Mating With Neanderthals and Other Joys of Prehistoric Life

One of the great adventures in all of history is the story of how we and other humans evolved. Evolution is more jagged and irregular than we think. Seventy-five thousand years ago, at least four other species of humans, in addition to us, were roaming the planet, struggling to survive. That included the “hobbits” of Indonesia. Sometimes these species mated with one another, changing our DNA forever. But why did we Homo sapiens survive, when the rest didn’t?

An artists conception of a Neanderthal man (Drawing by Frank Harris)

Around the time Last Ape Standing was published, I was asked to write an article in the Wall Street Journal. The Internet was in an uproar because Harvard molecular biologist George Church was quoted in Der Spiegel as saying that eventually an “adventurous female human” will be needed to act as a surrogate mother for the first Neanderthal baby. Advances in genetic engineering were moving that fast. He also speculated that this might cause “a kind of Neanderthal culture” to arise.

This only underscores how rapidly our view of our past and the effects it may have on our future are changing. Just a few years ago human evolution was seen as a nice steady climb up the Darwinian ladder from hunched primate to upright walking Homo sapiens (we’ve all seen the iconic image. At the end a shiny, modern human would emerge. That turns out to be all wrong. Not only wasn’t there a solitary line of proto-humans from whom we, and we alone, evolved, but there were multiple species of humans with a wide range of pedigrees roaming Africa’s savannas going back millions of years (28 by the current count). We know this because in the past few years there have been a string of discoveries about our past that have rocked the world of human evolution and completely rearranged our view of who we are and how we got here.

The first of these discoveries came in 2003 when archeologists found that a Lilliputian species of human, but not a modern Homo sapiens, had been living on the Indonesian Island of Flores as recently as 13,000 years ago. They were dubbed Homo floresiensis, or the “hobbit.” That a creature could hunt, control fire, may have spoken some kind of language, and done it all with a brain as diminutive as a chimpanzee’s floored and excited paleoanthropologists. The consensus these days is that they evolved from Homo erectus, an earlier branch of humans that had migrated to the Pacific as long as a million years ago, and then departed the planet tens of thousands of years earlier.

The Immense Cave Where the Remains of the Homo Floresiensis People Were Found  (Photo Wikimedia Commons) A mystery still confounding anthropologists.

A second big discovery came in 2010 when anthologists at the Max Planck Institute completed a deeper review of the Neanderthal genome. They were checking for evidence that Neanderthals, and our director ancestors, the Cro-Magnon people, had mated after migrating to Europe around 50,000 years ago. Given what happens in bars and boudoirs throughout the world on your typical weekend, it would seem that mating between two humans even if they weren’t the same species would be obvious, but science had long struggled with the idea that separate species would or could mate.

The genomic review proved that love, or lust, had won out. Based on the sources of the genetic information, the resolute scientists at Max Planck found that most of the human race with roots from Europe to the islands of Southeast Asia have at least a little Neanderthal running through their veins. A separate test later revealed that aging rock star Ozzie Osborne was also carrying around Neanderthal genes in his DNA, but the world didn’t seem much surprised by that. In any case another foundation of old thinking had toppled: interspecies sex, once an heretical thought, was a reality. That raised another question: if Neanderthals and Cro-Magnon people had mated, had other species too?

The answer to that question came not long afterwards in 2011 when the scientific team at Max Planck once again pulled off a remarkable scientific feat. Working with nothing more than a finger bone fragment from a juvenile girl, the team managed to ascertain the fossil belonged to an entirely new species of human, neither Homo sapiens, Hobbit nor Neanderthal, but a people who walked the earth as recently as 40,000 years ago. Scientists unofficially dubbed them Denisovans. Not only that but based on other fossils and detritus unearthed in the cave, the Denisovan DNA revealed that these people had mated with both Neanderthals and our direct ancestors. This meant indicated that inter-species marriage among humans might be universal.

Scientists still have yet to find out what Denisovan’s look like because they have not found anything but the tiniest fragments of their bodies - the finger-bone, a tooth and toe bone.

You would think all of this would be plenty to keep paleoanthropologists busy for years, and it is Nevertheless, another shattering discovery surface a few years back when scientists in Australia and China put together the broken skull bones of several creatures found in two different cave locations in southern China. The odd thing about the specimens was they combined archaic human features with modern ones. But far more remarkable was the discovery that the species that had been living north of Vietnam as recently as 11,500 years ago, just as Homo sapiens themselves were on the verge of making one of the most important advances in human history – agriculture.

Human remains from the Red Deer Cave people (upper left, newly described thigh bone; upper right, skull bones and tooth), the Maludong fossil site (bottom left) and an artist’s reconstruction of a Red Deer Cave man. Credit: Darren Curnoe, Ji Xueping & Peter Schouten.

This easily made them the most recent species to co-exist with our direct ancestors; three millennia closer than the last known Hobbit and a good 14,000 years closer than the Neanderthal. Not everyone agrees that the Red Deer Cave People (temporarily named for where they lived and the animal they hunted) are a separate human species. They could be, or they could be a hybrid result of interspecies breeding among Denisovans and nearby Homo sapiens, or even descended from a combination of Denisovans and Homo erectus. It’s simply too early to tell, but the Max Planck team is busy analyzing the DNA right now. More will almost certainly be forthcoming.

You can read more about the evolution and lives of Neanderthals and the other species in Last Ape Standing. Click to view either e-book or specially signed hardback or paperback.