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lgmayka
12-16-2013, 02:56 AM
Phys.org covers the controversial hypothesis that the human race is, to a slight extent, an ape-pig hybrid:

Initial article covering the hypothesis (http://phys.org/news/2013-07-chimp-pig-hybrid-humans.html)
Followup article (http://phys.org/news/2013-07-human-hybrids-closer-theory-evidence.html)

The author of the hypothesis has a PhD in genetics (http://www.macroevolution.net/human-origins.html#.Uq5p8fRDtpk), but he is (suspiciously?) pessimistic about finding genetic evidence for his hypothesis (http://www.macroevolution.net/hybrid-hypothesis-section-6.html#.Uq5H6vRDtpk).

An article describing full sequencing of the pig genome (http://www.nature.com/nature/journal/v491/n7424/full/nature11622.html) does not mention any unexpected similarity to that of humans.

But we must always be prepared for the unexpected (http://www.newscientist.com/article/dn4558-pighuman-chimeras-contain-cell-surprise.html#.Uq5WTfRDtpk):
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Pigs grown from fetuses into which human stem cells were injected have surprised scientists by having cells in which the DNA from the two species is mixed at the most intimate level.

It is the first time such fused cells have been seen in living creatures.
...
The adult pigs that had received human stem cells as fetuses were found to have pig cells, human cells and the hybrid cells in their blood and organs.

"What we found was completely unexpected. We found that the human and pig cells had totally fused in the animals' bodies," said Jeffrey Platt, director of the Mayo Clinic Transplantation Biology Program.

The hybrid cells had both human and pig surface markers. But, most surprisingly, the hybrid cell nuclei were found to have chromosomal DNA that contained both human and pig genes. The researchers found that about 60 per cent of the animals' non-pig cells were hybrids, with the remainder being fully human.
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Needless to say, I do not necessarily approve of such experimentation; I am only reporting it.

Táltos
12-16-2013, 04:22 AM
Interesting, but maybe should not be too surprising. Pork insulin structurally is very close to human insulin. It is off by one amino acid. http://www.idf.org/about-insulin-0
Yikes! Maybe there is something to that Ancient Aliens show that I so like to watch. They ponder about the "hybrid" Gods found in ancient Egypt. :biggrin1: For the record I don't approve of messing with Mother Nature either.

AJL
12-16-2013, 04:33 PM
I guess this would best be thought of as parallel evolution. Hippos bear a number of morphological similarities to pigs as well but are more closely related to whales.

http://evolution.berkeley.edu/evolibrary/article/evograms_03

lgmayka
12-16-2013, 05:11 PM
British (and probably other countries') scientists are actively creating so-called human-pig hybrids which are genetically 99.9% huma (http://science.howstuffworks.com/life/genetic/human-pig-hybrid1.htm)n:
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In the case of a human-pig hybrid, the egg comes from a pig, and the nucleus comes from a human.

It might seem like this process would produce an embryo that's half human and half pig. In fact, the embryo is almost all human -- scientists estimate that just 0.1 percent of the resulting animal's genetic material is pig DNA.
...
The license for the new research in Britain requires the embryo be destroyed after just two weeks, before it has a chance to develop.
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In other words, a clone-and-kill strategy. The last sentence in the quote is of course an oxymoron--the embryonic human has been developing for two weeks before the researchers kill her/him.

S9 H9
12-17-2013, 12:08 AM
The guy pushing this is hawking books.

Panda's Thumb did a take down of this earlier:

http://pandasthumb.org/archives/2013/12/yes-you-share-a.html?

jeanL
12-17-2013, 12:34 AM
His line of arguments thus far is very, very weak, and if anything shows a lack of understanding of common genetic mutations, which is weird, since he claims to be a Geneticist. He also makes use of a lot of psychological resources to persuade the reader to accept his hypothesis, i.e.




