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Yes, you share a common ancestor with pigs, but it was a long, long time ago.

Posted 16 December 2013 by M. Wilson Sayres

I was recently invited to comment on an Anthropology Network discussion on LinkedIn, where someone asked, "I'm wondering what this community's thoughts are about the theory that humans are a hybrid?" and linked to the blog post by Eugene McCarthy supposing that humans resulted from a hybridization event between chimpanzees and pigs. Because it is a private network, I'd like to repost, with some expansions, what I added to that discussion. But, let's just start off by clearing the air: 

 Chimpanzees did not mate with pigs and produce humans.

Chimpanzee, by Ikiwaner (Own work), via Wikimedia Commons
Adorable piggy, by A R, via Wikimedia Commons

I am not a little piggy!

I was surprised that a group of anthropologists would even consider this a reasonable topic for discussion, but perhaps this speaks to the need for more cross-discipline communication. 

 I find it distressing that the chimp-pig hybrid article dismisses the abundance of genetic evidence that provides no support for such a hypothesis of human ancestry. There are several scientific and logical flaws with the supposition that humans resulted from what must have been multiple matings between chimpanzees and humans. Also, please see an alternative discussion of this hypothesis by PZ Myers here, then another summary and discussion by ARTIOFAB here. 

1. Humans are genetically very similar to chimpanzees, and genetically distant from pigs
There are no regions of our genome where the genomic content more closely resembles a pig than a chimpanzee. If such a hybridization had occurred, we would, like we do with the Neandertal and Denisovan genomes, find regions where segments of modern humans are more closely related to pigs than any other species, but we do not. 

 I really don't understand how anyone can look through images of pigs and think that we resemble pigs more than we do chimpanzees or bonobos:

Pan paniscus (bonobo) By Pierre Fidenci (http://calphotos.berkeley.edu), via Wikimedia Commons

2. Body hair has been lost independently in many mammalian lineages.
Yes, hairlessness over most of our bodies evolved in humans, but it did so independently in the human lineage. Similarly hairlessness independently (we call it convergent evolution) evolved in naked mole rats, manatees, and cetaceans (dolphins and whales). Rodents are actually more closely related, evolutionarily, to humans than pigs, but we don't see a naked mole rat - chimp hybrid theory because it is obviously ridiculous to the general public. The chimp-pig hypothesis is even more improbable. And, furthermore, many pigs have not lost hair on their bodies or faces.
Bearded Pig, by Art G. from Willow Grove, PA, via Wikimedia Commons

3. Chromosomal and genetic differences between chimpanzees and pigs preclude fertile hybrids.
The chromosomal differences between chimpanzees (48) and pigs (38) would preclude any chimp-pig zygote from developing, or even replicating properly. The author greatly over-exaggerates claims about the fertility of hybrids of sheep-goat hybrids (most are stillborn), and also misuses the term geep (which refers to a chimera of sheep/goat cells). The author also ignores the close evolutionary relationship of sheep and goats, where the chromosomes (and the breaks/fusions) can readily be mapped, where most of the gene content is still conserved among chromosomal regions. Such an identity of the order and orientation of gene content does not exist between chimpanzees and pigs, but is possible between the very closely related human and chimpanzee (all chromosomes are one-to-one, except for human chromosome 2, which is a fusion of two ancestral chromosomes that remained unfused in chimpanzee). 
Mapping of human and chimpanzee chromosomes, by JWSchmidt, from Wikimedia Commons
4. Fossil evidence can account for all of humans ancestry to the human-chimp common ancestor.
At what point in time would this have occurred? Certainly not the present. We have fossil evidence of modern humans, ancient humans, ancient hominids, ancient apes, ancient monkeys, and so on. Science can account for the progression of humans from our shared ancestor with chimpanzees, and even further back. At no point in history do the fossils of ancient humans in any way resemble the fossils of ancient pigs. 

 5. Modern species share common ancestors, they did not beget each other.  
Modern humans did not evolve from modern chimpanzees any more than modern chimpanzees evolved from modern humans (that is, not at all). Fossil evidence suggests that the chimp-human common ancestor looked a lot more like a modern chimpanzee than it did a modern human, suggesting many more physical changes along the human lineage, but the modern chimpanzee has also experienced changes since our most recent common ancestor together, approximately 6 million years ago. Both humans and chimpanzees share a common ancestor with pigs about 90 million years ago.

6. Domesticated pigs and chimpanzees do not live in the same locations. 
Pigs (with reduced body hair) were domesticated in East Asia and in Europe. Chimpanzees live in central Africa. They live on different continents. They did not ever have the opportunity to get busy. Wild boars can be found in northern Africa, but this is still quite far from where chimpanzees live, and if they do overlap in range, it is only a very recent occurrence.

