Could you be part Neanderthal or even Denisovan. Find out in the debut of our new feature "Ask an Expert." What do you want to know? Submit your question today!
This is Sound Ideas. I’m Mike McCurdy, in the studio with Kevin Bersett, editor of ISU’s Redbird Scholar Magazine and the Ask the Expert column. And we’re talking about early man, early or different versions of humans. Kevin, thanks for joining us on Sound Ideas. We’ve both heard this kind of thing before…that humans today, you and I, have the DNA of ancient peoples. And we received a question?
KEVIN BERSETT: Yes. From Allie Beam who is a freshman at University High School in Normal.
ALLIE BEAM: I understand nearly everyone has Neanderthal DNA but are there other traces of species of early humans found in the human genome?
MIKE McCURDY: So what’s the answer? Am I part caveman or part Neanderthal?
BERSETT: Probably, but it’s not that simple. I turned to Fred Smith, Professor of Anthropology in the Department of Sociology and Anthropology. He said Neanderthal is probably not the only DNA lurking in the background. We might have Denisovan DNA.”
McCURDY: Denisovan – I’ve never heard of it.
BERSETT: Neither had I. Here’s what Dr. Smith had to say.
DR. FRED SMITH: They are a group of archaic humans that are different from modern humans genetically. They are more similar to Neanderthals but they're also not identical to Neanderthals. The interesting thing about Denisovans is that we don't know really what they look like anatomically. We now have two Denisovan genomes. These are based upon small fragments. One is a pinky finger bone. And there are a couple of teeth, but we don't really know who they are. There are archaic looking people in east Asia that aren't Neanderthals and so it's possible they are the Denisovans but we haven't made the connection between the anatomy and the genes like we have with the Neanderthals. Neanderthals are contributing somewhere between 3 to 8 percent to early modern humans and that translates to 1.6 to 2.1 percent to us today.
McCURDY: So if we know there's an average percentage of DNA of the pre-modern humans in people today someone must be doing some organized testing.
BERSETT: Yes. In fact, Dr. Smith had his own DNA tested.
SMITH: I did it through the National Geographic program. I was of course curious to see if I had Neanderthal heritage and how much. I'm almost entirely Scots-Irish, Northern European with a little Mediterranean thrown in but no native-American. And I was a little bit disappointed to find out i was only 1.8 percent Neanderthal. But I am 2.3 percent Denisovan so I guess that's some solace.
McCURDY: And this all helps support a theory that Dr. Smith proposed years ago.
BERSETT: Yes. For decades, it was argued that modern people moving from Africa totally replaced the archaic people, like the Neanderthals, rendering them extinct in the classic sense of the term. Dr. Smith was one of the minority of researchers who argued, based on morphology, that Neanderthals made relatively small contributions to the first modern populations in Europe, which he called the Assimilation Model.
SMITH: The Assimilation Model came out of my work with Neanderthals in the late 70s and early 80s and it really was a response to the increasing information that showed that modern humans fundamentally came out of Africa and initially the argument was they came totally out of Africa. But in my work, particularly on Croatian Neanderthals, I saw some evidence of Neanderthal contributions to early modern humans and I had trouble making that balance out with the genetic material. So I went with the morphological and suggested that at the time that the genetic evidence was probably not complete enough to determine this small but consistent Neanderthal and other archaic contribution.
McCURDY: And is DNA evidence causing more widespread acceptance of his theory?
BERSETT: Well, it was not at first…but thanks to evidence of Neanderthal and Denisovan contributions to the genome, it is now generally considered a very robust model to explain the beginning of people like us.
McCURDY: Kevin Bersett is the editor of Redbird Scholar magazine and editor of the magazine’s Ask and Expert column. Kevin, what will we talk about next time?
BERSETT: We’re going to talk about something everyone needs and something nearly everyone is thinking about, following revelations in Flint, Michigan. We’ll hear about some of the challenges faced by water providers in Bloomington and find out how Bloomington-Normal water stacks up with other communities.