Human Ancestors Interbred with Related Species

Matt Kaplan, Nature News, September 5, 2011

Our ancestors bred with other species in the Homo genus, according to a study published today in the Proceedings of the National Academy of Sciences. The authors say that up to 2% of the genomes of some modern African populations may originally come from a closely related species.

Palaeontologists have long wondered whether modern humans came from a single, genetically isolated population of hominins or whether we are a genetic mix of various hominin species.

{snip}

It has been a mystery whether similar genetic mixing [to that of non-Africans and Neanderthals] took place among Homo species even earlier, before the populations that became modern humans left Africa.

To find out, evolutionary biologist Michael Hammer at the University of Arizona in Tucson and his colleagues studied DNA from two African hunter-gatherer groups, the Biaka Pygmies and the San, as well as from a West African agricultural population known as the Mandenka.

{snip}

To find signs of infiltration from other Homo species, the researchers looked at 61 non-coding DNA regions in all three groups. Because direct comparison to archaic specimens wasn’t possible, the authors used computer models to simulate how infiltration from different populations might have affected patterns of variation within modern genomes.

Then they looked for such patterns of variation in the DNA of the three African populations. On chromosomes 4, 13 and 18, the researchers found genetic regions that were more divergent on average than known modern sequences at the same locations, hinting at a different origin.

{snip}

Hammer and his colleagues argue that roughly 2% of the genetic material found in these modern African populations was inserted into the human genome some 35,000 years ago. They say these sequences must have come from a now-extinct member of the Homo genus that broke away from the modern human lineage around 700,000 years ago.

Hammer says this disproves the conventional view that we are descended from a single population that arose in Africa and replaced all other Homo species without interbreeding. “We need to modify the standard model of human origins,” he says.

Geneticist Sarah Tishkoff, who studies population genetics and human evolution at the University of Pennsylvania in Philadelphia, is more cautious. “This raises the possibility that there may have been ancient admixture with archaic populations,” she says.

{snip}


Michael F. Hammer et al., PNAS, September 6, 2011

Abstract:

A long-debated question concerns the fate of archaic forms of the genus Homo: did they go extinct without interbreeding with anatomically modern humans, or are their genes present in contemporary populations? This question is typically focused on the genetic contribution of archaic forms outside of Africa. Here we use DNA sequence data gathered from 61 noncoding autosomal regions in a sample of three sub-Saharan African populations (Mandenka, Biaka, and San) to test models of African archaic admixture. We use two complementary approximate-likelihood approaches and a model of human evolution that involves recent population structure, with and without gene flow from an archaic population. Extensive simulation results reject the null model of no admixture and allow us to infer that contemporary African populations contain a small proportion of genetic material (≈2%) that introgressed ≈35 kya from an archaic population that split from the ancestors of anatomically modern humans ≈700 kya. Three candidate regions showing deep haplotype divergence, unusual patterns of linkage disequilibrium, and small basal clade size are identified and the distributions of introgressive haplotypes surveyed in a sample of populations from across sub-Saharan Africa. One candidate locus with an unusual segment of DNA that extends for >31 kb on chromosome 4 seems to have introgressed into modern Africans from a now-extinct taxon that may have lived in central Africa. Taken together our results suggest that polymorphisms present in extant populations introgressed via relatively recent interbreeding with hominin forms that diverged from the ancestors of modern humans in the Lower-Middle Pleistocene.

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  • Anonymous

    We live in a meaningless society, this means nothing, Unless they can manipulate it into propaganda for their votes…. then it would be a world breakthrough in science.

  • Peejay in Frisco

    As I have posted earlier,black homo sapiens have interbred with every pre Homo Erectus species ever since we have genetically separated from Chimpanzees. This explains their one of a kind behavior.

  • idareya

    “Because direct comparison to archaic specimens wasn’t possible, the authors used computer models to simulate how infiltration from different populations might have affected patterns of variation within modern genomes.”

    And the computer models contain all the biases and political correctness contained in the people who created them.

  • Wayne Engle

    With all the scientific mumbo-jumbo boiled out of it, what this finding means is: Black Africans may have some ape genes. It’s possible; we all know that.

    But look for the rest of the scientific community to do an elephant walk all over these findings. I can hear the screams of “Racism!” and “Racial stereotypes!” now. Which doesn’t mean it’s not true. And it might explain a lot of things, mightn’t it?

  • Hirsch

    How is the left going to be able to spin all of the rapidly accruing evidence that flies in the face of their arguments? Those who say that the human races are not subspecies might actually be right this time. It turns out that we are virtually different species!

    When one considers the very minor differences that cause enough friction for civil war to break out (Sunnis and Shiite, Protestant and Catholic) it would appear that having blacks, whites, Hispanics, and Asians cluster around one another is a recipe for terrible bloodshed.

    Separatists and nationalists are struggling to avoid a horrible letting of blood that is coming our way if we continue to mix our minorities among each other, a la the former Yugoslovia. American exceptionalism or no, it can happen here.

