tagged w/ neanderthals
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The New York Times...
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December 26, 2011
The Hormone Surge of Middle Childhood
By NATALIE ANGIER
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PART ONE...
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VIEWED superficially, the part of youth that the psychologist Jean Piaget called middle childhood looks tame and uneventful, a quiet patch of road on the otherwise hairpin highway to adulthood.
Said to begin around 5 or 6, when toddlerhood has ended and even the most protractedly breast-fed children have been weaned, and to end when the teen years commence, middle childhood certainly lacks the physical flamboyance of the epochs fore and aft: no gotcha cuteness of babydom, no secondary sexual billboards of pubescence.
Yet as new findings from neuroscience, evolutionary biology, paleontology and anthropology make clear, middle childhood is anything but a bland placeholder. To the contrary, it is a time of great cognitive creativity and ambition, when the brain has pretty much reached its adult size and can focus on threading together its private intranet service — on forging, organizing, amplifying and annotating the tens of billions of synaptic connections that allow brain cells and brain domains to communicate.
Subsidizing the deft frenzy of brain maturation is a distinctive endocrinological event called adrenarche (a-DREN-ar-kee), when the adrenal glands that sit like tricornered hats atop the kidneys begin pumping out powerful hormones known to affect the brain, most notably the androgen dihydroepiandrosterone, or DHEA. Researchers have only begun to understand adrenarche in any detail, but they see it as a signature feature of middle childhood every bit as important as the more familiar gonadal reveille that follows a few years later.
Middle childhood is when the parts of the brain most closely associated with being human finally come online: our ability to control our impulses, to reason, to focus, to plan for the future.
Young children may know something about death and see monsters lurking under every bed, but only in middle childhood is the brain capable of practicing so-called terror management, of accepting one’s inevitable mortality or at least pushing thoughts of it aside.
Other researchers studying the fossil record suggest that a prolonged middle childhood is a fairly recent development in human evolution, a luxury of unfolding that our cousins the Neanderthals did not seem to share. Still others have analyzed attitudes toward middle childhood historically and cross-culturally. The researchers have found that virtually every group examined recognizes middle childhood as a developmental watershed, when children emerge from the shadows of dependency and start taking their place in the wider world.
Much of the new work on middle childhood was described in a recent special issue of the journal Human Nature. As a research topic, “middle childhood has been very much overlooked until recently,” said David Lancy, an anthropologist at Utah State University and a contributor to the special issue. “Which makes it all the more exciting to participate in the field today.”
The anatomy of middle childhood can be subtle. Adult teeth start growing in, allowing children to diversify their diet beyond the mashed potatoes and parentally dissected Salisbury steak stage. The growth of the skeleton, by contrast, slows from the vertiginous pace of early childhood, and though there is a mild growth spurt at age 6 or 7, as well as a bit of chubbying up during the so-called adiposity rebound of middle childhood, much of the remaining skeletal growth awaits the superspurt of puberty.
“Adulthood is defined by being skeletally as well as sexually mature,” said Jennifer Thompson of the University of Nevada, Las Vegas. “A girl may have her first period at 11 or 12, but her pelvis doesn’t finish growing until about the age of 18.”
The 18-year time frame of human juvenility far exceeds that seen in any other great ape, Dr. Thompson said. Chimpanzees, for example, are fully formed by age 12. With her colleague Andrew J. Nelson of the University of Western Ontario, Dr. Thompson analyzed fossil specimens from Neanderthals, Homo erectus and other early hominids, and concluded that their growth pattern was more like that of a chimpanzee than a modern human: By age 12 or 14, they had reached adult size.
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CONTINUED...
.The New York Times...
