In 1991, researchers led by archaeologist and anthropologist David Lordkipanidze unearthed a primitive hominid jaw in Dmanisi, Georgia. They estimated its age at approximately 1.77 million years old, almost 800,000 years before our early ancestors were thought to have migrated out of Africa. Since then, a wealth of similar fossils and primitive tools have been uncovered at the site, surprising the scientific community and shedding new light on how man first spread throughout the world.
The Field Museum, in collaboration with The Leakey Foundation, will host Lordkipanidze for a special talk on April 9. We spoke with him for a preview.
What is special about the fossils found in Dmanisi, especially compared to other Homo erectus fossils found outside of Africa?
They are the first hominids out of Africa, dating from around 1.8 million years ago, and the most primitive.
It’s also important that, up to now, the anatomy of early Homo and even Homo erectus was almost exclusively known from skulls. Remains from the rest of the skeleton, called post-cranial elements, are rare and fragmented. Now we have post-cranial remains from at least four individuals from Dmanisi, and they are well preserved. They’re allowing us to learn more about the evolution of body constitution and locomotion in early Homo. It gives us a chance to estimate body mass and brain size.
Evidence has shown that Dmanisi people were small – around 1.5 meters tall. Their brains were smaller – around 600-750 cubic centimeters. In the case of classic Homo erectus, you have around 1000 cubic centimeters. So in this respect, they are closer to the genus Homo habilis (the predecessor to Homo erectus). At the same time, Dmanisi hominids had some progressive features. I would say that [they] walked and ran almost like modern humans.
It is, I would say, the largest collection of early Homo remains in the world. For the first time we can speak about population, not just isolated finds.
How are the fossils found at Dmanisi changing the way we think about early man’s migration out of Africa?
Before the Dmanisi finds, the theory was that humans left Africa when their bodies became larger, there was an increase in brain capacity, and they became real carnivores. [But] the Dmanisi hominids are the first representation of our genus outside of Africa. They represent the most primitive population of the species Homo erectus. This would suggest a Eurasian origin of Homo erectus.
Another scenario is that Homo erectus originated in Africa, and the Dmanisi hominids represent the first dispersal out of Africa. More and earlier hominid fossils are needed to support [either] hypothesis.
I’ve read that one jaw found at Dmanisi provided some hints about the early hominids’ social interactions. Would you tell me about that?
Unfortunately, we don’t have direct evidence for most behaviors of hominids. We can only guess and reconstruct.
But one skull does have indirect evidence of behavior. We found a skull with no teeth, and [could observe that the individual] went for a year with no teeth. And this was someone in a very harsh environment. We propose that the group was taking care of him or her, so maybe we can talk about [early indications of] compassion.
Lordkipanidze will speak about his work at a special event at the Field Museum in partnership with The Leakey Foundation on April 9, which is free with museum admission. For more information, call 415.561.4646 or visit the events section of The Field Museum’s website.