Anthropologists have conducted a new analysis of skulls from the so-called “hobbit” fossils found in an Indonesian cave in 2003, and say their results add more evidence that the fossils come from a hitherto unknown race of tiny people. The researchers compared the hobbit skulls to those of modern humans and apes, as well as the fossil brain cases of early human ancestors. “The shape of the skull is consistent with what we would expect for a small archaic Homo,” said Karen Baab [National Geographic News], lead author of the new study.
When paleontologists unearthed a cluster of strange, hominid skeletons on the island of Flores, they had little idea that they were about to start a fierce debate that would divide the field of anthropology. But soon the researchers declared that the 18,000-year-old fossils came from people who were only three feet tall, and who were actually a different species of hominid, which researchers called Homo floresiensis. “These hobbits – hominids – appear to have survived when modern humans were all over the Earth at this time,” Baab said [The Guardian]. Since then, debate has raged over whether the hobbits were indeed an unknown species, or whether the individuals found in the cave were just modern humans with a disease that stunted their growth and gave them small brains, a condition called microcephaly.
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Two groups of researchers seem to have solved the mystery of how and when the first human settlers spread out through the Pacific Islands. One group studied the evolution of a stomach bacteria while the other examined the evolution of language, but both came up with remarkably congruous results. The evolutionary trajectory implied by words and bugs begins with an initial migration from Taiwan 5,000 years ago, with a first wave of people spreading to the Philippines and a second to western Polynesia [Wired News].
In the bacterial study, researchers took stomach samples from people native to Taiwan, Australia, Melanesia, Polynesia and New Guinea. They measured genetic variation in Helicobacter pylori, a common gut microbe that traveled with humans when they first left Africa more than 60,000 years ago…. They found that the [bacteria] from people’s guts in Polynesia and Melanesia–islands stretching from New Caledonia all the way to Samoa–were genetically similar to the samples from aboriginal people in Taiwan. What’s more, the Taiwanese bacteria had more genetic diversity than other populations [The Scientist]. Because genetic mutations accumulate over time, these results indicate that the early Taiwanese people were the ancestors of the other groups that split off over the centuries.
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Capuchin monkeys not only have the capacity to use tools, they also know which tool is best for the job at hand, according to a new study. Researchers observed capuchin monkeys in the wild testing out different stones and consistently settling on the heaviest, sturdiest stone to crack open palm nuts. Although anecdotal reports existed before, the new study is the first to systematically document tool use in capuchin monkeys. Because capuchins last shared a common ancestor with humans approximately 35 million years ago, the team writes, the capacity for stone-tool use evolved earlier than thought [New Scientist].
Researchers studied eight wild capuchins living in a forested area of Brazil. In several different trials, researchers planted two or three different rocks, of varying hardness, size, and weight, near where the monkeys were feeding. The choices ranged from crumbly sandstone to tough quartzite, with some artificial stones that the monkeys would not normally encounter also thrown in the mix. Capuchins chose the most effective stone for cracking nuts more than 90 percent of the time in four conditions. That figure fell slightly to 85 percent when the monkeys selected from artificial stones of the same size and different weights [Science News].
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When the first bands of early humans made their intrepid journey into the Americas, they found plenty of room to spread out, according to a new study. Researchers who conducted a genetic analysis of Native Americans say that they can trace their ancestry back to two groups of migrants who arrived in America around the same time, between 15,000 and 17,000 years ago, but took distinctly different routes. The researchers argue that one group moved down the Pacific coastline all the way to the tip of South America, and the other group crossed into North America through an open land corridor between ice sheets and settled near the Great Lakes.
Along the Pacific coastal route, travelers in skin boats are presumed to have hunted marine mammals and found shelter in shoreline refuges beyond the reach of the retreating glaciers…. Movements along the inland route – where big-game hunters originally from Siberia are believed to have migrated through a gap in the glaciers in present-day Northwest Territories and Alberta – led to the earliest mid-continental settlements in the New World, scientists believe [Canwest News Service].
Paleoanthropologists generally accept that the original colonizers of North and South America came from eastern Asia and migrated to the Americas after spending some time–perhaps several thousand years–in a region called Beringia, which included parts of Siberia and Alaska and the land bridge that once connected them [ScienceNOW Daily News]. But the question of where they went next has been a subject of considerable controversy, with some researchers arguing that harsh climate conditions didn’t allow humans to settle in North America until long after the crossing of the land bridge. While the new study isn’t likely to settle the argument, it supports the theory that humans quickly spread out over both continents.
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Minuscule diamond fragments found in a sediment layer dating from thousands of years ago are bolstering the theory that a catastrophic comet impact wiped out many forms of life in North America, including what are thought to have been the first human settlers of the continent, the so-called Clovis people. The nano-diamonds are buried at a level that corresponds to the beginning 12,900 years ago of the Younger Dryas, a 1,300-year-long cold spell during which North American mammoths, saber-toothed cats, camels and giant sloths became extinct. The Clovis culture of American Indians also appears to have fallen apart during this time [Reuters].