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December 26, 2011
The Hormone Surge of Middle... more
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WWH, That still doesn’t explain Rick Perry!
tgdaily.com - Our ancient human ancestors interbred with other early hominids as well as Neanderthals, new research indicates.WWH, That still doesn’t explain Rick Perry!
tgdaily.com - Our ancient human... more
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Time for the news, bros. It’s boring, so it might as well be short. Here now are the headlines, rewritten so you don’ t have to read them.Time for the news, bros. It’s boring, so it might as well be short. Here now... more
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Neanderthals in Europe died out because they were overrun by hordes of modern humans from Africa who flooded into the region 40,000 years ago, scientists have claimed.
link:http://www.telegraph.co.uk/science/evolution/8668713/Neanderthals-overrun-by-early-
humans.htmlNeanderthals in Europe died out because they were overrun by hordes of modern humans... more
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How the human penis lost its spines
By Elizabeth Landau, CNN
March 9, 2011 6:00 p.m. EST
Scientists are seeking to understand the underlying reasons why humans and chimpanzees have key differences.
(CNN) -- You've read the headline, and it probably made you giggle. Go ahead. Get it out of your system. Then take a deep breath and consider how evolution affected a few specific body parts, and why.
Humans and chimpanzees share more than 97% of DNA, but there are some fairly obvious differences in appearance, behavior and intellect. Now, scientists are learning more than ever about what makes us uniquely human.
We know that humans have larger brains and, within the brain, a larger angular gyrus, a region associated with abstract concepts. Also, male chimpanzees have smaller penises than humans, and their penises have spines. Not like porcupine needles or anything, but small pointy projections on the surface that basically make the organ bumpy.
Gill Bejerano, a biologist at Stanford University School of Medicine, and colleagues wanted to further investigate why humans and chimpanzees have such differences. They analyzed the genomes of humans and closely related primates and discovered more than 500 regulatory regions -- sequences in the genome responsible for controlling genes -- that chimpanzees and other mammals have, but humans do not. In other words, they are making a list of DNA that has been lost from the human genome during millions of years of evolution. Results from their study are published in the journal Nature.
Think of it like light bulbs and their switches, where the light bulbs are genes and the switches are these controlling DNA sequences. If there's no bulb, the switch can't turn the light on. Now imagine there's one bulb and five switches to turn it on at different times in different places. If you take one of the switches away, the bulb still works in the four other contexts, but not in the fifth.
This study looks at two particular switches. Bejerano and colleagues took the switch information from a chimpanzee's genome and essentially "hooked it up" to a reporter gene, a gene whose effects scientists can track as an organism develops. They injected the reporter gene in a mouse egg to see what the switch would do.
They found that in one case, a switch that had been lost in humans normally turns on an androgen receptor at the sites where sensory whiskers develop on the face and spines develop on the penis. Mice and many other animals have both of these characteristics, and humans do not.
"This switch controls the expression of a key gene that's required for the formation of these structures," said David Kingsley, a study co-author at Stanford University. "If you kill that gene -- smash the lightbulb -- which has been done previously in mouse genetics, the whiskers don't grow as much and the penile spines fail to form at all."
Humans have kept the "light bulb," however -- we have androgen receptors, but ours don't produce whiskers or penile spines, he said. Chimpanzees do have small sensory whiskers, not as externally obvious as in cats or mice, but we don't have them at all.
To sum up: Humans lack a switch in the genome that would "turn on" penile spines and sensory whiskers. But our primate relatives, such as chimpanzees, have the switch, and that's why they differ from us in these two ways.
And humans are somewhat exceptional in this regard -- a lot of male primates have bumpy penises; mice, which are rodents, have them, too.
The basic idea of natural selection is that over many generations, an animal species loses some traits that are disadvantageous to survival or reproduction (or just don't do much, in some cases), and develops features that carry benefits. Traits that allow members of a species to have more children will eventually become more widespread, as they are passed on genetically to more and more offspring. In humans, this process takes place over hundreds of thousands to millions of years. So, there must be a good reason that the guys you know look different.
In fact, speculation abounds about what purpose the spines serve. One theory is that they are used in sperm competition; if the male's goal is to get his mate pregnant, he will want to take out her previous partner's sperm if she's recently had sex. The bumpy penis may be better for removing that sperm from the female, scientists theorize.
There's probably less debate about why humans reap benefits from having larger brains than chimpanzees, Kingsley said.
The other "switch" examined in this study probably has to do with the expansion of brain regions in humans. Kingsley and colleagues believe they have found a place in their genome comparisons where the loss of DNA in humans may have contributed to the gain of neurons in the brain. That is to say, when humans evolved without a particular switch, the absence of that switch allowed the brain to grow further.
