Two articles
May. 7th, 2010 12:31 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
conuly
One about how Neanderthals and Humans may have totally had hot, hot sex.
Signs of Neanderthals Mating With Humans
By NICHOLAS WADE
Neanderthals mated with some modern humans after all and left their imprint in the human genome, a team of biologists has reported in the first detailed analysis of the Neanderthal genetic sequence.
The biologists, led by Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have been slowly reconstructing the genome of Neanderthals, the stocky hunters that dominated Europe until 30,000 years ago, by extracting the fragments of DNA that still exist in their fossil bones. Just last year, when the biologists first announced that they had decoded the Neanderthal genome, they reported no significant evidence of interbreeding.
Scientists say they have recovered 60 percent of the genome so far and hope to complete it. By comparing that genome with those of various present day humans, the team concluded that about 1 percent to 4 percent of the genome of non-Africans today is derived from Neanderthals. But the Neanderthal DNA does not seem to have played a great role in human evolution, they said.
Experts believe that the Neanderthal genome sequence will be of extraordinary importance in understanding human evolutionary history since the two species split some 600,000 years ago.
So far, the team has identified only about 100 genes — surprisingly few — that have contributed to the evolution of modern humans since the split. The nature of the genes in humans that differ from those of Neanderthals is of particular interest because they bear on what it means to be human, or at least not Neanderthal. Some of the genes seem to be involved in cognitive function and others in bone structure.
“Seven years ago, I really thought that it would remain impossible in my lifetime to sequence the whole Neanderthal genome,” Dr. Paabo said at a news conference. But the Leipzig team’s second conclusion, that there was probably interbreeding between Neanderthals and modern humans before Europeans and Asians split, is being met with reserve by some archaeologists.
A degree of interbreeding between modern humans and Neanderthals in Europe would not be greatly surprising given that the species overlapped there from 44,000 years ago when modern humans first entered Europe to 30,000 years ago when the last Neanderthals fell extinct. Archaeologists have been debating for years whether the fossil record shows evidence of individuals with mixed features.
But the new analysis, which is based solely on genetics and statistical calculations, is more difficult to match with the archaeological record. The Leipzig scientists assert that the interbreeding did not occur in Europe but in the Middle East and at a much earlier period, some 100,000 to 60,000 years ago, before the modern human populations of Europe and East Asia split. There is much less archaeological evidence for an overlap between modern humans and Neanderthals at this time and place.
Dr. Paabo has pioneered the extraction and analysis of ancient DNA from fossil bones, overcoming daunting obstacles over the last 13 years in his pursuit of the Neanderthal genome. Perhaps the most serious is that most Neanderthal bones are extensively contaminated with modern human DNA, which is highly similar to Neanderthal DNA. The DNA he has analyzed comes from three small bones from the Vindija cave in Croatia.
“This is a fabulous achievement,” said Ian Tattersall, a paleontologist at the American Museum of Natural History in New York, referring to the draft Neanderthal genome that Dr. Paabo’s team describes in Thursday’s issue of Science.
But he and other archaeologists questioned some of the interpretations put forward by Dr. Paabo and his chief colleagues, Richard E. Green of the Leipzig institute, and David Reich of Harvard Medical School. Geneticists have been making increasingly valuable contributions to human prehistory, but their work depends heavily on complex mathematical statistics that make their arguments hard to follow. And the statistical insights, however informative, do not have the solidity of an archaeological fact.
“This is probably not the authors’ last word, and they are obviously groping to explain what they have found,” Dr. Tattersall said.
Richard Klein, a paleontologist at Stanford, said the authors’ theory of an early interbreeding episode did not seem to have taken full account of the archaeological background. “They are basically saying, ‘Here are our data, you have to accept it.’ But the little part I can judge seems to me to be problematic, so I have to worry about the rest,” he said.
