This may be one of my favorite science stories in years. Researchers have concluded that the “superathlete” gene that helps Sherpas and other Tibetans thrive at high altitudes is actually traced to an ancient species of human, the Denisovans. The gene, EPAS1, regulates the body’s production of hemoglobin, and was acquired from the Denisovans. Of course, the Denisovans went extinct some 40,000 years ago so for those creationists who insist that the Earth is only a few thousand years old . . . you might want to move on to the next story.
The Denisovans mated with the ancestors of Europeans and Asians and then disappeared. The researchers focused on a difference between Sherpas and other high-altitude people like Andean highlanders who have adapted to thin air in a way that adds more oxygen-carrying hemoglobin to their blood. However, Tibetans have less hemoglobin in their blood, which avoids some problems like clots and strokes. The reason appears to be the Denisovans. The ancestors of Tibetans and Han Chinese got the gene when they mated with Denisovans. However, many of the descendants did not need the gene and eventually lost the EPAS1. However, it was the Tibetans who settled on the high-altitude Tibetan plateau and therefore favored the genes’ continuation.
Very cool.
Source: Science Mag
Karen S wrote “Neanderthals … their tools were less advanced”
You are wrong. Read either of the below stories. The earlier is from 2008, so you have been ignoring this story for many years.
BBC News:
– Neanderthals were able to ‘develop their own tools’
– ‘Complexity’ of Neanderthal tools
Karen S wrote “Neanderthals … lacked the vocal apparatus for the complex vocal language of Homo sapiens”
Wrong again. Read below.
BBC News:
– Neanderthals could speak like modern humans, study suggests
Only a very short time ago, Homo sapiens and Neanderthals were thought to have inhabited completely separate logical trees. We thought that the former was superior in every way to the brutish ways of the latter. We thought that Neanderthals were either killed or out-competed by Homo sapiens. But now we know that this is all wrong.
You can drone on about subspecies and hybrids all you want, but the science is evolving very quickly. You continue to ignore that people with 100% African ancestry are somewhat different than people with Neanderthal DNA and those with Denisovian DNA. Does that make the second two subspecies or hybrids? I have no idea, but as JT’s original article noted, the science is starting to explain some of the differences between races. There is much more to come.
P.S. Ever read the Bell Curve? The one sentence summary is that people with 100% African ancestry have an IQ of 85 as compared to Europeans which have one of 100. Jews have an IQ of 105 and East Asians have one slightly higher than Europeans (101 or 102, I think). People with half African and half European ancestry have an IQ halfway between 85 and 100. This was astoundingly politically incorrect when it was released and no doubt the critics had a valid point when they noted that poverty has a significantly negative effect on intelligence. That said, non-Africans having a significant portion of Neanderthal and/or Denisovian DNA is likely to be the reason for the difference.
http://www.udel.edu/educ/gottfredson/reprints/1997mainstream.pdf
Paul – talk about minority status!
We have recreated species that look similar through breeding different species that are either the closest living relatives, or had the physical traits desired, but have not been able to reclaim the exact similar species. There have been efforts to recreate lost breeds of poultry, for example, that were carried out by breeding individuals with the traits they were trying to recreate. But they could not revive that actual breed, just something that looked like it. And that is WITHIN a species.
If coyotes became extinct, we’d try working backwards from coyote wolf hybrids. We’d have a bottlenecked population, and we’d keep breeding the individuals that looked the most like coyotes. In the end, we’d be able to breed a coyote look in much the same way we’ve bred dogs to any shape we desire, but it would not be a pure coyote.
If we lost wolves, we’d still have silver German Shepherd Dogs, but we cannot turn back the evolutionary clock . . . yet. One day we might be able to genetically engineer an extinct species from a DNA sample. The Jurassic Park movie is theoretically possible.
We could not recreate Neanderthals because we only have 1-5% of DNA in individuals to work with. The rest is completely lost. Unless we have intact DNA from a Neanderthal and genetically clone him or her. That is the ONLY way we could retrieve the lost DNA that I know of.
By your logic, none of the ancient species that evolved to form Homo sapiens sapiens went extinct because fragments of their DNA exist in modern humans.
So there are millions of Homo heidelbergensis in existence today? Paleontologists will be thrilled. And we’ll no longer need the Endangered Species Act. As long as there are wolf hybrids somewhere, the Red Wolf cannot go extinct. And that’s wonderful news that the Dire wolf is still in existence through fragments of DNA.
Karen – do think northern Europeans (those with blue eyes) apply for protection under the Endangered Species Act?
This conversation on the evolution of man definitely turned in a different direction than I could have predicted. I am really surprised by your statements.
“Don’t compare dogs and humans.” What other examples can I give you to explain biology in the present day? There are no other species of humans that exist with us in the present day that I can use to explain hybrids and conspecificity.
