Read moreLittle Foot, a fossilized Australopithecus Prometheus, an early hominid, has been dated as 3.67 million years old—making it an older relative of the famous 3.2 million-year-old Australopithecus, Lucy. Researchers used a dating method that measures isotopes in rock created by exposure to cosmic rays—the ratio of isotopes reveal how long the rock has been underground. The researchers say that the discovery lends evidence to the idea that there were multiple species of Australopithecus present in Africa at this time.
human evolution
Read more“What we’re seeing is perhaps the beginning of a unique characteristic of our own species – the origins of diversity,” said Dr Jay Stock, co-author of the study from the University of Cambridge’s Department of Archaeology and Anthropology. “It’s possible to interpret our findings as showing that there were either multiple species of early human, such as Homo habilis, Homo ergaster and Homo rudolfensis, or one highly diverse species. This fits well with recent cranial evidence for tremendous diversity among early members of the genus Homo.”
“If someone asked you ‘are modern humans 6 foot tall and 70kg?’ you’d say ‘well some are, but many people aren’t,’ and what we’re starting to show is that this diversification happened really early in human evolution,” said Stock.
The study is the first in 20 years to compare the body size of the humans who shared the earth with mammoths and sabre-toothed cats between 2.5 and 1.5 million years ago. It is also the first time that many fragmentary fossils – some as small as toes and tiny ankle bones no more than 5cm long – have been used to make body size estimates.
Read moreBased on the concentration of Fe-60 in the crust, Knie estimated that the supernova exploded at least 100 light-years from Earth—three times the distance at which it could’ve obliterated the ozone layer—but close enough to potentially alter cloud formation, and thus, climate. While no mass-extinction events happened 2.8 million years ago, some drastic climate changes did take place—and they may have given a boost to human evolution. Around that time, the African climate dried up, causing the forests to shrink and give way to grassy savanna. Scientists think this change may have encouraged our hominid ancestors as they descended from trees and eventually began walking on two legs.
That idea, as any young theory, is still speculative and has its opponents. Some scientists think Fe-60 may have been brought to Earth by meteorites, and others think these climate changes can be explained by decreasing greenhouse gas concentrations, or the closing of the ocean gateway between North and South America. But Knie’s new tool gives scientists the ability to date other, possibly more ancient, supernovas that may have passed in the vicinity of Earth, and to study their influence on our planet. It is remarkable that we can use these dull, slow-growing rocks to study the luminous, rapid phenomena of stellar explosions, Fields says. And they’ve got more stories to tell.
Read moreAbout 12,000 years ago, humans began farming, living in denser settlements and burying their dead, so skeletons younger than that are plentiful, said Stanley Ambrose, an African archaeologist and paleoanthropologist at the University of Illinois at Urbana-Champaign, who was not involved in the study.
But relatively little is known about the people who came before them. Only a handful of human burials around the world date from about 12,000 to 30,000 years ago, Ambrose said.
To learn more about this lost period of human history, Tryon and his colleagues took a second look at specimens that were sitting in the collections of the National Museums of Kenya in Nairobi. The artifacts were unearthed in the 1970s at rock shelters at Lukenya Hill, a granite promontory that overlooks the savanna in Kenya.
Among the finds was the top portion of an ancient skull. The team took several measurements of the skull, then compared it with skulls from Neanderthals, several other fossil human skulls from the same time and other periods, as well as those of modern-day humans.
Though the skull clearly belonged to a Homo sapien who was anatomically modern, its dimensions were markedly different from those of both the European skull and the African skulls from the same time. In addition, the skull was thickened, either from damage, nutritional stress or a highly active childhood. (There is not enough evidence to say the fossil represents a subspecies of Homo sapien, Tryon said.)
By measuring the ratio of radioactive isotopes of carbon (or carbon atoms with different numbers of neutrons), the team concluded that the skull was about 22,000 years old. That means the ancient human would have lived during the height of the last ice age.
Modern-day Africans have greater genetic diversity than other populations. But the new findings suggest that during this early period of human history, Africa may have supported even greater human diversity, with small, offshoot lineages that no longer exist today, Tryon said.