In an earlier report on the Neanderthal genome, the reported DNA sequences were found by other geneticists to be extensively contaminated with human DNA. Dr. Paabo’s group has taken extra precautions but it remains to be seen how successful they have been, Dr. Klein said, especially as another group at the Leipzig institute, presumably using the same methods, has obtained results that Dr. Paabo said he could not confirm.
Dr. Paabo said that episode of human-Neanderthal breeding implied by Dr. Reich’s statistics most plausibly occurred “in the Middle East where the first modern humans appear before 100,000 years ago and there were Neanderthals until 60,000 years ago.” According to Dr. Klein, people in Africa expanded their range and reached just Israel during a warm period some 120,000 years ago. They retreated during a cold period some 80,000 years ago and were replaced by Neanderthals. It is not clear whether or not they overlapped with Neanderthals, he said.
These humans, in any case, were not fully modern and they did not expand from Africa, an episode that occurred some 30,000 years later. If there was any interbreeding, the flow of genes should have been both ways, Dr. Klein said, but Dr. Paabo’s group sees evidence for gene flow only from Neanderthals to modern humans.
The Leipzig group’s interbreeding theory would undercut the present belief that all human populations today draw from the same gene pool that existed a mere 50,000 years ago. “What we falsify here is the strong out-of-Africa hypothesis that everyone comes from the same population,” Dr. Paabo said.
In his and Dr. Reich’s view, Neanderthals interbred only with non-Africans, the people who left Africa, which would mean that non-Africans drew from a second gene pool not available to Africans.
And one about the AAP and female circumcision.
Apparently, the AAP is suggesting that instead of banning the procedure outright (and thus prompting families to send their girls back to Africa where the whole shebang can be done without any sort of sanitary equipment) that instead we allow a very minor version in a hospital.
I can actually see where they're coming from. They're saying that if people will do it anyway, better it be done safely. And I imagine they're thinking that by controlling this themselves they can make sure the most minor form of FGM is done instead of the most major.
Group Backs Ritual ‘Nick’ as Female Circumcision Option
By PAM BELLUCK
In a controversial change to a longstanding policy concerning the practice of female circumcision in some African and Asian cultures, the American Academy of Pediatrics is suggesting that American doctors be given permission to perform a ceremonial pinprick or “nick” on girls from these cultures if it would keep their families from sending them overseas for the full circumcision.
The academy’s committee on bioethics, in a policy statement last week, said some pediatricians had suggested that current federal law, which “makes criminal any nonmedical procedure performed on the genitals” of a girl in the United States, has had the unintended consequence of driving some families to take their daughters to other countries to undergo mutilation.
“It might be more effective if federal and state laws enabled pediatricians to reach out to families by offering a ritual nick as a possible compromise to avoid greater harm,” the group said.
But some opponents of female genital mutilation, or F.G.M., denounced the statement.
“I am sure the academy had only good intentions, but what their recommendation has done is only create confusion about whether F.G.M. is acceptable in any form, and it is the wrong step forward on how best to protect young women and girls,” said Representative Joseph Crowley, Democrat of New York, who recently introduced a bill to toughen federal law by making it a crime to take a girl overseas to be circumcised. “F.G.M. serves no medical purpose, and it is rightfully banned in the U.S.”
Georganne Chapin, executive director of an advocacy group called Intact America, said she was “astonished that a group of intelligent people did not see the utter slippery slope that we put physicians on” with the new policy statement. “How much blood will parents be satisfied with?”
She added: “There are countries in the world that allow wife beating, slavery and child abuse, but we don’t allow people to practice those customs in this country. We don’t let people have slavery a little bit because they’re going to do it anyway, or beat their wives a little bit because they’re going to do it anyway.”
A member of the academy’s bioethics committee, Dr. Lainie Friedman Ross, associate director of the MacLean Center for Clinical Medical Ethics at the University of Chicago, said the panel’s intent was to issue a “statement on safety in a culturally sensitive context.”
Dr. Friedman Ross said that the committee members “oppose all types of female genital cutting that impose risks or physical or psychological harm,” and consider the ritual nick “a last resort,” but that the nick is “supposed to be as benign as getting a girl’s ears pierced. It’s taking a pin and creating a drop of blood.”