The earliest human ancestors probably had sensory whiskers, penile spines and small brains, Kingsley said. Evolutionary events to remove the whiskers and spines and enlarge the brain probably took place after humans and chimpanzees split apart as separate species (Some 5 million to 7 million years ago), but before Neanderthals and humans diverged (about 600,000 years ago), Kingsley said
We know that Neanderthals had big brains like ours. They probably didn't have penile spines, either. There are traces of the Neanderthal genome in humans today, meaning Neanderthals and humans probably mated.
"The fact that Neanderthals were also missing penile spines is at least consistent with the idea that the mating structures of Neanderthals and modern humans were compatible enough that some interbreeding occurred," Kingsley said.How the human penis lost its spines
By Elizabeth Landau, CNN
March 9, 2011 6:00... more
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by Sarah Laskow, Media Consortium blogger
Last week, environmentalists and food advocates warily welcomed the news that Walmart plans to expand its local, sustainable food program. The company announced it would double its sales of locally grown food by 2015 and, in new markets, would source from small and midsized producers. Given Walmart’s market share, this announcement is generally understood to be a positive development for the sustainable food movement.
Sustainable food, however, has grown beyond the dictum to eat simply locally and organically grown food. Farms have sprung up on rooftops, home canning of fruits and vegetables has taken off, and composting is de rigueur. A common thread runs through this movement, one with a long tradition in American life—a preference for self-reliance.
“Independence is for Neanderthals”
In her new book, The Resilient Gardener, Chelsea Green author Carol Deppe writes about her garden not just as a local, sustainable source of food, but as a tool for building a sustainable community.
“The resilient gardener knows we have our ups and downs, as individuals, families, societies, and as a species,” she says. “The resilient garden is designed and managed so that when things go wrong, they have less impact.”
Deppe argues that growing staple crops like potatoes, corn, beans, and squash, and learning how to store vegetables and save seeds will help communities thrive, even in times of erratic climates.
“I aim for appropriate self-reliance, not for independence,” she says. “Independence is for Neanderthals.”
Communal eating
Yes! Magazine’s Vicki Robin has been feeding herself only with produce from a friend’s farm and a handful of other necessities sourced within a 10-mile radius of her home—which is on an island in Washington State. She’s been documenting her “10-mile diet” since the beginning of September, and as it came to a close in early October, she wrote: “The overall news is that we are actually on our way to at least partial food self sufficiency on the island, and could get closer with some changes—if we eat what we can grow here and not insist on what cannot grow here….”
From the farm to the city
For Robin, eating locally often meant eating food grown by neighbors. For city-dwellers, “local” is much more flexible. In New York City, for instance, local food at the city’s Greenmarkets can come from more than two hundred miles away, as farmers make weekly drives from upstate New York, Vermont, or southern New Jersey.
Although urban farms have drawn attention as a innovative solution for localizing food production, no one is arguing that a city could feed itself entirely from its rooftops or empty lots. It may not even be wise to dedicate large chunks of city space to agriculture, as Daniel Nairn argues at Grist: Cities need to be dense to promote energy efficiency. Jason Mark, editor of the Earth Island Journal, also writes at Change.org that most urban farms, so far, are not supporting themselves financially.
Sustained by subsidies
For American agriculture across the board, subsidies are a key to financial sustainability. The USDA has funded the growth of corn and soy megafarms in the Midwest, and earnings from outside jobs supplement the incomes of many small or midsized farmers. So far, outside support for urban agriculture has come primarily from private foundations, although earlier this year Rep. Marcy Kaptur (D-OH) introduced a bill that would create an Office of Urban Agriculture within the federal agriculture department.
Still, increasing outside funding for urban agriculture may not be the key to sustaining it. “The question of whether farms can become self-sufficient has major implications for the larger drive to create a green economy,” Mark writes. For the green economy to work, it has to be self-reliant.
Mark highlights Dig Deep Farm in the suburbs of San Francisco, CA, as an example.
“To reach profitability, we have to reach a lot of people,” Hank Herrera, one of the farm’s owners, told Mark. “Our goal is to have enough productivity to reach scale, to have the poundage to really feed people.”
