He into a well in Italy 130,000 years ago, couldn’t get out, and starved to death. And he had buck teeth!
Researchers at the Max Planck Institute for Evolutionary Anthropology in Germany analyzed the genetic data of 112,338 people of British ancestry who have Neanderthal DNA to conduct a study on the link between Neanderthal DNA and humans’ physical characteristics. Having access to a large cohort of study participants from the UK Biobank proved important, since there just isn’t much Neanderthal DNA floating around. (People of European and Asian descent get anywhere from 1â€“4 percent of their genes from Neanderthals, thanks to interbreeding thousands of years ago.)
Prior research has found that the ancient hominids may have influenced a variety of disease-related traits in humans. For instance, the presence of Neanderthal DNA is associated with the increased sensitivity to certain allergens and a higher risk for nicotine addiction. But in the new study, the researchers focused on nondisease phenotypes â€” the observable physical characteristics of an organism â€” in modern humans.
With the help of questionnaires given through UK Biobank, the researchers determined that the propensity to smoke and loneliness are associated with Neanderthal DNA. They also found that some Neanderthal alleles (variant forms of genes) contributed to lighter skin and hair tones in modern humans, while others contributed to darker tones. But breaking down the study’s results isn’t as easy as pointing to a certain shade of skin and linking it to Neanderthal DNA. Multiple alleles influence skin and hair color, and Neanderthals might’ve had a large range of skin and hair tones based on different pieces of genetic material, just like modern humans.
The researchers noted in the study that many of the Neanderthal-linked traits are related to sunlight exposure, including an allele that contributes to circadian rhythm and the tendency to be an “evening person.” In the study, non-African people living farther from the equator had higher frequencies of that allele. Indeed, Neanderthals had been living in northern environments with lower and more varying levels of ultraviolet radiation for thousands of years when modern humans came to the region from sunnier Africa.
So, if you stay up late and nap during the day? That might be the Neanderthal in you.
Research into human DNA has established that some homo sapiens, long, long ago, interbred with Neanderthals. (Hey! democrats had to come from somewhere.) But more recent research into the DNA of South Pacific islanders had found ancestry from Neanderthals and Denisovians and from a previously unknown third hominid group.
Islanders in the Pacific Ocean may be may be carrying traces of a long lost human species locked up in their DNA.
Today, modern humans inherit a small chunk of our genes from Neanderthals, with evidence that some of us carry the genetic remnants of a lesser known sister group, called the Denisovans.
But genetic analysis of people living in modern Melanesia suggests they carry traces of a third, as yet unidentified prehistoric relative distinct from the others.
The island groups of Melanesia â€“ which includes Papua New Guinea, Fiji and the Solomon Islands and others â€“ are geographically cut off by the Pacific Ocean, with their DNA providing a unique window into how human ancestors spread across the region.
The latest research, presented at a meeting of the American Society for Human Genetics in Vancouver, bolsters previous findings that there may be another strand to the story of modern humans, with multiple groups of prehistoric human interbreeding.
Read the whole thing.
Results show modern humans, Neandertals diverged 660,000 years ago
An international consortium of researchers reports in the Aug. 8 Cell that for the first time the complete sequence of mitochondrial DNA from a Neandertal has been deciphered. Comparison of the Neandertal sequence with mitochondrial sequences from modern humans confirms that the two groups belong to different branches of humankindâ€™s family tree, diverging 660,000 years ago.
That date is not statistically different from previous estimates of the split between humans and Neandertals, says Erik Trinkaus, a paleoanthropologist at Washington University in St. Louis. The sequence also doesnâ€™t reveal what happened to drive Neandertals to extinction, but it does clear up some discrepancies in earlier studies. …
At 16,565 bases long, the new sequence is the largest stretch of Neandertal DNA ever examined. The DNA was isolated from a 38,000-year-old bone found in a cave in Croatia.
â€œItâ€™s a nice accomplishment and the next important step toward completing the Neandertal genome,â€ says Stephan Schuster of Pennsylvania State University in University Park. Schuster is part of a group that is sequencing the genomes of the mammoth and other extinct animals, but was not involved in the current study. â€œItâ€™s a nice landmark on the way to saying what makes modern humans so special.â€
In order to know exactly how modern humans and Neandertals differ, scientists will need to examine DNA from the Neandertalâ€™s entire genome. The sequence reported in the new study was generated as part of a project to decode Neandertal DNA, but it contains information only about DNA from mitochondria.
Mitochondria are organelles that generate energy for a cell. Inside each mitochondrion is a circular piece of DNA that contains genes encoding some of the key proteins responsible for power generation. Mitochondria are passed down from mothers to their children. Scientists use variations in mitochondrial DNA as a molecular clock to tell how fast species are evolving.
Scientists have previously examined a short piece of Neandertal mitochondrial DNA known as the hypervariable region, but this new complete sequence helps clear up some ambiguities from studies comparing Neandertals and humans, says John Hawks, a biological anthropologist from the University of Wisconsinâ€“Madison.
Some modern humans have several changes in the hypervariable region that made it seem as if Neandertals are more closely related to modern humans than humans are to each other.
â€œComparing the complete mitochondrial DNA genomes of a Neandertal and many recent humans presents a very different picture,â€ Hawks says. â€œHumans are all more similar to each other, than any human is to a Neandertal. And in fact the Neandertal sequence is three or more times as different, on average, from us as we are from each other. This change from the earlier picture is a purely statistical one, but it makes a clearer picture.â€
Human and Neandertal mitochondrial DNAs differ at 206 positions out of the 16,565 examined, while modern humans differ at only about 100 positions when compared with each other.