
A chimp-pig hybrid origin for humans? - evo_9
http://m.phys.org/news/2013-07-chimp-pig-hybrid-humans.html
======
a-priori
So colour me skeptical. As they say, extraordinary claims require
extraordinary evidence, and this theory is making several extraordinary
claims:

1) A hybridization event indeed occurred in the relatively recent genetic
history of homo sapiens (rather than the unusual anatomic features being
produced some other way).

2) The hybridization was with a close relative of pigs (rather than another
family that has some similar characteristics, or multiple hybridizations that
together gave us the unusual characteristics).

3) The hybridization marks the point at which hominids split from the other
primates (rather than occurring later in one branch of the hominid family
tree).

4) That the genes introduced by hybridization gives hominids their unique
characteristics (rather than being inconsequential).

In return, the theory presents evidence (anatomic oddities and low fertility)
that I would characterize as "interesting" and perhaps "worthy of further
study", but certainly not extraordinary. For this to be plausible, there needs
to be a second avenue of evidence, one not based on anatomic similarities...

That second avenue could be genetic, but they specifically dismiss it,
presupposing a mechanism, backcrossing, that leaves little genetic evidence
that it occurred. Now, I'm no geneticist, but that sounds a bit fishy to me.

~~~
hcarvalhoalves
If you ask a cannibal what's the taste of human flesh, he will say "pork",
which makes this hypothesis funny.

That said, this is way, way too far fetched. Proposing that a primate and a
primitive ungulate can produce an hybrid is already a big stretch, let alone
producing a fertile one. Then, he supports his claim by refusing the genetics,
and hand picks morphology aspects from the suinae that confirm his theory.

What did it for me was the "naked skin" evidence though. It's the human-
selected, domestic pig that is hairless.

~~~
beemoe
re: "naked skin" Did you read where he addresses this question in the first
green box on this page: [http://www.macroevolution.net/hybrid-hypothesis-
section-1.ht...](http://www.macroevolution.net/hybrid-hypothesis-
section-1.html)

Is there some evidence that the hairless trait was the result of human
selection and no hairless varieties existed before human selection?

~~~
hcarvalhoalves
His argument is that the domestic pig and the wild boar are not the same
animal, which is pretty obvious. Then, he claims we don't know where the
domestic pig came from, and that a common ancestor could be hairless.

That is still a pretty weak argument considering from all suinae, the domestic
pig is the only hairless, and for his hypothesis to work, hairlessness would
have to be a dominant trait (otherwise, logic says we should be hairy like a
chimp).

I'm no geneticist or anything like that, but there are some pretty (big) holes
that he doesn't address and attributes to ignorance. You can't make an
hypothesis plausible by claiming about what you do NOT known - you have to
show positive correlation, not absence of negative correlation.

------
tokenadult
Gah. Another crap submission from PhysOrg. This has been going on so long that
many HN participants have called that out as a bad source before. PhysOrg
appears to have been banned as a site to submit from by Reddit (according to
what I've read here on HN). I learned from other participants here on HN that
there are better sites to submit from.

Comments about PhysOrg:

[http://news.ycombinator.com/item?id=3077869](http://news.ycombinator.com/item?id=3077869)

"Yes Physorg definitely has some of the worst articles on the internet."

[http://news.ycombinator.com/item?id=3198249](http://news.ycombinator.com/item?id=3198249)

"Straight from the European Space Agency, cutting out the physorg blogspam:

[http://www.spacetelescope.org/news/heic1116/](http://www.spacetelescope.org/news/heic1116/)
(press release),

[http://www.spacetelescope.org/videos/heic1116a/](http://www.spacetelescope.org/videos/heic1116a/)
(video),

[http://www.spacetelescope.org/static/archives/releases/scien...](http://www.spacetelescope.org/static/archives/releases/science_papers/heic1116.pdf)
(paper).

"PhysOrg: just say no."

[http://news.ycombinator.com/item?id=3611888](http://news.ycombinator.com/item?id=3611888)

"The physorg article summary is wrong, I think."

[http://news.ycombinator.com/item?id=4108857](http://news.ycombinator.com/item?id=4108857)

"Phys.org is vacuous and often flat wrong."