To that end, Herrera and his partner, Abeni Ramsey, are looking for more corners of land in the vicinity of their farm to convert into growing space.
Farm ecosystems
Communities sustained by good food practices extend beyond humans to the natural ecosystem of worms and insects that lives in the dirt, helping to enrich and clean it. As Sara Rubin writes at Campus Progress, “A farmer attentive to natural systems will often rejoice over a handful of soil packed with the tiny squirmers, but mostly because it’s packed with microscopic critters, too. An entire ecosystem of beneficial fungi and bacteria and tiny insects can be active below the soil surface.”
That community of underground wrigglers contributes to the resilience of human communities, too. Healthy bugs and bacteria crowd out dangerous pathogens that have led to food-related outbreaks of salmonella, for instance, in the past few years.
Environmentalists should welcome Walmart’s new-found dedication to local foods. It shows that the first battle for a sustainable food system has been won, freeing up time and energy to develop new, exciting projects that will ultimately strengthen communities, not corporations.
This post features links to the best independent, progressive reporting about the environment by members of The Media Consortium. It is free to reprint. Visit the Mulch for a complete list of articles on environmental issues, or follow us on Twitter. And for the best progressive reporting on critical economy, health care and immigration issues, check out The Audit, The Pulse, and The Diaspora. This is a project of The Media Consortium, a network of leading independent media outlets.by Sarah Laskow, Media Consortium blogger
Last week, environmentalists and food... more
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by Sarah Laskow, Media Consortium blogger
Last week, environmentalists and food advocates warily welcomed the news that Walmart plans to expand its local, sustainable food program. The company announced it would double its sales of locally grown food by 2015 and, in new markets, would source from small and midsized producers. Given Walmart’s market share, this announcement is generally understood to be a positive development for the sustainable food movement.
Sustainable food, however, has grown beyond the dictum to eat simply locally and organically grown food. Farms have sprung up on rooftops, home canning of fruits and vegetables has taken off, and composting is de rigueur. A common thread runs through this movement, one with a long tradition in American life—a preference for self-reliance.
“Independence is for Neanderthals”
In her new book, The Resilient Gardener, Chelsea Green author Carol Deppe writes about her garden not just as a local, sustainable source of food, but as a tool for building a sustainable community.
“The resilient gardener knows we have our ups and downs, as individuals, families, societies, and as a species,” she says. “The resilient garden is designed and managed so that when things go wrong, they have less impact.”
Deppe argues that growing staple crops like potatoes, corn, beans, and squash, and learning how to store vegetables and save seeds will help communities thrive, even in times of erratic climates.
“I aim for appropriate self-reliance, not for independence,” she says. “Independence is for Neanderthals.”
Communal eating
Yes! Magazine’s Vicki Robin has been feeding herself only with produce from a friend’s farm and a handful of other necessities sourced within a 10-mile radius of her home—which is on an island in Washington State. She’s been documenting her “10-mile diet” since the beginning of September, and as it came to a close in early October, she wrote: “The overall news is that we are actually on our way to at least partial food self sufficiency on the island, and could get closer with some changes—if we eat what we can grow here and not insist on what cannot grow here….”
From the farm to the city
For Robin, eating locally often meant eating food grown by neighbors. For city-dwellers, “local” is much more flexible. In New York City, for instance, local food at the city’s Greenmarkets can come from more than two hundred miles away, as farmers make weekly drives from upstate New York, Vermont, or southern New Jersey.
Although urban farms have drawn attention as a innovative solution for localizing food production, no one is arguing that a city could feed itself entirely from its rooftops or empty lots. It may not even be wise to dedicate large chunks of city space to agriculture, as Daniel Nairn argues at Grist: Cities need to be dense to promote energy efficiency. Jason Mark, editor of the Earth Island Journal, also writes at Change.org that most urban farms, so far, are not supporting themselves financially.