The new study adds evidence to the controversial theory, but some skeptics are not convinced. “The whole thing still does not make sense, and there are lots of contradictions,” said Christian Koeberl, a professor of geological sciences…. His chief reservation is that there is no crater. “A body of this size does not just blow up without a trace in the atmosphere,” Dr. Koeberl said. “Physics won’t have it” [The New York Times]. In reply, supporters of the theory say that some of the comet fragments may have exploded in midair, while others may have hit an ice sheet that was several miles thick, lessening the possibility of a crater forming.
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The small band of Homo sapiens that left Africa around 60,000 years ago, taking the first steps on a journey that would eventually disperse humans all around the world, may have been composed mostly of men. A new analysis of DNA variations in contemporary humans indicates that non-Africans descend from a population that contained far more males than females [New Scientist].
In the study, published in Nature Genetics [subscription required], researchers compared genetic samples from present-day African, European, and Asian populations. They were looking at the chromosomes that determine sex (two X chromosomes in women, one X and one Y chromosome in men), as well as the other 22 chromosome pairs, which are the same in both sexes. They examined the rate at which mutations randomly spread through the X chromosome over dozens or hundreds of generations as compared to the mutation rate in other, non-sex, chromosomes [AFP].
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In a muddy pit near the town of York in northern England, archaeologists have found a skull holding what they believe is the preserved remains of an “Iron Age brain.” Here’s how the noggin was first noticed: York Archaeological Trust dig team member Rachel Cubitt reached in [to the ditch] and, while she cleaned the soil-covered skull’s outer surface, “she felt something move inside the cranium. Peering through the base of the skull, she spotted an unusual yellow substance” [LiveScience]. Scans later showed that the yellow mass was in the shape of a shrunken brain, according to a press release from the University of York.
The skull was discovered in an area of extensive prehistoric farming landscape of fields, trackways and buildings dating back to at least 300 BC. The archaeologists believe the skull, which was found on its own in a muddy pit, may have been a ritual offering [BBC News]. Researchers declared it the oldest brain ever found in Britain, although it can’t touch the record for the oldest brain ever discovered: That honor belongs to the roughly 8,000-year-old scraps of brain tissue that were found in skeletons buried in a Florida peat bog. In the Florida case, the absence of bacteria in the acidic peat bogs allowed the organic tissue to be preserved; researchers still aren’t sure how the York brain was preserved or whether the yellow substance has any organic matter in it.
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The battle that has raged over creationism and evolution in the United States is likely to spread to the Islamic world, a scholar of science and religion argues in a new essay. But author Salman Hameed writes that the opening of a new front in the battle gives scientists an opportunity to reframe the debate. Better education, the spread of Internet access and news about U.S. controversies over evolution are provoking some Muslims worldwide to start to ask whether Islam is compatible with evolutionary theory, Hameed said. “Now is the time that these ideas are going to be solidified. We can shape it. There are positive ways to shape these ideas in which we can avert a mass rejection of evolution,” Hameed said [LiveScience].
The most fundamentalist form of creationism in the United States is based on a literal reading of the Bible, which implies that the earth and all its creatures were created by God in their present form over the course of six days; creationists say this narrative is in direct conflict with the idea that organisms slowly evolved over billions of years. However, Hameed notes that the Koran may be more compatible with evolutionary theory. One of the big evolution problems from the US creationist perspective is the age of the Earth. Logically speaking, if you believe in a 6000 or 10,000 year-old Earth, then you have to reject evolution. In the Muslim countries, young Earth creationism is nonexistent. The Koran is very vague about creation stories, specifically regarding the creation of the universe. If you accept an old Earth, then it makes it relatively easier to accept evolution [New Scientist].
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The tumult of the Spanish Inquisition, which began over 500 years ago, has echoed down through the generations of people living on the Iberian peninsula in a remarkable way. A new genetic study has revealed that many current Spaniards have Sephardic Jewish or North African heritage, indicating that their ancestors converted to Christianity during the religious upheaval of the 15th century in order to remain in Spain. The study showed that one in ten Iberians has a North African ancestor, while one in five had Jewish forebears.
This melting pot probably occurred after centuries of coexistence and tolerance among Muslims, Jews and Christians ended in 1492, when Catholic monarchs converted or expelled the Islamic population, called Moriscos. Sephardic Jews, whose Iberian roots extend to the first century AD, received much the same treatment. “They were given a choice: convert, go, or die,” says Mark Jobling, a geneticist at the University of Leicester, UK. Some of those that became Christian would have ended up contributing genes to the Iberian pool [New Scientist].