She said the panel had heard anecdotes from worried doctors.
“If we just told parents, ‘No, this is wrong,’ our concern is they may take their daughters back to their home countries, where the procedure may be more extensive cutting and may even be done without anesthesia, with unsterilized knives or even glass,” she said. “A just-say-no policy may end up alienating these families, who are going to then find an alternative that will do more harm than good.”
Currently, more than 130 million women and girls worldwide have undergone female genital cutting, according to the American Congress of Obstetricians and Gynecologists. It is mostly performed on girls younger than 15 in countries including Ethiopia, Sudan and Somalia. Consequences can include severe complications with pregnancy, childbirth and sexual dysfunction.
The academy’s statement acknowledged that opponents of the procedure, “including women from African countries, strongly oppose any compromise that would legitimize even the most minimal procedure.”
Dr. Friedman Ross said, “If you medicalize it and say it’s permissible, is there a possibility that some people will misunderstand it and go beyond a nick? Yes.”
But she said the risk that people denied the ceremonial procedure, usually on the clitoris, would opt for the more harmful one was much more dangerous.
And the statement said that, “in some countries where FGC is common, some progress toward eradication or amelioration has been made by substituting ritual ‘nicks’ for more severe forms.”
Signs of Neanderthals Mating With Humans
By NICHOLAS WADE
Neanderthals mated with some modern humans after all and left their imprint in the human genome, a team of biologists has reported in the first detailed analysis of the Neanderthal genetic sequence.
The biologists, led by Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have been slowly reconstructing the genome of Neanderthals, the stocky hunters that dominated Europe until 30,000 years ago, by extracting the fragments of DNA that still exist in their fossil bones. Just last year, when the biologists first announced that they had decoded the Neanderthal genome, they reported no significant evidence of interbreeding.
Scientists say they have recovered 60 percent of the genome so far and hope to complete it. By comparing that genome with those of various present day humans, the team concluded that about 1 percent to 4 percent of the genome of non-Africans today is derived from Neanderthals. But the Neanderthal DNA does not seem to have played a great role in human evolution, they said.
Experts believe that the Neanderthal genome sequence will be of extraordinary importance in understanding human evolutionary history since the two species split some 600,000 years ago.
So far, the team has identified only about 100 genes — surprisingly few — that have contributed to the evolution of modern humans since the split. The nature of the genes in humans that differ from those of Neanderthals is of particular interest because they bear on what it means to be human, or at least not Neanderthal. Some of the genes seem to be involved in cognitive function and others in bone structure.
“Seven years ago, I really thought that it would remain impossible in my lifetime to sequence the whole Neanderthal genome,” Dr. Paabo said at a news conference. But the Leipzig team’s second conclusion, that there was probably interbreeding between Neanderthals and modern humans before Europeans and Asians split, is being met with reserve by some archaeologists.
A degree of interbreeding between modern humans and Neanderthals in Europe would not be greatly surprising given that the species overlapped there from 44,000 years ago when modern humans first entered Europe to 30,000 years ago when the last Neanderthals fell extinct. Archaeologists have been debating for years whether the fossil record shows evidence of individuals with mixed features.
But the new analysis, which is based solely on genetics and statistical calculations, is more difficult to match with the archaeological record. The Leipzig scientists assert that the interbreeding did not occur in Europe but in the Middle East and at a much earlier period, some 100,000 to 60,000 years ago, before the modern human populations of Europe and East Asia split. There is much less archaeological evidence for an overlap between modern humans and Neanderthals at this time and place.
Dr. Paabo has pioneered the extraction and analysis of ancient DNA from fossil bones, overcoming daunting obstacles over the last 13 years in his pursuit of the Neanderthal genome. Perhaps the most serious is that most Neanderthal bones are extensively contaminated with modern human DNA, which is highly similar to Neanderthal DNA. The DNA he has analyzed comes from three small bones from the Vindija cave in Croatia.