Wild Boar, by Volker.G (Own work), via Wikimedia Commons
7. Why hasn't an experiment been done? 
You could attempt each of the possible combinations (chimp sperm with pig eggs, and pig sperm with chimp eggs) and test the viability. It it works, we can have this discussion. If not, this guy needs to stop spouting nonsense that detracts from the real science being done.
By David.Monniaux, via Wikimedia Commons

27 Comments

DS · 16 December 2013

The thing about forming hypotheses is that they have to explain the available evidence. Ignoring all of the evidence and forming hypotheses contrary to the evidence is a waste of time. That's why you have to know what others have discovered before you can make any contributions yourself. Reinventing the chromosome isn't going to be any more constructive than reinventing the wheel, especially if you think that a square wheel is somehow the way to go.

https://me.yahoo.com/a/JxVN0eQFqtmgoY7wC1cZM44ET_iAanxHQmLgYgX_Zhn8#57cad · 16 December 2013

About as good as "ancient alien theorists" claiming that we're alien-ape hybrids.

Or ID.

Plus, why are there still pigs, then?

Glen Davidson

John Stell · 16 December 2013

This comment has been moved to The Bathroom Wall.

TomS · 16 December 2013

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j. biggs · 16 December 2013

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https://me.yahoo.com/a/JxVN0eQFqtmgoY7wC1cZM44ET_iAanxHQmLgYgX_Zhn8#57cad · 16 December 2013

This comment has been moved to The Bathroom Wall.

TomS · 16 December 2013

https://me.yahoo.com/a/JxVN0eQFqtmgoY7wC1cZM44ET_iAanxHQmLgYgX_Zhn8#57cad said: Perhaps you have an explanation. Not, magic man said so. Evidence. We're waiting. Glen Davidson
But there is no explanation which does not involve common descent with modification. So it is rather pointless to ask for evidence. The closest that the evolution-deniers get to an "explanation" is that maybe some agency which is up to the task of doing anything at all might have decided to do things this way, rather than any of the infinite other possibilities open to them. Who, what, when, where, why or how? Don't ask. The evolution-deniers have discovered that whenever they make some small steps on the path to an explanation, it turns out to be an embarrassment. So they have decided that the best policy is silence. Why is the human body most similar to that of chimps and other apes? It could be that the intelligent designers responsible for that wanted humans to behave like apes. It could be that the intelligent designers responsible for that were constrained by the raw material that they were given to work with. Or it could be that that extremely complex pattern of relationships is just a matter of chance, and needs no explanation. If you don't want to accept scientific investigation of the world of life, those seem to be your choices.

Henry J · 16 December 2013

What would Miss Piggy see in a chimpanzee, anyway? She prefers frog.

M. Wilson Sayres · 16 December 2013

Henry J said: What would Miss Piggy see in a chimpanzee, anyway? She prefers frog.
Why didn't I think of that argument?!

Joe Felsenstein · 16 December 2013

Has McCarthy found even one gene for which humans are closer to pigs than to other (nonchimp) primates?

I gather that he cannot cite even one such. A major prediction of a hybridization event is that there should be genetic material from both parents in the hybrid. If McCarthy cannot cite any DNA sequence evidence in his favor, then his hypothesis richly deserves to be ignored.

Sequence data that can be examined for this is available in a number of places on the Internet. For example at the OrthoMam site (here) there are trees constructed from aligned DNA sequence data for 13,404 coding sequences. The species include human, chimp, a number of other primates, and pig. Can McCarthy find even one of them for which humans are located within the artiodactyls?

I looked at 16 trees for loci on chromosome 8 in that resource. In the great majority Homo was sister to Pan, and in the rest Homo wandered a bit further away, but always stayed in the apes. In no case did a locus put Homo anywhere near Sus, the pig.

hrich · 16 December 2013

Wouldn't an attempt to propagate from mules, whether by mating with horses, donkeys or other mules, be a more fruitful field for study by serious hybridization experts?

M. Wilson Sayres · 16 December 2013

Joe Felsenstein said: Has McCarthy found even one gene for which humans are closer to pigs than to other (nonchimp) primates?
As far as I can tell, he has not analyzed any genetic data. In all of the comparative work I've done, I've never come across a genomic region in humans that more closely resembled artiodactyls than primates.