  • Anonymous

    “With all the scientific mumbo-jumbo boiled out of it, what this finding means is: Black Africans may have some ape genes. It’s possible; we all know that.”

    Actually the study found possible evidence of archaic admixture in pygmies and Khoisan people, with little or none found in West African/Bantu negroid populations. The only negroid groups with evidence of this admixture were groups like southern Bantus who have known admixture from Khoisan.

    And no one is suggesting that anyone bred with apes, which is absurd.

  • Kenelm Digby

    Actually, the book ‘Erectus Walks Amongst Us’, (which is available on the web), postulated this theory years ago – when this theory was distinctly disregarded by the anthropological establishment.

  • OldEuropean

    Interesting article about the same topic:

    http://goo.gl/EPQTf

  • sshadow

    To give an idea of how much genetic difference 2% really is, it is instructive to contrast this study with a Chimpanzee genome sequencing effort led by Dr Eric S Lander in the early 2000s. They found that a Chimp is almost 99% similar in DNA structure to modern humans. The entire genetic code is 3 billion bits. The 1% difference is greater than you think. Some numbers are as follows:

    ” By placing the two codes alongside each other, scientists identified all 40 million molecular changes that today separate the two species and pinpointed the mere 250,000 that seem most responsible for the difference between chimpness and humanness.”

    It is known that Pygmy’s IQ is about 60. That means that many have an IQ closer to 45. They look human, much as subspecies of dogs look like dogs. Clearly, they are a subspecies, and if the cultural Marxists didn’t have such absolute control of academia they would, without any be drama, be called that.

    If this genetic material was inserted 35000 years ago, it would have been long after the departure of our ancestors emerged from Africa, if indeed that is the way it happened. The number of differences in the quotes above are mind boggling, and allow for major differences in appearance, instincts, intellect, personality, humor and likes and dislikes. Placing them in our schools would be doomed to failure. They would need an institutional setting in our society, but not in theirs. Look at the current video with black faces on Politcal Cesspool (blog) for food for thought.

  • Fr. John

    I’m so DONE with all this, ‘We’re one race, the human race’ folderol.

    As a cleric, I know that God created Adam as a special creation. Whether than took place in six twenty-four hour days, or over six billion years, doesn’t really matter much to me. And I also know, believe, and teach, that only that Adamic Humanity is the object of God’s favor, as the Bible clearly teaches, and as Christ supported.

    What DOES matter in the halls of pseudo-science, (which is merely another, satanic religion) is that neither the ‘out of Africa’ crowd (on the evolutionary side, starting with Leakey in the 1970’s) or the ‘all races derive from Adam, via Shem, Ham, and Japheth’ ICR, nutso-creationist crowd, are correct. For they BOTH posit a ‘universal jurisdiction’ mentality that equates the black with my ‘brother,’ and I refuse to go there- for once and for all. SO did the Church, clearly before AD 1054, and reluctantly, only after AD 1860.

    Clearly, anthropological evidence suggests a number of things, all of which can be held as a Christian of European descent. One- that Neanderthals are in actuality, the forerunners of the modern Jew- we have this clearly noted by (part) Jewish author Michael Bradley, and his ‘Iceman Inheritance.’ Thus, the reason for ‘interbreeding’ among Homo Sapiens Sapiens and the Neanderthals, is because of this people.

    http://www.michaelbradley.info/books/iceman/iceman_promo.html

    Next, the sudden and almost miraculous (!) appearance of Caucasoid humanity, along with the fully-developed civilizations, @7-10,000 years ago, is NEVER EXPLAINED by these same [sic] ‘scientists.’ How could they? It would ruin their ‘worship of the black as their new god’ with the ‘creation myth’ of ‘Out of Africa’!!!

    As Jewish author Gerald Schroeder noted in his overlooked book, ‘The Science of God,’ could it have been YHWH God who perfected the ‘ultimate creation’ of Adam, on the ‘sixth’ day/age, as being both intellectually (and ontologically) differing and different from all other preceding hominids, that formed our entire Western Civilization? Of course HE did!

    The question, ladies and gentlemen, is one of RELIGION, not ‘science.’ I believe in the religion of the Hebrew Monotheists, given Incarnation in the person and race of Christ, as the “Second ADAM.”

    Leakey, Gould, Hawking, and all the other ‘Black Worshippers’ merely worship an idol of their own making, and have made up myths to corroborate their fallacious facts.

    http://goo.gl/U3JML

  • highduke

    Correct me if I’m wrong but isn’t it possible that these markers could be present in Eurasians as well since they only tested 3 Black populations and no others?

  • Jeddermann.

    “it would appear that having blacks, whites, Hispanics, and Asians cluster around one another is a recipe for terrible bloodshed.”

    “Separatists and nationalists are struggling to avoid a horrible letting of blood that is coming our way if we continue to mix our minorities among each other, a la the former Yugoslovia. American exceptionalism or no, it can happen”

    It is a bad idea to mix anywhere in any way. If it as possible then it would have been done a long time ago. But we see few if any examples if different groups living in the same spot and both thriving in harmony. AND if in those instances where it seems to work, it is a mirage. Normally on as in a Yugoslavia where you have a totalitarian or very authoritarian that make the groups “get along” by very rigid and strong governmental action. But beneath the surface there is the existing tension and anger and give it a chance to “surface” and you have problems.

