A pair of studies published by Cell Press on February 14th in the journal Cell sheds new light on genetic variation that may have played a key role in human evolution. The study researchers used an animal model to study a gene variant that could have helped humans adapt to humid climates, and they used whole-genome sequence data to identify hundreds of gene variants that potentially helped humans adapt to changing environmental conditions over time. The findings provide a road map for understanding human biological history as well as modern-day variability.
"There is an archaeological record hidden in our DNA that can help point us to the traits that have been critical in human survival, such as resistance to infectious diseases and new abilities to respond to different environments," says senior study author Pardis Sabeti of Harvard University and the Broad Institute. "The two studies have uncovered two intriguing human adaptive traits and demonstrate the ability to go from an unbiased genome scan to a novel hypothesis of human evolution."
Sabeti and her team found that a previously reported variant of the EDAR gene, which arose in central China about 30,000 years ago, increased the number of sweat glands in genetically modified mice and had other effects not previously reported in humans; their discovery demonstrates that animal models can be used to study the biological changes expected to result from human genetic variation. This gene variant was also associated with an increase in the number of sweat glands in a present-day Han Chinese population. By enhancing sweating, this EDAR variant could have helped humans adapt to humid climates that may have existed in China 30,000 years ago.
In the accompanying study, the researchers used data from the 1000 Genomes Project to analyze DNA sequence variations across the entire genome. They identified hundreds of gene variants that potentially contributed to human evolutionary adaptation. One of these variants, a mutation in the TLR5 gene, changed the immune responses of cells exposed to bacterial proteins, suggesting that this variant could confer a fitness advantage by protecting against bacterial infections. The comprehensive list of possible adaptive mutations driving recent human evolution provides the groundwork for future studies.
"These two studies are the product of work done in this area for over a decade but can only now be made possible with the major breakthroughs in genomic technology," Sabeti says. "I am struck by the ability of genomics to uncover the secrets of human history."
Cell Press: http://www.cellpress.com
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Physicist Danielle Bassett has been awarded a MacArthur Fellowship based on her work studying the human brain. She talks with Melissa Block about the advances it may lead to.
A team of researchers are using multispectral imaging to uncover hidden text on a 1491 Martellus map, one of the most important maps in history. Lead researcher Chet Van Duzer thinks the discoveries will allow historians and scholars to see just how the map influenced cartography in its time.
Genetic evidence from ancient humans and modern people suggests that travelers from northern Eurasia moved south several thousand years ago. They stuck around to have kids with early European farmers.
Kissing bugs, which can spread Chagas disease, turned up positive for human blood meals in caves in Guatemala and Belize
Epilepsy can be very disruptive and debilitating, but can it also spur creativity? If treatments suppress comedic inspiration and this directly affects your job, is it worth it?
Rising temperatures and a more acidic ocean may spell trouble for the Chesapeake Bay's iconic crabs, oysters and fish
Huge specimen caught in Antarctic waters by New Zealand fishing crew is one of few ever examined
Lonesome George, the worlds most famous tortoise, goes on display at the American Museum of Natural History.
Oxytricha trifallax lives in ponds all over the world. Under an electron microscope it looks like a football adorned with tassels. The tiny fringes are the cilia it uses to move around and gobble up algae. What makes Oxytricha unusual, however, is the crazy things it does with its DNA.
A Japanese woman with macular degeneration is the first person to be treated with induced pluripotent stem cells, made from her own skin