If you were to encounter humans from 300,000 years ago, you might be struck by how much they look like humans in 2018. Anatomically modern and large-brained, with faces and teeth not dissimilar to our own, these early Homo sapienswent to war, formed relationships, and created tools, just like us. There’s still plenty to learn about our direct evolutionary ancestors, but this year, thanks to the widespread use of genomic sequencing, scientists gave us an unprecedented glimpse into how humans came to be. Here, Inverse lists everything we’ve learned about human evolution in the past year.
While we are the only hominids to walk the Earth today, this year genomic evidence proved that the DNA of some people contains traces of Paleolithic trysts between humans and other Homo species, like the Neanderthals and the Denisovans. A decade ago, scientists would have been extremely skeptical. University of Buffalo evolutionary anthropologist Omer Gokcumen, Ph.D. tells Inverse that it’s only in the past five years that scientists have been able to confirm that early Sapiens didn’t only hang out with other Sapiens.
“You can think of the world 100,000 years ago like a Lord of the Rings world, where different, pretty smart human-like creatures are roaming,” Gokcumen says, explaining that this situation is called interaction dynamism. “One of them would be our ancestors in Africa, but there would also be other species like Neanderthals, that we could tell were different — but not different enough to not interbreed and produce fertile offspring.”
This year, academics including Gokcumen published an extensive amount of research filling in the details of this Tolkien-esque world, furthering our understanding of how our minds, bodies, and behavior came to be. Learning what it means to be human, it seems, means learning about really old humans.
5. Neanderthal Brains Grew At a Slower Pace Than Human Brains
In a paper published in Science in September, an international team of scientists reported that they found 13 ancient Neanderthal skeletons in a 49,000-year old cave in northern Spain. To the astonishment of the researchers, one of the specimens, which they named El Sidron, was a nearly complete specimen that belonged to a boy who died when he was almost eight years old.
El Sidron’s teeth and endocranial features suggested that his brain growth wasn’t done by the time of his death, giving away his age. A human brain is essentially grown to its full size by the time a person is six, but El Sidron’s brain was still growing at a period when the brains of his peers had long since stopped. This extended period of brain growth, the study authors hypothesize, suggest Neanderthal children spent more time acquiring cognitive skills than human children.
But perhaps the most marvelous revelation from this study was the fact that, barring brain growth, Neanderthal children were much like human children in terms of physical growth and maturation, reducing the gap between us and our not-so-distant cousins.