Sustained by subsidies
For American agriculture across the board, subsidies are a key to financial sustainability. The USDA has funded the growth of corn and soy megafarms in the Midwest, and earnings from outside jobs supplement the incomes of many small or midsized farmers. So far, outside support for urban agriculture has come primarily from private foundations, although earlier this year Rep. Marcy Kaptur (D-OH) introduced a bill that would create an Office of Urban Agriculture within the federal agriculture department.
Still, increasing outside funding for urban agriculture may not be the key to sustaining it. “The question of whether farms can become self-sufficient has major implications for the larger drive to create a green economy,” Mark writes. For the green economy to work, it has to be self-reliant.
Mark highlights Dig Deep Farm in the suburbs of San Francisco, CA, as an example.
“To reach profitability, we have to reach a lot of people,” Hank Herrera, one of the farm’s owners, told Mark. “Our goal is to have enough productivity to reach scale, to have the poundage to really feed people.”
To that end, Herrera and his partner, Abeni Ramsey, are looking for more corners of land in the vicinity of their farm to convert into growing space.
Farm ecosystems
Communities sustained by good food practices extend beyond humans to the natural ecosystem of worms and insects that lives in the dirt, helping to enrich and clean it. As Sara Rubin writes at Campus Progress, “A farmer attentive to natural systems will often rejoice over a handful of soil packed with the tiny squirmers, but mostly because it’s packed with microscopic critters, too. An entire ecosystem of beneficial fungi and bacteria and tiny insects can be active below the soil surface.”
That community of underground wrigglers contributes to the resilience of human communities, too. Healthy bugs and bacteria crowd out dangerous pathogens that have led to food-related outbreaks of salmonella, for instance, in the past few years.
Environmentalists should welcome Walmart’s new-found dedication to local foods. It shows that the first battle for a sustainable food system has been won, freeing up time and energy to develop new, exciting projects that will ultimately strengthen communities, not corporations.
This post features links to the best independent, progressive reporting about the environment by members of The Media Consortium. It is free to reprint. Visit the Mulch for a complete list of articles on environmental issues, or follow us on Twitter. And for the best progressive reporting on critical economy, health care and immigration issues, check out The Audit, The Pulse, and The Diaspora. This is a project of The Media Consortium, a network of leading independent media outlets.by Sarah Laskow, Media Consortium blogger
Last week, environmentalists and food... more
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For decades scientists believed Neanderthals developed `modern' tools and ornaments solely through contact with Homo sapiens, but new research from the University of Colorado Denver now shows these sturdy ancients could adapt, innovate and evolve technology on their own.
link: http://www.sciencedaily.com/releases/2010/09/100921171412.htmFor decades scientists believed Neanderthals developed `modern' tools and... more
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So, if some folks have more Neanderthal slouching around their genome than others, who might these four percenters be? We have theories.So, if some folks have more Neanderthal slouching around their genome than others, who... more
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Many people alive today possess some Neanderthal ancestry, according to a landmark scientific study.
The finding has surprised many experts, as previous genetic evidence suggested the Neanderthals made little or no contribution to our inheritance.
The result comes from analysis of the Neanderthal genome - the "instruction manual" describing how these ancient humans were put together.
The genomes of 1% to 4% of people in Eurasia come from Neanderthals.
The results show that the genomes of non-Africans (from Europe, China and New Guinea) are closer to the Neanderthal sequence than are those from Africa.
The most likely explanation, say the researchers, is that there was limited mating, or "gene flow", between Neanderthals and the ancestors of present-day Eurasians.
This must have taken place just as people were leaving Africa, while they were still part of one pioneering population. This mixing could have taken place either in North Africa, the Levant or the Arabian Peninsula, say the researchers.
http://news.bbc.co.uk/2/hi/science/nature/8660940.stmMany people alive today possess some Neanderthal ancestry, according to a landmark... more
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We are currently the only human species alive, but as recently as 24,000 years ago another one walked the earth — the Neanderthals.
These extinct humans were the closest relatives we had, and tantalizing new hints from researchers suggest that we might have been intimately close indeed. The mystery of whether Neanderthals and us had sex might be solved if the entire Neanderthal genome is reported soon as expected. The matter of why they died and we succeeded, however, remains an open question.
Maybe not nasty and brutish, but still short
First recognized in the Neander Valley in Germany in 1856, Neanderthals revealed that modern humans possess a rich and complex family tree that includes now-extinct relatives.