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Female macaques are much chattier than male macaques, according to a new study. The researchers say vocal communication is an important part of macaque social bonding and the findings may reflect similar patterns in the evolution of human language. Klaus Zuberbühler, who studies primate communication, says social animals communicate to resolve the constant tension between a “need to compete and a desire to cooperate” [New Scientist].
The researchers studied macaques living on Cayo Santiago island off Puerto Rico, and for three months they followed a group of macaques that consisted of 16 females and 8 males. Friendly monkey chit-chat included a variety of grunts, coos, and girneys (nasally whines, usually between mother and infant). The researchers counted the social vocalizations, excluding those that were used only to indicate food or predators, and found that females vocalized 13 times more often than the males. Researcher Nathalie Greeno says, “The results suggest that females rely on vocal communication more than males due to their need to maintain the larger social networks” [News Scientist].
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About 4,600 years ago in Germany’s fertile farm country a group of stone age people met a violent end, but the arrangement of their skeletons in four graves tells a story of love and family bonds. One particularly well-preserved grave holds what researchers say is the first known nuclear family, with an adult male and female cradling the bodies of their two sons. A DNA analysis of the skeletons’ bones and teeth confirmed their blood ties: “The two kids have her mitochondrial DNA, and his Y chromosome – that’s a nuclear family,” says molecular anthropologist Brian Kemp [New Scientist].
The group of 13 individuals includes adults aged 25 to 60 and children under the age of 9, and researchers believe that they were massacred. Says study coauthor Alistair Pike: “They were definitely murdered, there are big holes in their heads, fingers and wrists are broken.” At least five of the individuals show the effects of a violent attack, one even had the tip of a stone weapon embedded in a vertebra [BBC News].
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The fossilized pelvis of a Homo erectus woman who lived 1.2 million years ago on the banks of an Ethiopian river has been discovered, and while researchers say it casts new light on human evolution, some of their conclusions are challenging previous theories about these early human ancestors. The pelvis reveals a short, squat woman who wasn’t built for long-distance running, but also a woman with a wide birth canal to accommodate big-brained infants.
Study coauthor Scott Simpson says the pelvis’s wide birth canal indicates that hominds’ increasing brain size was a driving factor in human evolution. Getting through the birth canal is “the most gymnastic thing we ever do,” he says. To accommodate big-brained babies, humans must have developed larger and wider birth canals over time, but with few pelvic fossils, researchers had little idea when these changes began. The Busidima pelvis shows that a wide birth canal was already in place 1.2 million years ago [New Scientist].
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In a dusty cave in Israel, archaeologists have unearthed a 12,000-year-old grave that they say may be the resting spot of one of the earliest known shamans. The grave contains the artfully arranged bones of a roughly 45-year-old woman as well as a collection of animal and human body parts, including a complete human foot, 50 tortoise shells, and bones from a wild boar, an eagle, and a leopard.
“What was unusual here was there were so many different parts of different animals that were unusual, that were clearly put there on purpose,” said researcher Natalie Munro…. This care along with the animal parts point to the grave belonging to both an important member of the society and possibly a healer called a shaman…. Such healers mediate between the human and spirit worlds, often summoning the help of animal spirits along their quests, according to the researchers [LiveScience].
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Researchers have long debated whether human migration out of Africa was spurred by climate changes that forced the early humans to move along or by technological innovation that let them take advantage of new possibilities; now a new analysis of stone tools from southern Africa is lending support to the latter camp. Researchers determined that two types of tools were developed during the crucial age from 60,000 to 80,000 years ago when modern humans began to move towards new regions of the globe.
Researchers examined tools from nine sites in South Africa, Namibia, and Lesotho. The sophisticated Still Bay tools were made from hard, fine-grained rock called silcrete, and were fashioned between 71,000 and 71,900 years ago. The Howieson’s Poort implements were made between 59,500 and 64,800 years ago, and were composed of chipped silcrete rock attached to wood shafts to form weapons. Comparing these dates with palaeoenvironmental records failed to turn up a close correlation between the industries and dramatic climatic changes, [lead researcher Zenobia] Jacobs says. “We see no consistent pattern between the timing of these industries and major climatic changes” [Nature News].
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The Phoenician culture vanished from the Mediterranean following the fall of Carthage in 146 BC, when the Romans razed the city and (according to legend) salted the earth, but the Phoenician people didn’t fade away. A new genetic analysis shows that 1 in 17 men in the Mediterranean region have Phoenician DNA, and must be descended from those ancient seafarers.
The findings could fill a gap in the history of the Phoenician civilization, which originated two to three thousand years ago in the eastern Mediterranean—in what is now Lebanon and Syria—and included prominent traders, according to Chris Tyler-Smith, lead author…. “By the time of the Romans they more or less disappeared from history, and little has been known about them since” [National Geographic News].
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