~~~
jhewitt123
I think each submission should be judged on its own merit. HN might do better
to ban crap comments like yours

~~~
specialist
Who's got time for that? There's a reason we consider the source. The Bozo Bit
works.

~~~
jhewitt123
The source was Eugene McCarthy from macroevolution.net. I took the time to
analyze, weigh, summarize, and find a place to publish it. Physorg took it at
face value from me, and published it.

~~~
tokenadult
_Physorg took it at face value from me, and published it._

Well, now I understand why you seem personally offended by the call to weigh
the evidence, which includes weighing the evidence that submissions from
PhysOrg often have the Bozo bit turned on. The previous discussion in this
thread already linked to a much better write-up on the substance of the issue

[http://freethoughtblogs.com/pharyngula/2013/07/02/the-
mfap-h...](http://freethoughtblogs.com/pharyngula/2013/07/02/the-mfap-
hypothesis-for-the-origins-of-homo-sapiens/)

by a developmental biologist who understands and explains why this speculative
hypothesis makes no sense. Read up more about biology before summarizing next
time.

~~~
jhewitt123
I'll let physorg handle themselves on that. I am sure you know more about
their content history here on HN then me. Either way, your "crap submission"
comment was to me so I responded, as you no doubt would yourself to a similar
attack. You will be seeing a lot more science from me on physorg, and
elsewhere, since I just got started
[http://hewitt123.com/blog/?page_id=45](http://hewitt123.com/blog/?page_id=45)
Blocking it hurts your community here a heck of lot more than than me, so
chill out and tune in. Pharngula made a nice composition, did his post start
this thread? If he was honest he would have said what I did, biology and
genetics can't prove or disprove this right now, and that is among the reasons
I raised it for intelligent discussion in the first place. Until we can watch,
and sufficiently understand, chromosomal translocations, pairings, matching,
splittings etc. during meiosis/recombination, criticism from ignorance best
shut up and learn something. Professional scientists calling this guy an
idiot, or pig, or saying, like pharygula, that this guys pants are probably
full of semen, are those that you would be better served in blocking to
improve this forum. Pharygula calls for an experimental cross between a human
and swine, that's not even what was proposed here as an explanation of human
origins.

~~~
jhewitt123
[https://www.youtube.com/watch?v=IIrE9TaC2rc](https://www.youtube.com/watch?v=IIrE9TaC2rc)
Seems Jimmy Kimmel liked it.

------
GuiA
"These days, getting a Ph.D. is probably the last thing you want to do if you
are out to revolutionize the world. If, however, what you propose is an idea,
rather than a technology, it can still be a valuable asset to have."

Man, those newspapers' opening lines are getting worse and worse...

~~~
eli
Phys.org ain't a newspaper.

~~~
GuiA
That's the joke :)

------
Geee
Extremely interesting. I suggest you to read the article at
[http://www.macroevolution.net/human-
origins.html](http://www.macroevolution.net/human-origins.html)

The author seems to be a well-established scientist, and the arguments are
quite plausible, given that this level of hybridization actually could be
possible. What I find amazing (based on the article) is that hybridization
hasn't really been researched very well, and that hybrids aren't actually
infertile, on the contrary to popular belief.

As the article points out, this indeed sounds as ridiculous as Darwin's
proposal that humans descend from apes.