“This is a fabulous achievement,” said Ian Tattersall, a paleontologist at the American Museum of Natural History in New York, referring to the draft Neanderthal genome that Dr. Paabo’s team describes in Thursday’s issue of Science.
But he and other archaeologists questioned some of the interpretations put forward by Dr. Paabo and his chief colleagues, Richard E. Green of the Leipzig institute, and David Reich of Harvard Medical School. Geneticists have been making increasingly valuable contributions to human prehistory, but their work depends heavily on complex mathematical statistics that make their arguments hard to follow. And the statistical insights, however informative, do not have the solidity of an archaeological fact.
“This is probably not the authors’ last word, and they are obviously groping to explain what they have found,” Dr. Tattersall said.
Richard Klein, a paleontologist at Stanford, said the authors’ theory of an early interbreeding episode did not seem to have taken full account of the archaeological background. “They are basically saying, ‘Here are our data, you have to accept it.’ But the little part I can judge seems to me to be problematic, so I have to worry about the rest,” he said.
In an earlier report on the Neanderthal genome, the reported DNA sequences were found by other geneticists to be extensively contaminated with human DNA. Dr. Paabo’s group has taken extra precautions but it remains to be seen how successful they have been, Dr. Klein said, especially as another group at the Leipzig institute, presumably using the same methods, has obtained results that Dr. Paabo said he could not confirm.
Dr. Paabo said that episode of human-Neanderthal breeding implied by Dr. Reich’s statistics most plausibly occurred “in the Middle East where the first modern humans appear before 100,000 years ago and there were Neanderthals until 60,000 years ago.” According to Dr. Klein, people in Africa expanded their range and reached just Israel during a warm period some 120,000 years ago. They retreated during a cold period some 80,000 years ago and were replaced by Neanderthals. It is not clear whether or not they overlapped with Neanderthals, he said.
These humans, in any case, were not fully modern and they did not expand from Africa, an episode that occurred some 30,000 years later. If there was any interbreeding, the flow of genes should have been both ways, Dr. Klein said, but Dr. Paabo’s group sees evidence for gene flow only from Neanderthals to modern humans.
The Leipzig group’s interbreeding theory would undercut the present belief that all human populations today draw from the same gene pool that existed a mere 50,000 years ago. “What we falsify here is the strong out-of-Africa hypothesis that everyone comes from the same population,” Dr. Paabo said.
In his and Dr. Reich’s view, Neanderthals interbred only with non-Africans, the people who left Africa, which would mean that non-Africans drew from a second gene pool not available to Africans.
And one about the AAP and female circumcision.
Apparently, the AAP is suggesting that instead of banning the procedure outright (and thus prompting families to send their girls back to Africa where the whole shebang can be done without any sort of sanitary equipment) that instead we allow a very minor version in a hospital.
I can actually see where they're coming from. They're saying that if people will do it anyway, better it be done safely. And I imagine they're thinking that by controlling this themselves they can make sure the most minor form of FGM is done instead of the most major.
Group Backs Ritual ‘Nick’ as Female Circumcision Option
By PAM BELLUCK
In a controversial change to a longstanding policy concerning the practice of female circumcision in some African and Asian cultures, the American Academy of Pediatrics is suggesting that American doctors be given permission to perform a ceremonial pinprick or “nick” on girls from these cultures if it would keep their families from sending them overseas for the full circumcision.
The academy’s committee on bioethics, in a policy statement last week, said some pediatricians had suggested that current federal law, which “makes criminal any nonmedical procedure performed on the genitals” of a girl in the United States, has had the unintended consequence of driving some families to take their daughters to other countries to undergo mutilation.
“It might be more effective if federal and state laws enabled pediatricians to reach out to families by offering a ritual nick as a possible compromise to avoid greater harm,” the group said.
But some opponents of female genital mutilation, or F.G.M., denounced the statement.
