The discovery and analysis of an extremely rare African American Y chromosome pushes back the time of the most recent common ancestor for the Y chromosome lineage tree to 338,000 years ago. This time predates the age of the oldest known anatomically modern human fossils.
University of Arizona geneticists have discovered the oldest known genetic branch of the human Y chromosome — the hereditary factor determining male sex.
The new divergent lineage, which was found in an individual who submitted his DNA to Family Tree DNA, a company specializing in DNA analysis to trace family roots, branched from the Y chromosome tree before the first appearance of anatomically modern humans in the fossil record. 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.
Researchers have discovered a gene duplication related to the human brain that may have been responsible for adaptive evolutionary changes leading from ancient primate ancestors to modern humans. According to the scientists who participated in the study, two gene duplications occurred that were related to brain development, an aspect of change that was key to the emergence of ancestral and, ultimately, modern humans.
"There are approximately 30 genes that were selectively duplicated in humans," said Franck Polleux, a study participant and expert in brain development at The Scripps Research Institute. "These are some of our most recent genomic innovations."
Polleux and Evan Eichler, who is a genome scientist at the University of Washington, focused on a key gene known as SRGAP2. This gene was apparently duplicated at least twice over the past four million years, once about 3.5 million years ago and again about 2.5 million years ago. Read more.
TEMPE - The popular perception of archaeology is a team of dusty individuals in wide-brimmed hats unearthing treasures from a pharaoh’s tomb or an ancient collection of Native American artifacts.
Archaeology is that, but it is also a social science that utilizes information from other disciplines to inform and enhance archaeological data and to provide input to other sciences. Arizona State University Anthropology Professor Michael Smith explores the broadened scope of archaeology in the paper “Archaeology as a Social Science” published this week in Proceedings of the National Academy of Sciences. Gary M. Feinman of The Field Museum in Chicago, Robert D. Drennan of University of Pittsburgh, Timothy Earle of Northwestern University and Ian Morris of Stanford University are co-authors of the paper.
"A lot of people’s perceptions are based on classical archaeology (such as the study of ancient Greece or Rome), or on the latest tomb discovered or the biggest palace," says Smith, of ASU’s School of Human Evolution and Social Change. "Viewing archaeology as a social science advances how we interpret sites and how we do research." Read more.
Some 2250 years ago in Egypt, a man known today only as M1 struggled with a long, painful, progressive illness. A dull pain throbbed in his lower back, then spread to other parts of his body, making most movements a misery. When M1 finally succumbed to the mysterious ailment between the ages of 51 and 60, his family paid for him to be mummified so that he could be reborn and relish the pleasures of the afterworld.
Now an international research team has diagnosed what ailed M1: the oldest known case of prostate cancer in ancient Egypt and the second oldest case in the world. (The earliest diagnosis of prostate cancer came from the 2700-year-old skeleton of a Scythian king in Russia.) Moreover, the new study now in press in the International Journal of Paleopathology, suggests that earlier investigators may have underestimated the prevalence of cancer in ancient populations because high-resolution computerized tomography (CT) scanners capable of finding tumors measuring just 1 to 2 millimeters in diameter only became available in 2005. Read more.
For the first time, neutron images in 3 dimensions have been taken of rare archaeological artifacts here at ORNL. Bronze and brass artifacts excavated at the ancient city of Petra, in Jordan were recently imaged in 3 dimensions using neutrons at HFIR’s CG-1D Neutron Imaging instrument. The data that is now being analyzed will for the first time give eager archeologists and ancient historians significant, otherwise wholly inaccessible insight into the manufacturing and lives of cultures that once occupied settlements within the Roman Empire, Middle East, and Colonial-period New England.
The samples that were imaged in 3-D in August came from the collections of the Joukowsky Institute for Archaeology and the Ancient World at Brown University. They include an elaborate hanging bronze oil lamp, a large Roman coin, and - most charmingly - a standing dog figure, which might have been either a religious dedication or perhaps a toy. Read more.