~~~
gus_massa
_Many_ hybrids are infertile. There are some documented cases of fertile
hybrids in very related animals and very related plants (plants are weird!).
[http://en.wikipedia.org/wiki/Hybrid_(biology)#Hybrid_species](http://en.wikipedia.org/wiki/Hybrid_\(biology\)#Hybrid_species)

But and hybrid between a chimp and a pig: simply no way! Even creating a live
pig-chimp hybrid is probably almost impossible, a fertile pig-chimp hybrid
would be a miracle.

~~~
a-priori
It doesn't matter that fertile hybrids are unusual. For evaluating this
theory, it only has to be _possible_ to produce a fertile chimp-pig hybrid.
Then, given a large number of chimp-pig... interactions, you can then assume
that eventually one would be successful.

(That said, before you interpret this as me supporting the theory, please read
my top-level comment)

~~~
sageikosa
The problem is that those pigs and chimps that try to interbreed and fail
would be wasting time and resources and end up falling behind in fecundity to
their "breed true" cousins. Evolution would disfavor such behaviors as they
would represent a vanishingly small percentage of the their respective gene
pools.

~~~
dougk16
Unless, perhaps, both particular species of ape and pig routinely had sex for
pleasure
([https://en.wikipedia.org/wiki/Animal_sexual_behaviour](https://en.wikipedia.org/wiki/Animal_sexual_behaviour)
suggests it's possible), and just happened to cross paths. In this case,
they're not really wasting resources as they would have been having non-
reproductive sex anyway.

~~~
sageikosa
It's not just the "casual" contact time; for females, they would very often be
wasting a reproductive cycle on a fetus that would (in the statistically
significant majority of cases) self-abort.

------
thelibrarian
There's at least one fairly well-know biology professor/blogger who is
unimpressed with what he dubs the "MFAP" hypothesis:

[http://freethoughtblogs.com/pharyngula/2013/07/02/the-
mfap-h...](http://freethoughtblogs.com/pharyngula/2013/07/02/the-mfap-
hypothesis-for-the-origins-of-homo-sapiens/)

~~~
twstws
The thing I find most depressing about these crackpots is that some otherwise
productive scientist has to spend an evening debunking their nonsense. And it
still doesn't stop.

I taught evolution for undergrads, and occasionally had to deal with these
issues from students. It takes time to look into them, and no matter how
thoroughly debunked the theory, some kids find them too irresistible to let go
of. It undermines real education in the end.

~~~
eshvk
> some kids find them too irresistible to let go of. It undermines real
> education in the end.

Teaching is not my cup of tea but isn't an important life lesson teaching kids
how to smell bullshit? If they can do that, surely they will know what books
to pick and what to learn.

~~~
twstws
True, to a point. Debunking one of these in a class is a good exercise.
Preparing a lesson takes time, though, especially when you have to respond to
something out of the blue. You could easily get caught spending all your
limited spare time discussing why these theories aren't science, instead of
the ones that are. Evolution is a big topic, and I'd rather spend my limited
time dealing with the substantive bits.

------
hetman
While the hypothesis itself seems rather unlikely, I think the evidence is
interesting enough that further investigation would certainly yield some
interesting results in their own right.

Major leaps in scientific thinking can often start with some pretty radical
albeit erroneous ideas. But even if not true, these ideas can encourage a
fresh perspective and a new approach for teasing apart the observable world.

~~~
thotpoizn
This. It seems pointless to me to proceed with so much hand wringing and "my
science-peen is bigger than yours" posturing, when we have ample opportunities
(and plenty of pigs and bonobos) to test the hypothesis via experiment. Isn't
that sort of the next step in a fairly tried-and-true method many here are
usually quite fond of?

Personally I think the odds of any meaningful success are extremely low, but
the cost to explore and experiment are also quite low. I'd rather trust "we
attempted insemination of {x} bonobos with {y} varieties of pig sperm, but
failed to achieve impregnation" (... or succeeded, or whatever) - over "I'm
really smart, and trust me - this couldn't possibly work."

------
ronaldx
This is highly unlikely origin story. The main problem is that genetic data
strongly and consistently suggests we are further from pigs than chimpanzees
are.