Saucy:
You are misunderstanding the biology.
Hybrids can become integrated within a species. I have already explained about coyotes (canis latrans) and wolves interbreeding with fertile offspring, and yet they are still considered different species, not subspecies. In addition, ligers and tigons are crosses between Panthero leo and Panthera tigeris which are fertile. And yet there is no doubt that lions and tigers are different species.
There are no living representatives of Neanderthals. There are zero pure Neanderthals, regardless of the 1% of their DNA which exists in part of the population of Homo sapiens sapiens.
Much can be learned about Neanderthals. What we do know is that they lacked the vocal apparatus for the complex vocal language of Homo sapiens sapiens, and their tools were less advanced. That does not mean they did not have a rich culture.
We evolved from different ancestral species which also died out. There are no more Homo heidelbergensis from which we likely evolved. Even though we share some genetic components, there are zero Homo heidelbergensis on this Earth.
“Ever wonder why African music, including rap, is all rhythm-based, while Europe was the birthplace of classical music? I bet classical music was a Neanderthal contribution.” Please clarify – are you trying to say that Neanderthals were a different subspecies, rather than a different species (as their taxonomic name and the entire scientific community asserts?) If Neanderthals were a different subspecies that you claim never went extinct because there was some interbreeding with Homo sapiens sapiens, then you are saying that a population with any Neanderthal DNA is a different subspecies than a population without it. Your reference to the different music of Africa compared with Europe, and your supposition that classical music must be a Neanderthal contribution, appears to say that Africans and non-Africans are different subspecies.
I could not disagree more strongly with you. The scientific community disagrees with you.
It’s marvelous to inherit blue eyes from a distant hybrid, as well as other sources of mutations, because it offers a glimpse into our distant past. But it does not make you a different subspecies than those without blue eyes.
DNA similarities can be found across all species. The Red Wolf and the coyote share many DNA traits. So one cannot say that there is no tiny fragment of Dodo DNA on Earth in any living bird. Actually, the Nicobar pigeon is its closest living relative.
If coyotes were completely wiped out, we would not claim that they did not go extinct because certain populations of the grey wolf are about 5% coyote.
Karen – we have been able to breed back species.
Karen S wrote “Actually, Neanderthals and Denisovians ARE different species”
I was referring to the comparison of current humans and Neanderthals. I am European-American and therefore have 1-4% of Neanderthal DNA in me because my ancestors, a mix of African humans (homo sapiens) and Neanderthals (homo neanderthalensis) played the two-backed beast. Blue eyes came from Neanderthals. I have blue eyes. Therefore the part of me that is Neanderthal is not trivial.
By the way, we have only found one finger bone fragment, two teeth, and one toe bone of Denisovian people, so we will have more to discover.
“There are zero individuals with pure Homo neanderthalensis DNA, making their species extinct.”
You and JT are using terminology incorrectly. The dodo bird is extinct because all examples died. Their family tree reached an end. Its DNA is not to be found anywhere except in stuffed birds in museums.
But Neanderthals did NOT die off. They and Denisovians interbred with African humans. Their family trees did not end. One of my ancestors was a Neanderthal. Tibetans have Denisovian ancestors.
A typical definition of the word “extinct” is, “having died out leaving no living representatives,” but that is not the case here. Are your great-great-grandparents extinct or merely dead?
“Typically, hybrids are less fit, even if they are fertile”
Don’t compare dogs and humans; studies on mice do not remotely always transfer to higher-level mammals. At the risk of being highly politically incorrect, African humans and Neanderthals each donated some very valuable traits, making non-African offspring MORE likely to survive. The old thinking that Neanderthals were clumsy, stupid oafs has been proven to be wrong (sophisticated tools have been found). Ever wonder why African music, including rap, is all rhythm-based, while Europe was the birthplace of classical music? I bet classical music was a Neanderthal contribution.
P.S. We discovered Neanderthal and Denisovian DNA in non-African people only just recently. Some scientists believe there is another homo population yet to be discovered that contributed to Asian DNA. That’s the problem with anthropology: we are making educated guesses based on the fossils we find. More is to come.
As another example, wolves and dogs can interbreed and create viable offspring. But no one would say there is no need to protect the grey wolf from extinction because some wolf-dog hybrids exist. Or say that as long as some wolf DNA gets incorporated through hybrid interbreeding, or they share enough DNA with canid lupus familiars, there is no need to save the species.
Typically, hybrids are less fit, even if they are fertile. Coyotes are smaller than wolves, and have evolved very specific, solitary hunting tactics. Wolves are larger, and hunt in packs. Hybrids are in between, and sometimes have conflicting instincts.