... But, of course, the usual response to any new perspective is "That can't be right, because I don't already believe it." This is the very response that many people had when Darwin first proposed that humans might be descended from apes, an idea that was perceived as ridiculous, or even as subversive and dangerous. And yet, today this exact viewpoint is widely entertained. Its wide acceptance can be attributed primarily to the established fact that humans hold many traits in common with primates. That's what made it convincing. But perhaps Darwin told only half the story. We believe that humans are related to chimpanzees because humans share so many traits with chimpanzees. Is it not rational then also, if pigs have all the traits that distinguish humans from other primates, to suppose that humans are also related to pigs?

But, where he completely lost me was here:




Although I do not concur in Mann's assertion that pigs share more traits with humans than do chimpanzees, I do think pigs and humans share more than enough traits to suggest a relationship. For example, lightly pigmented eyes, in shades of blue, green, and tan, are never found in chimpanzees or orangutans.3 There is, apparently, only one known case of a gorilla with blue eyes.4 Light-colored eyes are also rare in other primates.5 Why, then, are they common in certain human populations? Where did this trait come from? One conceivable explanation is that it was inherited from blue-eyed pigs. Blue is a common eye coloration in swine (as are green, yellow, and tan). The dark pigment (melanin), found so consistently in the irises of nonhuman primates, is beneficial. It absorbs ultraviolet light. To protect their eyes from these damaging rays, pigs depend on their narrowly slit, heavily lashed eyelids. Humans shield their eyes in a similar way, unlike the typical wide-eyed, sparsely lashed ape.

Really!!!! We got blue and green eyes from Pigs?? Where has this guy been for the last couple of years worth of genetic research on aDNA. Denisovans lack the Blue eye mutation on the OCA2 gene, Neanderthals had a different mutation that produce fair skin and red hair, which is not carried by modern humans, blonde hair in Papuans comes from a different mutation than in Europeans. This guy then has the gut to tell the reader than Blue eyes aren't an adaptation but the result of mixing with Pigs, moreover, why on Earth would blue eyes be restricted to Europe, and Asia to a minor extent, if according to him, we come from Chimpazees mixing with Pigs, shouldn't Africans also have Blue eyes then. He seems to forget that just like us, chimpanzee have also been evolving for the last 8-10 million years, Natural Selection would more than account for the differences, and any pseudo-similarity with pigs could just be the result of adaptation to the enviroment. He also uses a very simplistic view of modern humans, and often the characteristics he puts emphasis in are mainly shared by those of European descent, i.e. Nasal Bridge, lots of Cartilages in the Nose, etc. We know that early humans(Erectus/Habilis) had very small if any nasal bridge, and it was likely that their noses resembles more those of modern day Chimps.

lgmayka
12-17-2013, 02:43 AM
Panda's Thumb did a take down of this earlier:

http://pandasthumb.org/archives/2013/12/yes-you-share-a.html?
The problem is that Sayres' "takedown" is just as unconvincing. His most important assertions are unevidenced, and he does not address the most astonishing evidence of all, the observed gene-by-gene fusion of human and porcine DNA (http://www.newscientist.com/article/dn4558-pighuman-chimeras-contain-cell-surprise.html#.Uq-4DfRDtpl).

The unspoken issue in all of this is: If everyone "knows" that humans have no relationship to pigs more recent than 90 million years, why are the vast majority of human hybrid experiments performed with pig DNA rather than chimp DNA? I see two possible explanations:
1) Researchers revere chimps more than humans, so they feel free to experiment with, and kill, embryonic humans but are unwilling to do the same with chimps or any other primates.
2) Researchers suspect that humans have some special relationship to pigs. For example, "The porcine (or pig) heart is most similar to the human heart, and therefore represents the best anatomical fit for replacement." (http://en.wikipedia.org/wiki/Artificial_heart_valve#Tissue_.28biological.29_val ves) Why would a pig heart be more humanlike than a chimp heart? Why is pig skin or intestine used for human grafts (http://www.mayoclinic.org/medicalprofs/xenograft-enterocutaneous-fistulas-ddpue0612.html)?

