How Will Humans Evolve?
Donald Johanson is an American paleoanthropologist and the founder of the Institute of Human Origins. He went on his first exploratory expedition to Ethiopia in 1972, and the following year completed his PhD and began teaching at Case Western Reserve University. In 1974 he discovered AL 288-1, a partial skeleton of a female australopithecine who soon became world-renowned as "Lucy." In 1975 he and his team found a major collection of fossils, known as "The First Family," at a single site. In 1976, more hominid fossils were discovered, along with stone tools which, at 2.5 million years, were the oldest in the world. In 1978, he and his colleague, Tim White, named the species he had discovered Australopithecus afarensis.
In 1981, Johanson founded the Institute of Human Origins, a non-profit research institution devoted to the study of prehistory. He is the author of several books including, most recently, "Lucy's Legacy: The Quest for Human Origins" (with Kate Wong, Harmony Books, 2009).
Question: How do you assess the impact of human culture on our species’ evolution?
Donald Johanson: Biological evolution as articulated of course by Darwin and Wallace in the 1800s explains and now with of course the great subject of genetics, which really helps us understand how features are inherited and altered and so on. Evolution explains our biological evolution, but human beings are very unique creatures. As the Dobzhansky said all animals are unique; humans are the uniquest. And that uniqueness of being human, language, art, culture, our dependency on culture for survival, comes from the combination of traditional biological evolution. We look biologically very different from say from Lucy, from Australopithecus, from homo erectus, from all these different species, so biologically we’ve evolved, but we are culturally just light years away from Neanderthals, light years away from say early homo sapiens, so that biological evolution is culture is genetically buried very slow. We still think I think in many ways with a hunter, gatherer mentality, but cultural evolution as we know, I mean Paul Lazer, the man who is my mentor, he was born in the late 1800s. Imagine what he saw in terms of cultural evolution from the time he was a young teenager to the time when he died in his late ‘80s, so the cultural evolution has this sort of ratchet aspect to it that once you make a significant leap to say putting information on a little chip that causes a giant leap in the way we process information, store information, manipulate information, so that we are a product of both biological and cultural evolution, which is an extraordinarily powerful combination. The synergy of those two together is like no other creature we have ever seen.
Question: What modern cultural or environmental changes could affect the future of human evolution?
Donald Johanson: Well, trying to predict the future biologically and evolutionary as to where we’re going is a very difficult thing, but one thing that we are seeing is that the species, homo sapiens, which is a global species and that there are distinctive differences between different populations. Some populations have a lighter skin. Some populations have darker skin and some people the epicanthic eye fold and others don’t, but there is more of a homogenization of people today. Those distinctive features that we see in different populations have arisen because those populations had been isolated. Well, today the species is interbreeding globally, so there probably is going to be more of a homogenization of some of the biological features as well as some of the features that you mentioned, such as lactose deficiency and so on that may ultimately disappear, but I think there will be more of a homogenization of the species over time with increased spread of genes between disparate populations.
Recorded on March 19, 2010
Interviewed by Austin Allen
As globalization continues and the spread of genes between disparate populations increases, our biological features are likely to become more homogeneous. Culture, meanwhile, will continue to evolve at an explosive rate.