    I am fond of telling folks that back in the early 1970’s the liberal used to point to three nations around the world and use those as models to lecture the American of how differing groups could “get together” in the same space. These three nations were Yugoslavia, Sri Lanka [Ceylon] and Lebanon. That of course, BEFORE all three nations blew up almost literally in violence and civil war of the worst possible nature. The good old liberal always has it so right.

  • Jeddermann.

    “The authors say that up to 2% of the genomes of some modern African populations may originally come from a closely related species.”

    Hominid species NOT all that unlike humans, but not modern humans. The “Out of Africa” theory as I understand it says that first modern humans LEFT Africa and then spread out over the earth and THEN at a later date returned to Africa and spread over the entire continent ONLY after many thousands or tens of thousands of years of wandering. So variation of course must have occurred during that period.

  • GH

    “About 13% of the sub-Saharan gene pool comes from an earlier expansion of pre-modern hominins that occurred c. 111,000 years ago”

    “It is common to distinguish between Africans and non-Africans, with the former being much more genetically diverse than the latter. But, the real “gap” in human origins seems to be between the really old Africans (“Paleoafricans”) and the rest (“Afrasians”).

    The Paleoafrican element is entirely confined to Africa, while the Afrasian one is found in both Africa and Eurasia. Indeed, modern humans can be entirely split into two groups: (i) a group of “pure” Afrasians which includes all non-Africans, and (ii) a group of Afrasian-Paleoafricans which includes all non-Caucasoid Africans. ”

    http://evoandproud.blogspot.com/2010/05/archaic-admixture-in-africans.html

  • ben tillman

    “Human Ancestors Interbred with Related Species”

    That’s a stupid headline. Those so-called “related species” are also “human ancestors”.

  • Jim

    Sure, the pc hall monitors will try to downplay the mounting genetic evidence for sub-Saharan black Africans being fundamentally different from the rest of humanity, but at least some scientists are discussing it. What happened to “We’re all exactly the same except for skin color,” or “Race is a social construction”? Science will have the final word.

  • Anonymous

    Posts 1,3,7

    It appears that within the last three or four decades the story of human origins has been subject to “trophy seeking” science that neglects the less likely possibilities (and sometimes the less politically correct possibilities) in order to cultivate a focus of “discovery”??

  • Ken

    The modern genus/species labels have been taken for quite a ride recently being that we know all kinds of species can interbreed. In order to correct the labels they’d have to rewrite a lot of scientific literature lol. I still don’t get why they had to add another “sapiens” to the end of Homo Sapiens, I suppose they did that when they found out neanderthals and homo sapiens were interbreeding? Or did the “society for socially responsible sciences” decide to add the other sapiens as not to allow any room for the scientifically factual subspecies called RACE?

  • William

    When we read statments such as “the chimpanzee shares 98.6% of human DNA” or “the human race(s) share 99.2% common DNA” one should consider that we are about 98% the same as a dog and 80% the same as an oyster. Most DNA codes for proteins all living creatures have in common.

    Some sequences, minor though they many be, make big differences in morphology, brain size or even having a brain.

    It would be like saying Diken’s novel “A tail of two cities” was the same as “Moby Dick” because 98% of the words are the same.

    Ludwig Prandtl’s translated treatise on the boundary layer within liquids would probably be 70% the same as “Pride and Prejudice” differing in the absence of words such as “Miss Bennet” and “Mr Darcy” and “Helmholz Vortex”

    It’s like having 1000lbs of ducuments on how to mine, log, refine, manufacture timber beams, bricks, tiles, synthetic carpet, manufacture cable but not noting that its only about 20 pages decide what the kind of house or office you are going to get.

  • Publius

    Wow!

    Please keep us posted with developments. This bolsters the Multi-regional hypothesis, that has been advocated by many anthropologists, most notably, Carl Coon.

  • Anonymous

    Ref. posts 17,20

    The multi-regionalists at Ann Arbor always insisted their viewpoint was quite distinct from that of Carleton S. Coon.

    However, while the Out of Africa model has been mentioned eagerly in about all undergradute classes in America in which

    it would have relevance, most undergrads have never heard in

    the classroom any cognizance given to multi-regionalism–let alone mention of Carleton S. Coon. BTW, Coon’s ORIGIN OF RACES is seen in part of Eastern Europe as still having a good pulse beat.

  • Anonymous

    Re. 17,20,21

    I don’t recall from the presentations made at the AR Conferences

    in the 90’s, any presentation that would be directly relevant to this topic that contained anything except explicit and implicit endorsement of a whole-hog Out of Africa model. (?) Well before 1994, Mankind Quarterly had contained some sidebar reservations about a whole-hog OoA model. From a deductive standpoint, it would seem far-fetched indeed that OoA migrants would not have encoutered along the way those with whom they were interfertile.