Where did we come from? For anthropologists like Milford Wolpoff of the University of Michigan, that question provokes contentious scientific debate. One side believes Homo sapiens descended from a single female "Eve" whose progeny spread around the globe, replacing more archaic species, some 100,000 years ago. Wolpoff and others take the opposing view that humanity emerged as much as 2 million years ago in many places as people colonized the world and gradually evolved to their modern state. Wolpoff discussed the lingering debate with Discover associate editor Kathy A. Svitil.

What will settle the debate?
I think the evidence, both anatomic and genetic, has been there a long time. It tells us that the Eve theory is wrong. For instance, various skeletal features show continuity of form, from ancient to modern, in several parts of the world. The Eve theory predicts abrupt change.

Some people have interpreted your theory to mean that certain races are more evolved than others. How do you respond to that?
I get deeply upset to think that I've ever contributed to racism, even if it is only by people misquoting me. What people are generally quoting is the idea that modern humans arose in one place and then went around interbreeding with everyone else, which opens itself up to a racist interpretation. What I've actually said is that modern features developed everywhere and spread everywhere because they were helpful.

How has that understanding affected your views on race?
There are no pure races. Our populations are thoroughly mixed, and we are related to everybody. The idea that one race could be better at something than another race makes no sense. If a trait is important, everyone has it.

Can we ever reconstruct a perfect human family tree?
No, because the tree model doesn't fit population history well. Trees are things that branch and branch and branch, but populations don't just divide— they also merge back together. Just look at America. A network of lines that merge together as well as lines that divide apart is a much better model. But we won't get a perfect network either. There is too much we will never know.

How do you feel about the creationists who use such uncertainties to attack evolution?
I'm more upset about the racism. Creationism isn't science. It is a belief about religion, a belief about origins. The things that creationists say— that all life was created by God in six days, for example— are scientifically wrong, but I have no quarrel with them as pieces of religion.

Does your research suggest evolution favors intelligence?
No. It has favored our intelligence, but humans are the great exception. You could never make a case that intelligence is the best strategy. Over the past 20 million years, monkeys have been much more successful than apes, even though apes have bigger brains and are more intelligent by any measure.

Where do you think human evolution will go from here?
The real question is where our culture and our technology will go from here. I think people will soon be manipulating the genome so that we'll be able to decide what we want our kids to be like. I don't just mean their hair color but whether they play the violin or not, whether they have two arms or four, whether they breathe with lungs or with gills. The evolution of our species is limited only by the bounds of our imagination.