the females as if to say, look
this is really kind of neat and you should pay attention to me.
And then do a lot of movement, a lot of shaking a lot of movement.
But there, it's a very kind, a different display
in, in this group of birds, and they're quite spectacular.
So th-, these are ways in
which an evolutionary biologist studies these collections.
We study the geographic variation that we see in all these individuals.
But many other people make use of these collections, for instance
we can do an awful lot of genetics with these collections.
But now people can take feathers, they can ask questions.
What were they feeding on, because as
feathers grow, they incorporate the biochemical signatures
of food.
And we have many investigators coming into this collection wanting to look at
feathers and look at the biochemistry of feathers in order to see whether,
say, during a period of global change that the birds were feeding on
the same thing 20 or 30 years ago that they're feeding on today.
So there's many, many uses for collections such as this.
And the uses just keep growing, year by year by year, with all new
kinds of methods for, for analyzing material like these birds.
And they're just a, a treasure that will
just keep being used for decades into the future.