Genealogy has developed an enthusiastic following due to family tree sleuthers knack for uncovering mysteries in their heritage. The thrill of the search can be driven by hopes of unearthing exciting or powerful distant relatives. If you go far enough back though, the unexpected connections may not be just to royalty, but to other species.
It’s true – you probably have a little Neanderthal in you.
Species are known to interbreed in nature and ancient humans were no exception. Tens of thousands of years ago Eurasian Homo sapiens mated with the closely related Neanderthals and some of their genes have stuck around in modern humans. In fact, people who trace their roots back to Europe and Asia have on average 1 – 3% Neanderthal genes.
Neanderthals showed up on the prehistoric scene some 200 thousand years ago and lived throughout Europe and Western Asia. Modern humans traveled out of Africa through the Middle East, where Neanderthals also lived, 50,000 to 60,000 years ago. It was previously thought that modern human’s Neanderthal genes came from interbreeding during this period.
However, modern humans also lived among Neanderthals in Europe starting around 45,000 years ago. The two closely related species coexisted in this geographical range for about 5,000 years before the Neanderthal’s ultimate extinction. Those shared millennia provided many opportunities for interbreeding, but until recently there hasn’t been evidence to support this possibility.
An international team of researchers found a surprisingly large amount of Neanderthal DNA in an ancient human jawbone. The mandible in question was found by cavers in Romania and has been undergoing research since 2002. Radiocarbon dating puts the age of the jaw and other skeletal remains at roughly 35,000 years old – which would catch the tail end of Neanderthal cohabitation in Europe. This specimen has more Neanderthal DNA – between five and 11% – than any previously analyzed human.
The size of Neanderthal DNA sequences in the human jaw gives a clue as to how many generations ago the Neanderthal interbreeding occurred. Every generation offspring inherit half of their DNA from each parent. This maternal and paternal DNA gets chopped up a bit, and mixed and matched every generation. Practically, this means that any one length of DNA inherited from a single relative gets a little shorter every generation as it’s mixed with a new partner’s DNA.
Based on the relatively large stretch of Neanderthal DNA in the Romanian jawbone, scientists conclude that the Neanderthal relative could have been as close as a great-great-grand parent. This is the closest human link to Neanderthals that has been discovered to date.
Having Neanderthal DNA is nothing to be embarrassed about. Contrary to their dullard stereotype, Neanderthals actually had bigger brains than modern humans. This mass of grey matter goes to explain some of the fascinating artifacts they left behind. The fossil record indicates that Neanderthals made stone tools, cooked vegetables, and even purposefully buried their dead. Indeed, our evolutionary relatives were far from simpletons.
If your family traces its origins back to Eurasia, wear your Neanderthal heritage with pride.
The Romanian jawbone data was published in the highly prestigious journal Nature on June 22nd with the title “An early modern human from Romania with a recent Neanderthal ancestor”. The abstract can be read here: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14558.html