A Bunch of Neanderthals by Angela Rieck

A friend of mine recently discovered that she has a trace amount of Neanderthal DNA. It is estimated that 2% of Eurasians and 4% of East Asians have Neanderthal DNA. 

While Neanderthals became extinct, scientists now know that there was interbreeding between Homo Sapiens and Neanderthals. Some DNA from Neanderthals also includes Homo Sapien DNA, which suggests that interbreeding went both ways. 

There is another group of humanoids that interbred with Homo Sapiens, the Denisovans. Three to fifteen percent of Pacific Islanders, including the Philippines, have Denisovan DNA.

Around 300,000 years ago there were nine known Homo species in the continents of Africa, Europe, and Asia. Because of the interbreeding we know that Neanderthal and Denisovans overlapped with Homo Sapiens. Homo Sapiens began in Africa and eventually migrated to the European continent, but DNA tests of modern-day Africans show that a tiny percent have Neanderthal genes suggesting that it was not a one-way migration. 

Neanderthals are believed to have become extinct around 40,000 years ago. There was a 5,000-year period when Homo Sapiens and Neanderthals overlapped. Neanderthal remains have been found exclusively in Europe. Homo Sapien bones in Europe are dated approximately 47,000 years ago. 

Denisovans are only a recent discovery; they were discovered in 2010 in a cave in Russia. Based on butchered animal bones and stone tools used to remove animal hides, they were likely hunter-gatherers. They lasted later than the Neanderthals (approximately 35,000 years ago), which could explain their higher percentages. 

So, do scientists know how and why Homo Sapiens won the game of life? 

Of course, they cannot know, but they have some theories. First, there were not many Neanderthals. (Only a few small bone fragments of Denisovans have been found, so little is known about that species.) One theory is that Homo Sapiens had bigger brains and used more tools than Neanderthals. Neanderthal communities were smaller than Homo sapiens communities, and scientists suspect that there was inbreeding within their group. Due to this inbreeding, Neanderthals may have been more susceptible to disease and other pathogens. The fact that Homo Sapiens would have collaborated more and lived in larger groups is another possible reason for their survival. 

Another theory is that the Neanderthals may have been wiped out by the Ice Age, and Homo Sapiens, despite coming from Africa, were somehow more adaptable to climate change. With the Ice Age came more competition for scarce resources. Thus, wars and violence over these limited resources is also a possibility. Finally, some scientists believe that perhaps a lot of interbreeding with Homo Sapiens may have effectively replaced Neanderthals with Homo Sapiens. It is likely to be a combination of all of these factors.

So, the bottom line is that somehow our species survived while others didn’t. But they didn’t completely go away, they are in DNA. And this ancient DNA may hold some secrets; already scientists have discovered that Denisovan DNA has genes that enable people to be successful in high altitudes. Given how difficult life was back then, it is perhaps a good thing to have this ancient DNA.

Homo Sapiens won in a “survival of the fittest” scenario. However, given our current political climate, I am now wondering about if the fittest did survive.

Angela Rieck, a Caroline County native, received her PhD in Mathematical Psychology from the University of Maryland and worked as a scientist at Bell Labs, and other high-tech companies in New Jersey before retiring as a corporate executive. Angela and her dogs divide their time between St Michaels and Key West Florida. Her daughter lives and works in New York City.