Archaeological News

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Posts tagged "genetics"

The continuing debate regarding the origins of people inhabiting ancient Mesopotamia during the region’s long history led the authors of a new report published in the Open Access journal PLoS ONE to attempt an isolation and analysis of mtDNA sequences from the area.

Ancient DNA methodology was applied to analyse sequences extracted from freshly unearthed remains (teeth) of 4 individuals deeply deposited in the slightly alkaline soil of Tell Ashara (ancient Terqa) and Tell Masaikh (ancient Kar-Assurnasirpal) – Syrian archaeological sites, both in the middle Euphrates valley.

Research was also carried out by another team (Sołtysiak et al 2013) examining fifty-nine dental non-metric traits on a sample of teeth from 350 human skeletons excavated at three sites in the lower middle Euphrates valley. Read more.

The first humans left Africa some 200,000 years ago, dispersing to populate the rest of the world. But this was not a one-way trip: some people came back. Scientists say that they have traced a reverse migration that, in two steps, carried genes from the rest of the world back to southern Africa, long before European colonizers arrived.

The findings are part of a flurry of research enabled by better tools to survey African genomes. For the first time, population geneticists can examine the complex history of human migration in Africa effectively, a field long dominated by the analysis of bones, artefacts and languages.

“Up until now this was mostly done based on linguistics and archaeology, and now we can use genetics to test ideas,” says Carina Schlebusch, a geneticist at Uppsala University in Sweden. “It’s a really exciting time for African genetics.” Read more.

The caste system in South Asia — which rigidly separates people into high, middle and lower classes — may have been firmly entrenched by about 2,000 years ago, a new genetic analysis suggests.

Researchers found that people from different genetic populations in India began mixing about 4,200 years ago, but the mingling stopped around 1,900 years ago, according to the analysis published today (Aug. 8) in the American Journal of Human Genetics.

Combining this new genetic information with ancient texts, the results suggest that class distinctions emerged 3,000 to 3,500 years ago, and caste divisions became strict roughly two millennia ago. Read more.

Mitochondrial Eve and Y-chromosomal Adam—two individuals who passed down a portion of their genomes to the vast expanse of humanity—are known as our most recent common ancestors, or MRCAs. But many aspects of their existence, including when they lived, are shrouded in mystery.

Now, a study led by the Stanford University School of Medicine indicates the two roughly overlapped during evolutionary time: from between 120,000 to 156,000 years ago for the man, and between 99,000 and 148,000 years ago for the woman.

"Previous research has indicated that the male MRCA lived much more recently than the female MRCA," said Carlos Bustamante, PhD, a professor of genetics at Stanford. "But now our research shows that there’s no discrepancy." Previous estimates for the male MRCA ranged from between 50,000 to 115,000 years ago. Read more.

Using genetic analyses, scientists have discovered that Northern European populations — including British, Scandinavians, French, and some Eastern Europeans — descend from a mixture of two very different ancestral populations, and one of these populations is related to Native Americans. This discovery helps fill gaps in scientific understanding of both Native American and Northern European ancestry, while providing an explanation for some genetic similarities among what would otherwise seem to be very divergent groups.

This research was published in the November 2012 issue of the Genetics Society of America’s journal Genetics. Read more.

No Thanksgiving dinner is complete without a succulent roasted turkey. The U.S. Department of Agriculture estimates that consumers cook and eat more than 45 million turkeys every Thanksgiving. Very few Americans, however, know much about the difference between their gravy-smothered poultry and the poultry that earlier generations of Americans ate to celebrate the holiday.

"Ancient turkeys weren’t your Butterball," said Rob Fleischer, head of the Smithsonian Conservation Biology Institute’s Center for Conservation and Evolutionary Genetics. "We set out to compare the genetic diversity of the domestic turkeys we eat today with that of the ancestral wild turkey from South Mexico. Some of what we found surprised us." Read more.

Cross-breeding of dogs over thousands of years has made it extremely difficult to trace the ancient genetic roots of today’s pets, according to a new study led by Durham University. An international team of scientists analyzed data of the genetic make-up of modern-day dogs, alongside an assessment of the global archaeological record of dog remains, and found that modern breeds genetically have little in common with their ancient ancestors.

Dogs were the first domesticated animals and the researchers say their findings will ultimately lead to greater understanding of dogs’ origins and the development of early human civilization.

Although many modern breeds look like those depicted in ancient texts or in Egyptian pyramids, cross-breeding across thousands of years has meant that it is not accurate to label any modern breeds as “ancient,” the researchers said. Read more.

Does evolution have a soft spot for blondes? About 5–10% of people from Melanesia, a group of islands northeast of Australia, have naturally blonde hair — the highest prevalence outside Europe. Yet people from the region have the darkest skin pigmentation outside Africa.

Now, a study of people from the Solomon Islands in Melanesia shows that they evolved the striking blonde trait independently of people in Europe. This refutes the possibility that blonde hair was introduced by colonial Europeans, says Carlos Bustamante, a geneticist at Stanford University School of Medicine in Stanford, California, and a senior co-author on the study, which is published today in Science. ”Blonde hair has clearly evolved twice,” he says. Read more.