Another example is the Red Wolf and the coyote. They are 2 different species, but share a fairly recent common ancestor. They, like dogs, can interbreed and create fertile offspring. The integration of too many hybrids into a population so small as the Red Wolf could threaten its viability by introducing conflicting instincts.
So the existence of hybrids does not prove conspecificity (belonging to the same species.)
Although the inability to breed and produce fertile offspring proves they are different species, the ability to produce fertile hybrids does not disprove it by itself.
There are zero individuals with pure Homo neanderthalensis DNA, making their species extinct.
Saucy:
Actually, Neanderthals and Denisovians ARE different species. We are Homo sapiens sapiens, and Neanderthals are Homo neanderthalensis. I believe they are our closes living relative.
Not everyone has Neanderthal DNA. And some individuals have more than others.
When coyotes breed with grey wolves, grey wolves do not go extinct, or they are not suddenly considered one species (even though they were closely related enough to produce fertile offspring.) But DNA analysis of the grey wolf population shows a certain % of subjects will have some coyote genes.
The tiny remnants of Neanderthal DNA in some of our chromosomes are like an arc with tantalizing bits of their genetic code.
Hahaha, gene and tonic, good one Dredd.
I’ll have a gene and Tonic please …
Karen S wrote “I recall the Eve paper assumed that any other female contemporaries did not have surviving lines”
I cannot comment on your article because I did not read it. But I think some reporters completely misunderstood what the scientists were saying. Essentially they declared that there is one woman who had an unbroken string of girls through the years. That’s an amazing string in itself, but it is not at all the same as saying that all living people have her as an ancestor. I suspect some people jumped on the story because it appeared to confirm that the biblical story of Adam and Eve is true, but it did no such thing.
“Neanderthals and Denisovans are different species of humans”
No. That’s what we used to think, that Neanderthals died out in competition with African humans. Neanderthals and Denisovans interbred with African humans and produced the Europeans and Asians of today. Most people have not realized just how important these findings are.
As Pogo said long ago: we have met the enemy and he is us.
“Our common ancestor from which these different species of humans evolved would be much further back”
Yes, at least 400,000 years back.
Our common ancestor from which these different species of humans evolved would be much further back.
Neanderthals and Denisovans are different species of humans, so they would not share a Mitochondrial Eve with homo sapiens.
Thanks, Saucy – I read the Neanderthal article long after the Eve mitochondrial analysis. I recall the Eve paper assumed that any other female contemporaries did not have surviving lines.
Karen S wrote “I think it’s amazing that we were able to trace our ancestry back to a single female ancestor, an Eve, through mitochondrial DNA analysis”
You are misinterpreting the science. Read the National Geographic article “Why Am I Neanderthal?” (genographic.nationalgeographic.com/neanderthal). It states that Neanderthals and Denisovans are believed to have left Africa between 300,000 to 400,000 years ago. However, Mitochondrial Eve lived between 100,000 to 200,000 years ago in Africa. And then read the Wikipedia article on Mitochondrial Eve, especially the part where it states: “However, nuclear DNA studies indicate that the size of the ancient human population never dropped below tens of thousands. Other women living during Eve’s time have descendants alive today, but at some point in the past each of their lines of descent did not produce a female, thereby breaking the mitochondrial DNA lines of descent.”
The difficulty I have is when people use the Bible as a science book. It was never intended to be a science book. If Jesus preached about genes, gravity, orbits, or quantum physics, we never would have heard of Him because He would have been immediately stoned.
I think it’s amazing that we were able to trace our ancestry back to a single female ancestor, an Eve, through mitochondrial DNA analysis. And Einstein proved that matter is energy. And light behaves as both a particle and a wave.
But my faith in God is does not interfere with my love of science. I believe in God and spirituality, and that belief is in no way threatened by any scientific discovery.
It’s so neat when biology, anthropology, and paleontology all collide.
Neanderthals and Cro Magnon man also blended, as well, and light European skin can be traced to a Neanderthal gene. Neanderthals had been in colder climates with weaker sunlight longer and had already adapted lighter skins.
There is a grim inference, however, to these origins of blended genes. When a species of human goes extinct for any reason other than a natural disaster (like the Clovis Indians suffered), one can assume that there were some sorts of clashes or tension between them and the species that emerged victorious and survived. Anthroplogists generally assume such blending of clans mostly do not occur through happy intermarriages.
JT wrote “the Denisovans went extinct some 40,000 years ago”
The word “extinct” implies that Denisovans went the way of the Dodo bird, i.e. there is no trace of them except in museums. On the contrary, Denisovans and Neanderthals interbred with humans leaving Africa and were assimilated into the gene pool, as I wrote above. For people of Asian and European heritage, Denisovans and Neanderthals are ancestors. Search on “Denisovan Neanderthal” for many interesting stories.