Dr. Mary-Claire King

They had the same length.

There were occasional exceptions, so I knew I wasn't completely hopeless.

But mostly they were just the same.

Of course.

Of course.

Naturally.

Right.

So I took all of these, you know, gels and photographs and all that.

And I said, Alan, you know, I know you set me up with the world's most straightforward experiments and Igor Giblet's book is totally terrific.

But look, they're all the same.

And he kind of looked at me and he smiled this very Alan Wilson-like smile.

And he said, has it ever occurred to you that you've got it right?

And I said, but here am I looking at a picture of a chimpanzee.

I said, we can't have it right.

And he said, no, let's think it through.

And that was the conversation that

that led to our formulating this idea that the clear differences between humans and chimpanzees in morphology, that is in length of limbs, in anatomy, in body structure, in ways of life, we're not denying those.

Obviously, they are dramatically different, and they are the reason that taxonomists working with the species at that level had put humans and chimpanzees into different families.

That level of evolution could be completely consistent with the very, very minimal number of differences that we were seeing between humans and chimpanzees at the level of protein sequences if, in fact, those dramatic differences in anatomy and morphology and ways of life were due not to changes in sequences of proteins but to changes in the timing

of the expression of those proteins and the spatial distribution of the tissues in which those proteins were expressed.