Neanderthals — also called Neandertals, due to changes in German spelling over the years — had robust skeletons that gave them wide bodies and short limbs compared to us. This made them more like wrestlers, while modern humans in comparison are more like long-distance runners.
They were probably less brutish and more like modern humans than commonly portrayed. Their brains were at least as large as ours. They controlled fire, expertly made stone tools, were proficient hunters, lived complex social groups and buried their dead. The discovery of the remains of an adult male Neanderthal with severely deformed arm bones, suggesting a major disability perhaps since childhood, hints they may have taken care of their sick. Genetic research even suggests they might have shared basic language capabilities with modern humans.
"They were a lot more closely related to us than anything alive today," said paleoanthropologist Katerina Harvati at the University of Tübingen in Germany.
Why did Neanderthals go extinct?
Roughly 30,000 years ago, the Neanderthals disappeared, although pockets might have survived until as recently as 24,000 years ago. Since they vanished just as modern humans were emerging there, scientists have long speculated that we might have driven their extinction.
"I think we did away with our competition," asserted paleoanthropologist Ian Tattersall at the American Museum of Natural History in New York. "We either did it indirectly by out-competing them over resources or directly by conflict. Homo sapiens is completely different from any other hominid that ever existed — we process information about the world in a different way."
Other scientists have suggested that Neanderthals weren't destroyed so much as absorbed by modern humans. "Maybe they were wiped out by disease or by conquerors, but maybe they did leave important genes into our gene pool," said paleoanthropologist Milford Wolpoff at the University of Michigan.
Paleoanthropologist Tim Weaver at the University of California at Davis also noted that our species apparently could live at higher population densities than Neanderthals. As a result, this slight difference, with or without interbreeding, would have led to us replacing them.
"A lot of scenarios have been imagined, from peaceful 'flower child' behavior to violent interactions to even cannibalism," Harvati said. "I think a lot of these scenarios happened. I think we probably tried interbreeding and maybe it worked, maybe it didn't. I'm sure there was violence at times. I think in some places they went extinct before modern humans even arrived. But you don't even need any of those if there is even a slight advantage in how many offspring modern humans produce successfully as opposed to Neanderthals."
However, if Neanderthals did coincide with modern humans until 24,000 years ago, then we might not have had anything to do with their disappearance. Instead, evolutionary biologist Clive Finlayson at the Gibraltar Museum in Spain speculates the Neanderthals fell victim to a cooling of the climate that deteriorated their environment too rapidly for them to adapt.
Did Neanderthals have sex with modern humans?
Did hybrids occur between humans and Neanderthals? In a surprisingly bold statement, the leader of the international consortium of researchers sequencing the Neanderthal genome, Svante Pääbo, recently said he was "sure that they had sex."
"Would they have recognized each other as possible mates?" Harvati asked. "We know when closely related primate species meet, they sometimes interbreed in nature, not just in zoos, and this is something we see not just in primates, but with other closely related species among mammals."
Past research had shown that Neanderthal genomes and ours were 99.5 percent identical, based on DNA extracted from three Croatian fossils. At an October conference in Cold Spring Harbor Laboratory in New York, Pääbo — a geneticist of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany — said the two species had sex, but it remained an open question as to whether children resulted and left a legacy in our genomes.
"It's a good, valid idea, and it needs to be examined," Harvati said. "Uncovering this could be vital to understanding our own origins."We are currently the only human species alive, but as recently as 24,000 years ago... more
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Rep. Alan Grayson discusses the Republican health care plan with Wolf Blitzer, Alex Castellanos and James Carville on CNN.
Says Republicans to the American people, "If you get sick, die quickly" WOW.
A democrat with balls finally!!! He should talk more.Rep. Alan Grayson discusses the Republican health care plan with Wolf Blitzer, Alex... more
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"Newly analyzed remains suggest that a modern human killed a Neanderthal man in what is now Iraq between 50,000 and 75,000 years ago. The finding is scant but tantalizing evidence for a theory that modern humans helped to kill off the Neanderthals.