With so little evidence (either way) of what may have happened in the human evolutionary line millions of years ago, we often fall back on the argument-from-authority. But McCarthy is, apparently, a major authority on hybrids (http://www.amazon.com/Handbook-Avian-Hybrids-Eugene-McCarthy/dp/0195183231), and he has a PhD in genetics as well.

As John Hewitt wrote in his coverage of this hypothesis (http://phys.org/news/2013-07-human-hybrids-closer-theory-evidence.html):
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By and large, those coming out against the theory had surprisingly little science to offer in their sometimes personal attacks against McCarthy.

As any skilled listener might observe, the most important thing in communication is not always hearing what is said, but rather, hearing what isn't said. One thing we have not heard here is objection from those writer-scientists who have any kind of public reputation in the evolutionary sciences. I don't think that is because they didn't hear about the story.
...
As many critics noted, the advancement of scientific knowledge does not require disproving every radical theory that comes along. Lots of incorrect theories exist that cannot, for all practical purposes, be formally disproven. It seems, however, that decent arguments against the hybrid origins theory are surprisingly hard to find, and moreover, the established elders of the field, well, they know it.
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Perhaps both sides can agree that any alleged primate-pig hybrids (like this one (http://www.wqbe.com/programs/the-morning-show/baby-pig-looks-human) and this one (http://www.telegraph.co.uk/news/newstopics/howaboutthat/2469793/Piglet-with-face-of-a-monkey-born-in-China.html)) should be DNA-tested.

GailT
12-17-2013, 03:20 AM
British (and probably other countries') scientists are actively creating so-called human-pig hybrids which are genetically 99.9% human:


I think I remember seeing a documentary about the 'pigman' research in the 1990s. Hopefully this link still works (https://www.youtube.com/watch?v=IG81Bvyzi6w). ;)

GTC
12-17-2013, 03:45 AM
I think I remember seeing a documentary about the 'pigman' research in the 1990s. Hopefully this link still works (https://www.youtube.com/watch?v=IG81Bvyzi6w). ;)


You beat me to it, LOL!

geebee
12-18-2013, 09:16 AM
Well, here's a hypothesized ancestor for us humans (as well as most of our fellow mammals, or at least the placentals): http://www.livescience.com/26936-mother-placental-mammals-infographic.html

Kind of cute, though I don't quite see the resemblance. (Although my eyes are closer to that color than they are to blue.)

I thought blue eyes in H. sapiens, though, were thought to be of very recent vintage -- as in thousands of years, not millions.

"Th-th-th-that's all folks!"

lgmayka
12-18-2013, 10:32 AM
Well, here's a hypothesized ancestor for us humans (as well as most of our fellow mammals, or at least the placentals): http://www.livescience.com/26936-mother-placental-mammals-infographic.html
The full article (http://www.livescience.com/26929-mama-first-ancestor-placental-mammals.html) specifically mentions the revision of dates:
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Their research also suggested placental mammals appeared after the end of the age of dinosaurs [65 million years ago], with the original ancestor developing about 200,000 to 400,000 years after the event.

"This is about 36 million years later than the prediction based on purely genetic data," said researcher Marcelo Weksler at Brazil's National Museum at the Federal University of Rio de Janeiro.

This supports the notion that the mass extinction was a critical event in mammalian evolutionary history. "The diversification of placental mammals was not tied to the breakup of continents from a supercontinent, Gondwana," O'Leary told LiveScience.

