For most of our evolutionary history — for most of the time anatomically modern humans have been on Earth — we've shared the planet with other species of humans. It's only been in the last 30,000 years, the mere blink of an evolutionary eye, that modern humans have occupied the planet as the sole representative of the hominin lineage.
But we carry evidence of these other species with us.
Lurking within our genome are traces of genetic material from a variety of ancient humans that no longer exist. These traces reveal a long history of intermingling, as our direct ancestors encountered — and mated with — archaic humans. As we use increasingly complex technologies to study these genetic connections, we are learning not only about these extinct humans but also about the larger picture of how we evolved as a species.
Joshua Akey, a professor in the
Lewis-Sigler Institute for Integrative Genomics, is spearheading efforts to understand this larger picture. He calls his research method genetic archaeology, and it's transforming how we're learning about our past. "We can excavate different types of humans not from dirt and fossils but directly from DNA," he said.
© Illustration by Michael Francis ReaganJoshua Akey, a professor in the Lewis-Sigler Institute for Integrative Genomics, uses a research method he calls genetic archaeology to transform how we’re learning about our past. Fossil evidence illustrates the spread of two long-extinct hominin species, Neanderthals and Denisovans. Modern humans carry genes from these species, indicating that our direct ancestors encountered and mated with archaic humans.
Combining his expertise in biology and Darwinian evolution with computational and statistical methods, Akey studies the genetic connections between modern humans and two species of extinct hominins: Neanderthals, the classical "cave men" of paleoanthropology; and Denisovans, a recently discovered archaic human. Akey's research divulges a complex history of the intermixing of early humans, indicative of several millennia of population movements across the globe.
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