M. Wilson Sayres · 16 December 2013

hrich said: Wouldn't an attempt to propagate from mules, whether by mating with horses, donkeys or other mules, be a more fruitful field for study by serious hybridization experts?
Yes, I think analysis of mules would be more fruitful for "serious hybridization experts", and people have been studying this. For example, a paper in 2013 by Xu et al (Andy Clark's lab), studies variation in genomic imprinting using horse-donkey hybrids: http://www.pnas.org/content/110/26/10705.long

Matt Young · 16 December 2013

I was surprised that a group of anthropologists would even consider this a reasonable topic for discussion, but perhaps this speaks to the need for more cross-discipline communication.

You are far too kind.

M. Wilson Sayres · 16 December 2013

Matt Young said:

I was surprised that a group of anthropologists would even consider this a reasonable topic for discussion, but perhaps this speaks to the need for more cross-discipline communication.

You are far too kind.
It turns out that I was a little misled. While there are many trained scientists in the Anthropology Network, and it is a private group (meaning you have to --I have no idea-- to get in), they will allow anyone to join who has an interest in anthropology. Still, that no one chimed in to say this was an absurd idea astounds me. Furthermore, after my comments, several people have chimed in about how genetics cannot be used in this case, because… ?

Robert Byers · 16 December 2013

AS a YEC there are a heap of hybrid observations one could make on this subject.
Creationists want to add our voice also that humans are not part pigs. We are glad this forum has taken this stand also.
it is not because we deny science or hard working scientists insights and research! We interpretate the evidence differently.
So much could be said and I guess can't.
Save one thing.
Is there biological scientific evidence for us being related to apes anymore then to pigs??
or is it just WE LOOK LIKE THEM!
After all we would look like them if a creator had to give us the best body type on earth for our lives and we couldn't have one that was unique to ourselves because of our uniqueness in our creation.
I mean we are the only creatures who are renting another creatures bodyform because we must be in the blueprint of nature.
the hunch of looks is not scientific evidence but would be also a hunch for a special creation.
A line of reasoning. No worse then a lot of them.

By the way we first were hairless and then got a little hairy but it was not really needed. The body was over sensitive back in the day.

KlausH · 17 December 2013

Didn't we see something very similar in South Park?
http://www.imdb.com/title/tt0890648/quotes

Ron Okimoto · 17 December 2013

Joe Felsenstein said: Has McCarthy found even one gene for which humans are closer to pigs than to other (nonchimp) primates? I gather that he cannot cite even one such. A major prediction of a hybridization event is that there should be genetic material from both parents in the hybrid. If McCarthy cannot cite any DNA sequence evidence in his favor, then his hypothesis richly deserves to be ignored. Sequence data that can be examined for this is available in a number of places on the Internet. For example at the OrthoMam site (here) there are trees constructed from aligned DNA sequence data for 13,404 coding sequences. The species include human, chimp, a number of other primates, and pig. Can McCarthy find even one of them for which humans are located within the artiodactyls? I looked at 16 trees for loci on chromosome 8 in that resource. In the great majority Homo was sister to Pan, and in the rest Homo wandered a bit further away, but always stayed in the apes. In no case did a locus put Homo anywhere near Sus, the pig.
You can find the gene where Gish found his bullfrog gene that was closer to humans than it was to a chimp. It is too bad that you can't ask Gish where that is. http://cre-ev.dwise1.net/bullfrog.html

Ron Okimoto · 17 December 2013

M. Wilson Sayres said:
Joe Felsenstein said: Has McCarthy found even one gene for which humans are closer to pigs than to other (nonchimp) primates?
You probably will not find such genes that differentiate chimps and humans, but highly conserved protein genes like histone genes where you might have 1 or 2 amino acid substitutions between mammals and plants you might find that humans are closer to a cabbage than they are to a tapeworm or some mollusc that might have a couple different amino acid substitutions. As far as I can tell, he has not analyzed any genetic data. In all of the comparative work I've done, I've never come across a genomic region in humans that more closely resembled artiodactyls than primates.

harold · 17 December 2013

Matt Young said:

I was surprised that a group of anthropologists would even consider this a reasonable topic for discussion, but perhaps this speaks to the need for more cross-discipline communication.

