Ancient-human genomes plucked from cave dirt. IAET SB RAS/Sergei Zelensky Researchers plan the sampling of sediments in Siberia's Denisova cave.
Bones and teeth aren’t the only ways to learn about extinct human relatives. For the first time, researchers have recovered ancient-human DNA without having obvious remains — just dirt from the caves the hominins lived in. The technique opens up a new way to probe prehistory. From sediments in European and Asian caves, a team led by geneticist Viviane Slon and molecular biologist Matthias Meyer, both at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, sequenced genomes of cell structures called mitochondria from Neanderthals and another hominin group, the Denisovans. “It’s exciting to see that you can end up with a whole pile of ancient-human DNA from just dirt,” says Michael Bunce, an evolutionary biologist at Curtin University in Perth, Australia. Slon and Meyer are not the first to decode ancient dirt. Dirt detectives J. But when? How sliced meat drove human evolution.
The most tedious part of a chimpanzee’s life is chewing.
Our primate cousins spend 6 hours a day gnashing fruits and the occasional monkey carcass—all made possible by the same type of big teeth and large jaws our early ancestors had. So why are our own teeth and jaws so much smaller? A new study credits the advent of simple stone tools to slice meat and pound root vegetables, which could have dramatically reduced the time and force needed to chew, thus allowing our more immediate ancestors to evolve the physical features required for speech.
The reason modern humans are able to spend so little time chewing is that “we eat a much higher quality diet than our ancestors,” says Daniel Lieberman, an evolutionary anthropologist at Harvard University and an author of the new study. Whereas chimpanzees survive mostly on fruit, humans eat foods that pack more nutrients and energy into smaller portion sizes—namely, meat.
Chew on this: Study of ancient teeth bites theory of early primate disappearance. Fifty-six million years ago, just before earth's carbon dioxide levels and average temperatures soared, many species of primitive primates went extinct in North America for reasons unclear to scientists.
Now, a study of fossilized molars appears to exonerate one potential culprit in the animals' demise: competition with primitive rodents for food. In a study described in an advance online article in the American Journal of Physical Anthropology and conducted primarily by Kristen Prufrock, now a graduate student at the Johns Hopkins University School of Medicine, a team of paleontologists examined dental clues to the diets of so-called stem primates and rodents who plied North America at the end of the Paleocene epoch. Other paleontologists had suggested many of the stem primates -- which superficially resembled rodents but had some primate characteristics, such as long, grasping fingers -- died off because rodents outcompeted them for their preferred foods.
Doug M. Raw Stone Age Meals Got Tenderizing Treatment. Chimpanzees spend about half their day chewing.
"And for context, think about how much time a day you spend chewing. " Daniel Lieberman, a professor of human evolutionary biology at Harvard University. "So how did we make that transition, from spending most of our day or half of our day chewing, to spending less than five percent? " Cooking certainly tenderizes food, making it easier to chew and digest. But evidence for human cookfires goes back only about 500,000 years, if that. Lucky volunteers got to experience that, by chewing the food. Mysterious New Human Species Emerges from Heap of Fossils. In October 2013 scientists working in South Africa announced that they had discovered a trove of fossil human remains in the pitch-black depths of an underground cave system.
They began a rapid recovery effort that yielded some 1,550 specimens of bones and teeth—just a fraction of the material at the site, yet already the largest assemblage of human fossils ever found in all of Africa. Now the team has published its eagerly anticipated analyses of the remains, and the conclusions are startling.
The researchers suggest that the fossils represent a previously unknown species in our genus, Homo, one that had a peculiar mix of physical traits and engaged in surprisingly sophisticated behavior for its brain size. But the age of the fossils has yet to be determined, leaving other scientists unsure of what to make of them. But exactly where H. naledi belongs in the human family tree, apart from somewhere on the Homo branch, is unclear. The team’s claims have met with skepticism. Teeth from China Reveal an Early Human Trek out of Africa. S.
Xing and X-J. Wu These 47 human teeth, dated to 80,000-120,000 years ago, were found in a limestone cave system in Daoxian, China. Teeth from a cave in south China show that Homo sapiens reached China around 100,000 years ago — a time at which most researchers had assumed that our species had not trekked far beyond Africa. Nature Podcast. Discovery of oldest human DNA in Spanish cave sheds light on evolution. Researchers have read strands of ancient DNA teased from the thigh bone of an early human who died 400,000 years ago in what is now northern Spain.
The genetic material was pieced together from a clutch of cells found in bone fragments – the oldest human remains ever to yield their genetic code.