“I am sure the academy had only good intentions, but what their recommendation has done is only create confusion about whether F.G.M. is acceptable in any form, and it is the wrong step forward on how best to protect young women and girls,” said Representative Joseph Crowley, Democrat of New York, who recently introduced a bill to toughen federal law by making it a crime to take a girl overseas to be circumcised. “F.G.M. serves no medical purpose, and it is rightfully banned in the U.S.”
Georganne Chapin, executive director of an advocacy group called Intact America, said she was “astonished that a group of intelligent people did not see the utter slippery slope that we put physicians on” with the new policy statement. “How much blood will parents be satisfied with?”
She added: “There are countries in the world that allow wife beating, slavery and child abuse, but we don’t allow people to practice those customs in this country. We don’t let people have slavery a little bit because they’re going to do it anyway, or beat their wives a little bit because they’re going to do it anyway.”
A member of the academy’s bioethics committee, Dr. Lainie Friedman Ross, associate director of the MacLean Center for Clinical Medical Ethics at the University of Chicago, said the panel’s intent was to issue a “statement on safety in a culturally sensitive context.”
Dr. Friedman Ross said that the committee members “oppose all types of female genital cutting that impose risks or physical or psychological harm,” and consider the ritual nick “a last resort,” but that the nick is “supposed to be as benign as getting a girl’s ears pierced. It’s taking a pin and creating a drop of blood.”
She said the panel had heard anecdotes from worried doctors.
“If we just told parents, ‘No, this is wrong,’ our concern is they may take their daughters back to their home countries, where the procedure may be more extensive cutting and may even be done without anesthesia, with unsterilized knives or even glass,” she said. “A just-say-no policy may end up alienating these families, who are going to then find an alternative that will do more harm than good.”
Currently, more than 130 million women and girls worldwide have undergone female genital cutting, according to the American Congress of Obstetricians and Gynecologists. It is mostly performed on girls younger than 15 in countries including Ethiopia, Sudan and Somalia. Consequences can include severe complications with pregnancy, childbirth and sexual dysfunction.
The academy’s statement acknowledged that opponents of the procedure, “including women from African countries, strongly oppose any compromise that would legitimize even the most minimal procedure.”
Dr. Friedman Ross said, “If you medicalize it and say it’s permissible, is there a possibility that some people will misunderstand it and go beyond a nick? Yes.”
But she said the risk that people denied the ceremonial procedure, usually on the clitoris, would opt for the more harmful one was much more dangerous.
And the statement said that, “in some countries where FGC is common, some progress toward eradication or amelioration has been made by substituting ritual ‘nicks’ for more severe forms.”
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no subject
Date: 2010-05-07 04:47 pm (UTC)no subject
Date: 2010-05-07 04:53 pm (UTC)no subject
Date: 2010-05-07 06:05 pm (UTC)Also, thank you. I think if a ceremonial nick saves even one girl from genital mutilation, it's justified itself.
no subject
Date: 2010-05-07 07:17 pm (UTC)And yes, I think in this case - assuming I'm reading their suggestion correctly - it's definitely a case of the lesser of two evils.
no subject
Date: 2010-05-07 06:49 pm (UTC)Because if it's a boy, it's all okay...
I agree that if it satifies a religious need while mitigating very real potential harm otherwise, go for it, though I will ever and always argue that the religious need is false and physically harmful - for girls or boys.
no subject
Date: 2010-05-07 07:18 pm (UTC)Indeed. But let's not start that.
no subject
Date: 2010-05-07 08:09 pm (UTC)no subject
Date: 2010-05-07 08:20 pm (UTC)no subject
Date: 2010-05-07 10:44 pm (UTC)I should take my steam somewhere else... I've got a serious axe to grind on this issue.
no subject
Date: 2010-05-07 11:09 pm (UTC)no subject
Date: 2010-05-08 12:11 am (UTC)It just makes my head explode so I'll stop now.
no subject
Date: 2010-05-23 07:06 am (UTC)