Ancient Arabian Stones Hint at How Humans Migrated Out of Africa
Previous research had suggested that the exodus from Africa started between 70,000 and 40,000 years ago. However, a genetic analysis reported in April hinted that modern humans might have begun their march across the globe as early as 130,000 years ago, and continued their expansion out of Africa in multiple waves.
In addition, stone artifacts recently unearthed in the Arabian Desert date to at least 100,000 years ago. This could be evidence of an early modern-human exodus out of Africa, scientists say. However, it’s possible that these artifacts weren’t created by modern humans; a number of now-extinct human lineages existed outside Africa before or at the same time when modern humans migrated there. For instance, the Neanderthals, the closest known extinct relatives of modern humans, lived in both Europe and Asia around that time.
To help shed light on the role the Arabian Peninsula might have played in the history of modern humans, scientists compared stone artifacts recently excavated from three sites in the Jubbah lake basin in northern Saudi Arabia with items from northeast Africa excavated in the 1960s. Both sets of artifacts were 70,000 to 125,000 years old. Back then, the areas that are now the Arabian and Sahara deserts were far more hospitable places to live than they are now, which could have made it easier for modern humans and related lineages to migrate out of Africa.
“Far from being a desert, the Arabian Peninsula between 130,000 and 75,000 years ago was a patchwork of grasslands and savanna environments, featuring extensive river networks running through the interior,” Scerri said.
The northeast African stone tools the researchers analyzed were similar to ones previously found near modern-human skeletons. The scientists found that stone artifacts at two of the three Arabian sites were “extremely similar” to the northeast African stone tools, Scerri told Live Science. At the very least, Scerri said, this finding suggests that there was some level of interaction between the groups in Africa and those in the Arabian Peninsula, and might hint that these Arabian tools were made by modern humans.
Surprisingly, Scerri said, tools from the third Arabian site the researchers analyzed were “completely different.” “This shows that there was a number of different tool-making traditions in northern Arabia during this time, often in very close proximity to each other,” she said.
One possible explanation for these differences is that the artifacts were made by different human lineages. Future research needs to uncover skeletal remains with ancient tools unearthed from the Arabian Peninsula to help solve this mystery, Scerri noted. Unless skeletal remains are found near such artifacts, it will remain uncertain whether modern humans or a different human lineage might have made them.
“It seems likely that there were multiple dispersals into the Arabian Peninsula from Africa, some possibly very early in the history of Homo sapiens,” Scerri said. “It also seems likely that there may have been multiple dispersals into this region from other parts of Eurasia. These features are what make the Arabian Peninsula so interesting.”
Ancient migrants out of Africa and from Eurasia might have encountered a number of different populations in the Arabian Peninsula, Scerri said. Some of these groups may have adapted to their environment more than others had, which raises the intriguing question:
“Did the exchange of genes and knowledge between such groups contribute to our ultimate success as a species?” Scerri said.
Ancient Arabian Stones Hint at How Humans Migrated Out of Africa
Read more "Ancient Arabian Stones Hint at How Humans Migrated Out of Africa "Transmission #1 of the Cosmic Anthropology Broadcast System: The Neanderthal Pride Ep
The Neanderthal Pride ep Taking a look at the nature and complexity of human evolution: past, present and future. WORKS MENTIONED: X-Men: First Class, X-Men 2 Crux by Ramez Naam [sequel to Nexus] newuniversal Brookings Report The Tomorrow People American Horror Story: Coven LINKS: http://mobile.nytimes.com/2014/08/17/magazine/should-you-fear-the-pizzly-bear.html [HYBRIDIZATION] http://www.livescience.com/46636-how-tibetans-survive-high-altitude.html [DENISOVAN DNA] http://www.nature.com/news/neanderthals-bone-technique-redrafts-prehistory-1.15739 http://en.wikipedia.org/wiki/Neanderthal_genome_project http://io9.com/google-wants-to-create-a-map-of-the-perfectly-healthy-h-1610873338 Interview with George […]
Read more "Transmission #1 of the Cosmic Anthropology Broadcast System: The Neanderthal Pride Ep"Read moreAround 50,000 years ago, there is widespread evidence of producing bone and antler tools, heat-treated and flaked flint, projectile weapons, grindstones, fishing and birding equipment and a command of fire.
