As a student, I was supported with a National Institutes of Dental Research Traineeship, so I was expected to do something in the area of teeth. And since teeth are the things that preserve the best in the fossil record, it was appropriate to do this sort of study. I did a long, very boring thesis on chimpanzee teeth. I traveled all over Europe and looked at museum collections, and published — or produced — a very thick thesis on all the detail of chimpanzee teeth. And that prepared me for understanding the teeth of our human ancestors better than anything else I could have done. During the course of my research for my Ph.D., Clark was working in Ethiopia, and he was going to study some fossils of human ancestors in South Africa. He was particularly interested in what he could learn from the anatomy of the teeth and he asked me if I had any ideas of things that he should look for. I spent several hours with him, and he said, “Why don’t you come with me on this trip?” Of course, I was thrilled to go to Africa to see the original fossils of this terrible tongue-twister, Australopithecus. And then I said, “Since I’m going to South Africa, and flying through Nairobi, why can’t I come up and visit your expedition?” He gave me that break. He said, “Why don’t you come up and visit us. Why don’t you come up and see what it’s like to be in the field, finding these fossils.” That was the break that all of us dreamed of as students. That was in 1970, and since then I have worked on and off throughout the Great Rift Valley of East Africa.