You are far too kind.
I wonder if the Dunning-Kruger effect has always been as strong and prevalent as it is now, or if the post-modern environment, in which everyone is surrounded by and dependent on technology that they more or less literally cannot fully understand, is provoking a "Dunning-Kruger crisis", in which a disastrously high proportion of the population thinks that they are expert in things that they are completely ignorant of. In medieval times, the word "mystery" referred to a skilled handicraft that required extensive training to master. People understood the surrounding technology well enough to understand that they weren't expert from birth in everything. The nineteenth century was full of ideas that seem hilarious and crackpot to us, but they were speculating about areas that were unknown at the time. Today, it just seems that for any well established body of scientific (or historical etc) fact, there are a bunch of self-congratulating, posturing, strutting buffoons who simultaneously are ignorant of the basics, yet deny the facts, and they seem to attract hoards of admirers.

daoudmbo · 17 December 2013

Wow, I read through some of Eugene McCarthy's blog post where he claims many times to be a geneticist. What a crackerjack! I'm always in awe of internet cranks, do they realize they are cranks? I would like to meet them in person, maybe not directly interact with them, but observe them, how does a crank brain actually work? Especially if they're actually sincere with no trace of humour.

Matt Young · 17 December 2013

... there are a bunch of self-congratulating, posturing, strutting buffoons who simultaneously are ignorant of the basics, yet deny the facts, and they seem to attract hoards of admirers.

Oh, come on, Harold, why don't you stop pussyfooting and say what you really mean?

nobodythatmatters · 17 December 2013

Robert Byers said: AS a YEC there are a heap of hybrid observations one could make on this subject.
if you've hybridized your observations, is it still a heap, or is it now half of a heap?
Creationists want to add our voice also that humans are not part pigs. We are glad this forum has taken this stand also.
don't forget that to get credit for a right answer, you must also show your work. How you got the answer is the difference between understanding the subject and just guessing correctly.
it is not because we deny science or hard working scientists insights and research! We interpretate the evidence differently.
scientists interpret evidence, you interpretate it...so i guess that is different. also, isn't it effectively the same as denying the research of hard working scientists when you choose to ignore that work when interpretating the evidence?
So much could be said and I guess can't.
is it because you lack the necessary english skills? because i'm pretty sure you can say whatever you want, otherwise.
Save one thing. Is there biological scientific evidence for us being related to apes anymore then to pigs??
yes (assuming you meant "than"). (if you actually meant "then", the answer is no. there is no evidence we were related to apes and then, sometime later, were related to pigs)
After all we would look like them if a creator had to give us the best body type on earth for our lives and we couldn't have one that was unique to ourselves because of our uniqueness in our creation. I mean we are the only creatures who are renting another creatures bodyform because we must be in the blueprint of nature.
if this is the best body type the creator could come up with, he's an idiot. the part about we couldn't have a unique body type because of our uniqueness makes no sense at all. what are you trying to say there, because i cannot find an idiot filter that parses that into something coherent.
A line of reasoning. No worse then a lot of them.
this is actually true. there are lots of mind-bogglingly stupid lines of reasoning out there and your mind-bogglingly stupid line of reasoning is no worse than those. It would be nice if you showed a little ambition and aimed a little higher though. How about trying for "kinda stupid" or "a little silly" instead?
By the way we first were hairless and then got a little hairy but it was not really needed. The body was over sensitive back in the day.
and you base that on absolutely nothing. and yes, i shouldn't feed the trolls and won't be replying to him again in this thread.

j. biggs · 17 December 2013

8. The specificity of human/ape spermatazoa most likely prevents egg fertilization in non-hominids.

Bedford JM, Sperm/egg interaction: the specificity of human spermatozoa. Anat Rec. 1977 Aug;188(4):477-87.

YaFen Shen · 17 December 2013

I much prefer that folks under-exagerate.

Frank J · 17 December 2013

The closest that the evolution-deniers get to an "explanation" is that maybe some agency which is up to the task of doing anything at all might have decided to do things this way, rather than any of the infinite other possibilities open to them. Who, what, when, where, why or how? Don't ask.

— TomS
If any evolution-deniers had the slightest confidence that the evidence supported any of the mutually-contradictory literal interpretations of Genesis - including the young-earth ones that even most evolution-deniers find absurd - they'd be so busy volunteering all the whats, whens, wheres, and hows, and having spirited debates among themselves, that they'd have no need to obsess over a designer (which evolution does not rule out anyway) or over their "Darwinism" caricature. Instead, anti-evolution activists have been steadily retreating from anything testable about their own "theory." The few exceptions are those like Behe, who flat-out concedes ~4 billion years of common descent (albeit with possible in-vivo tinkering by "someone, somewhere, somehow at some time"). And even their objections to "Darwinism" are increasingly about how acceptance is the root of all evil, rather than any "weakness" in evidence.

Ray Martinez · 30 December 2013

M. Wilson Sayres has posted three pictures in her common ancestry topic. The first picture is that of a chimpanzee, and the third picture is that of a caucasian or light skinned baby.

Since human evolution began in Africa would it not be more accurate to have posted a picture of an African or dark skinned baby?