“Was this driven by a brain mutation, cooked foods, the advent of language or just population density?”
Dr Hare and his colleagues argue that human society advanced when people started being nicer to each other, which entails having a little less testosterone in action.
“If prehistoric people began living closer together and passing down new technologies, they’d have to be tolerant of each other. The key to our success is the ability to cooperate and get along and learn from one another,” said Robert Cieri, a student at the University of Utah and the first author on the study published in the journal Current Anthropology.
In their study, the scientists compared the brow ridge, facial shape and interior volume of 13 modern human skulls older than 80,000 years, 41 skulls from 10,000 to 38,000 years ago, and a global sample of 1,367 20th century skulls from 30 different ethnic populations.
The trend that emerged was toward a reduction in the brow ridge and a shortening of the upper face, traits which generally reflect a reduction in the action of testosterone.
“Heavy brows were out, rounder heads were in, and those changes can be traced directly to testosterone levels acting on the skeleton,” said Prof Steven Churchill of Duke University, a co-author on the study.
Read moreTibetans live in a region that averages more than 4,000 meters above sea level. (Not for nothing is it called the roof of the world.) How did they come to be able to cope with their extreme environs? Some researchers in China and the United States think they might know, and their findings were published Wednesday in Nature. By sequencing DNA from a group of Tibetans and comparing the code to other gene databases, the researchers have discovered that Tibetans are inheritors of an ancient trait that helps regulate the oxygenation in their blood. But surprisingly, this trait did not arise in Homo sapiens. Rather, it came from another group of humans, the Denisovans—mysterious, little-known hominid cousins that died out some 40,000 years ago.
The new study on Tibetans demonstrates for the first time an evolutionary advantage conferred directly by Denisovans, an adaptation that seems to be singular to the Tibetan people. For people whose ancestors lived in milder altitudes, experiencing a dearth of oxygen at great heights causes the level of hemoglobin, the protein that carries oxygen in blood, to increase in attempt to compensate. But this raises the likelihood of cardiac events in the short term, and it is unhelpful for reproduction, as it increases the risk of preeclampsia (hypertension during pregnancy). Tibetans don’t have the same reaction to elevation: They have greater fitness and higher fertility even when there is little to breathe. This, along with other respiratory adaptations, allows them to thrive where others cannot.
Denisovans and Neanderthals are called extinct human “species”—a term that used to demark a clear line between two organisms incapable of interbreeding to produce fertile offspring. But the definition is no longer so clear. We know that these hominin cousins did couple with our Homo sapien ancestors—and some of us have inherited from them valuable modern traits. How we define “humans” past and present is a subject to contemplate—as fitting for scientists as for pilgrims to think about on their journeys across Tibetan plains.
fuckyeahdarkextropian: “Human facial structure evolved to tolerate punches to the head, according to new research that suggests our ancestors spent a lot of time fighting. Such ancestors likely included the australopiths, which lived 4 to 2 million years ago in Africa. “The australopiths were characterized by a suite of traits that may have improved fighting […]
Read moreHerpes viruses have been infecting and co-diverging with their vertebrate hosts for hundreds of millions of years. The primate simplex viruses exemplify this pattern of virus-host co-divergence, at a minimum, as far back as the most recent common ancestor of New World monkeys, Old World monkeys, and apes.
Humans are the only primate species known to be infected with two distinct herpes simplex viruses: HSV-1 and HSV-2. Human herpes simplex viruses are ubiquitous, with over two-thirds of the human population infected by at least one virus.
Here, we investigated whether the additional human simplex virus is the result of ancient viral lineage duplication or cross-species transmission.
Evolutionary Origins of Human Herpes Simplex Viruses 1 and 2 – http://m.mbe.oxfordjournals.org/content/early/2014/06/04/molbev.msu185.abstract
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The Committee to Nuke Elysium 