The discrepancy between these findings and past research that looked only at genes is the result of the way genetic studies "assign a rate of change to genes through time," O'Leary explained. "A weakness of that approach is that it involves many assumptions about rates of gene change through time."
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I thought blue eyes in H. sapiens, though, were thought to be of very recent vintage -- as in thousands of years, not millions.
Yes, I think you're right. That particular similarity with pigs is apparently an example of parallel evolution (http://en.wikipedia.org/wiki/Parallel_evolution).

tamilgangster
06-27-2014, 08:29 AM
It is possible that there was some retrovirus that infected pig, also infected an ape like ancestor, could also transfer small amounts of DNA which originated from the pig into the apes DNA. This is way more likely than the ape-chimp hybrid theory

dp
12-22-2014, 08:16 PM
It is possible that there was some retrovirus that infected pig, also infected an ape like ancestor, could also transfer small amounts of DNA which originated from the pig into the apes DNA. This is way more likely than the ape-chimp hybrid theory

talk about getting sick from swine flu. :suspicious:
dp :-)

lgmayka
12-22-2014, 10:52 PM
Since you resurrected this thread, I will remind readers that the most shocking well-documented evidence comes from the Mayo Clinic (http://www.fasebj.org/content/early/2004/03/05/fj.03-0962fje.full.pdf):
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In a model of human-pig chimerism, we show that some human hematopoietic stem cells engrafted in pigs contain both human and porcine chromosomal DNA. These hybrid cells divide, express human and porcine proteins, and contribute to porcine nonhematopoietic tissues. In addition, the hybrid cells contain porcine endogenous retroviral DNA sequences and are able to transmit this virus to uninfected human cells in vitro. Thus, spontaneous fusion can occur in vivo between the cells of disparate species and in the absence of disease. The ability of these cell hybrids to acquire and transmit retroviral elements together with their ability to integrate into tissues could explain genetic recombination and generation of novel pathogens.
...
EBV efficiently immortalizes human B cells, but not porcine B cells because they lack the receptor necessary for viral entry, thus enabling selective expansion of human cells (27)...Cell nuclei of the immortalized cells contained only 43 ± 1 total chromosomes, whereas human diploid cells had 46, as expected, and porcine cells had 38, as expected. Chromosome number and banding pattern varied from cell isolate to cell isolate and between the six piglets tested. This finding suggests that the immortalized cells may contain DNA from both species.

To determine whether individual immortalized cells contained DNA from both species, we probed the DNA for a porcine-specific repeat sequence as well as for the human-specific Alu sequence used for the initial cell screening by in situ hybridization. We found that 100% of the immortalized cells were positive for Alu, and nearly 95% of the immortalized cells were positive for the porcine repeat sequence...

The analysis shows intermixture of swine and human chromosomal DNA. The high variation in banding pattern suggests that many distinct fusion events had occurred.
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Approximately 60% of human cells surviving long-term in the pig were cell hybrids. The sustained survival of human hybrid cells over their unfused counterparts suggests that cell fusion may offer a competitive advantage for survival of human cells in the pig. Presumably, the advantage is conferred through the acquisition and expression of essential and/or more compatible genes. For example, a functional α1,3 galactosyltransferase gene was present in all hybrids tested, suggesting that production of Galα1-3Gal might promote survival in the pig.
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ADW_1981
12-23-2014, 02:21 AM
They do, they're called Orcs.

warwick
12-26-2014, 06:06 PM
Phys.org covers the controversial hypothesis that the human race is, to a slight extent, an ape-pig hybrid:

Initial article covering the hypothesis (http://phys.org/news/2013-07-chimp-pig-hybrid-humans.html)
Followup article (http://phys.org/news/2013-07-human-hybrids-closer-theory-evidence.html)

I can't think of any credible evidence from phylogenetics that I have encountered for this hypothesis. When pigs fly I'll give it a second look.

MikeWhalen
12-26-2014, 07:01 PM
maybe the Garden of Eden was in the Ozarks...
:)

M
do you hear banjo's in the background?

VinceT
12-26-2014, 08:59 PM
I have a funny feeling that most females would contest that porcine admixture would be limited to the Y chromosome.