"What we've got is a rib injury, with any number of scenarios that could explain it," said study researcher Steven Churchill, an associate professor of evolutionary anthropology at Duke University in North Carolina. "We're not suggesting there was a blitzkrieg, with modern humans marching across the land and executing the Neandertals [aka Neanderthals]. I want to say that loud and clear."
But he added, "We think the best explanation for this injury is a projectile weapon, and given who had those and who didn't, that implies at least one act of inter-species aggression."
Scientists are continuing to refine their understanding of early Homo sapiens and Neanderthals, with hopes of also resolving the mystery of how the latter species went extinct while we did not. Past research has yielded conflicting evidence on interbreeding between the two species, but the new study clearly shows the opposite of affection.
In fact, another Neanderthal skeleton dating back some 36,000 years and found in France showed signs of a scalp injury likely caused by a sharp object that may have been delivered by a modern human at the time, Churchill said.
"So if the Shanidar 3 case is also a case of inter-specific violence and if Shandiar 3 overlaps in time with modern humans, we're beginning to get a little bit of a pattern here," Churchill said.
Competition for resources with modern humans, along with other factors, may have also played a role in the die-off of Neanderthals, the researchers say."
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It certainly does tease the imagination to envision a showdown for survival between humans and another human-like species. Someone needs to make a badass movie about this pronto."Newly analyzed remains suggest that a modern human killed a Neanderthal man in... more
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Neanderthals could handle the weather, but they couldn't handle us, concludes a new analysis of late-Pleistocene hominid habitation.
Soon after modern humans arrived in Western Europe, plenty of temperate, food-rich habitat existed for our evolutionary near-brothers — but their settlements dwindled, and modern human settlements spread.
These patterns suggest that one of modern anthropological history's great mysteries had a harsh ending: a competition in which Neanderthals, for reasons still unknown, were doomed.Neanderthals could handle the weather, but they couldn't handle us, concludes a... more
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Most (ignorant but well meaning) people consider Neanderthal man, who lived up until around 25,000 years ago, to have been little more than a dumb cousin of homo sapiens (us).
However, studies of the stone instruments made by Neandethals indicates that despite their extinction (or perhaps sexual absorbtion into our species), their tools were just as effective as those of our ancestors.Most (ignorant but well meaning) people consider Neanderthal man, who lived up until... more
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DNA extracted from a 38,000-year-old Neanderthal bone has just enabled scientists to sequence the complete mitochondrial genome for the human-like species, according to a paper that will be published tomorrow in the journal Cell.
The remarkable feat, which has led to at least three major discoveries about the extinct stocky European individuals, represents a breakthrough for studies on the human family.
"This is the first complete mitochondrial genome sequence from an extinct hominid," lead author Richard Green explained to Discovery News.
Mitochondria, which an individual inherits from his or her mother, are cellular powerhouses that possess their own DNA and include 13 protein-coding genes. The researchers sequenced the Neanderthal mitochondria 35 times to ensure their findings were as accurate as possible.
After studying the newly completed genome, Green, a researcher at the Max-Planck Institute for Evolutionary Anthropology in Germany, and his team first concluded that the Neanderthal mitochondria falls outside the range of variation found in humans today, offering no evidence that interbreeding occurred between them and us.
The researchers are quick to add that such interbreeding could still have happened and that the Neanderthals' "exact relationship with modern humans remains a topic of debate."
Clearer is the fact that Neanderthals and humans split from a common ancestor around 660,000 years ago. The researchers based this initially upon prior research that determined humans and chimpanzees diverged from each other six to eight million years ago.
They calculated mtDNA sequence changes for both humans and Neanderthals since that time. These accumulated changes then "let us calculate how long ago was the most recent common ancestor of humans and Neanderthals," Green said.
He added, "This common ancestor likely looked something like Homo erectus." This extinct hominid is believed to have been super strong with a relatively large head and brain.
What most surprised the scientists was how little purification acted upon the Neanderthal's DNA, meaning that the elimination of slightly deleterious alleles, or variant gene forms, didn't occur very often within the population.
written by: Jennifer ViegasDNA extracted from a 38,000-year-old Neanderthal bone has just enabled scientists to... more
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