Genetic material often finds ways of crossing species boundaries: in lower
organisms, horizontal gene transfer is commonplace. But, this is just not
supported by any scientific evidence.

~~~
hetman
I believe he addresses that by suggesting backcrossing with the chimp line.
Still seems extraordinary such a cross should originally be even remotely
viable.

------
duncan_bayne
My gut feel is that this is bat-shit crazy, but wouldn't it be amusing to see
the response from the Jewish and Islamic world should it turn out that humans
are pig hybrids? ;)

~~~
gojomo
Vindication?

The broad (though not universal) taboo against eating primate meat has some
basis in the higher risk of shared/cross-species diseases, due to a closer
genetic relationship.

If there's a little pig in us, that'd argue for stronger taboos against eating
pork... exactly as in Judaism and Islam.

~~~
duncan_bayne
Yes - I think many religious taboos have their basis in sensible food hygiene
and incest avoidance. But that's not how it's pitched; often the claim is that
"pigs are unclean".

Which is why it'd be funny.

~~~
klipt
Dead human bodies are considered unclean too. That's not a value judgment
about live humans.

------
gojomo
Can chimp-pig hybridization be reproduced in a labratory? (Would it be ethical
to attempt?)

~~~
iuguy
I believe a Dr Krieger tried several times with mixed success.

Poor pigley.

------
jvm
Hybridization is actually a pretty interesting hypothesis for species
differentiation in higher vertebrates, given that generations are often very
long, hindering traditional accounts of evolution-through-mutation.

~~~
sageikosa
Recombination occurs very time a new sex cell is produced during the crossing
over event, Dawkins dispels the random mutation as the only means of genetic
shift very early in his book "The Selfish Gene" as the crossing over process
can split chromosomes mid-gene for longer, more complex DNA sequences.

------
nealabq
Jean Auel's _The Clan of the Cave Bear_ book-series explores the possibilities
of Neanderthal/Cro-Magnon interaction, but this article brings up a whole new
set of intriguing plot twists.

~~~
a_bonobo
So far, there are two proven gene-flow events to Homo sapiens from non-
sapiens: Homo neanderthalensis and from the Denisova hominin population. In
the latter case science isn't sure yet whether the Denisova hominin was a sub-
species or species.

[http://en.wikipedia.org/wiki/Archaic_human_admixture_with_mo...](http://en.wikipedia.org/wiki/Archaic_human_admixture_with_modern_Homo_sapiens)

We probably got some immunity-related genes from neanderthals, but probably
not red hair - red hair in neanderthals is caused by a different mutation that
doesn't exist in humans.

------
bayesianhorse
You can't make this stuff up. Or can you? At first I thought it's an elaborate
joke, but I couldn't find any real pointers to the jocular nature...

~~~
oinksoft
This is quite real. McCarthy has been published by Oxford Press. Here it is
from the horse's mouth: [http://www.macroevolution.net/human-
origins.html](http://www.macroevolution.net/human-origins.html)

~~~
gus_massa
Do we have a designed ornithologist here to comment about the book?

My guess is that all the cases in the book are hybrids between very related
bird species. For example, in the PowerPoint presentation, there is a hybrid
between two types of crows, other cases are not so obvious, but IANAO. But I
didn't see any hybrid between two obvious distant species, for example between
an ostrich and a stork.

------
malkia
What's the different between hybrids and breeds (as in dogs for example)?

~~~
ronaldx
A simple way to define a 'species' is any group of creatures that can produce
viable, fertile offspring.

So dogs are breeds - they're part of the same species - because if you mate a
great dane with a chihuahua, you'll get a fertile dog (I believe; if you plan
to experiment, I recommend the chihuahua is male and great dane is female). If
you're lucky, that dog will have desirable characteristics that may one day
end up being the parent of a new breed.

But horses and donkeys are not breeds - they're different species - because if
you mate them you get a mule which is not fertile (a hybrid, therefore).

In the end, this definition is a bit too simplistic because it's not
necessarily always so clear-cut. Hence the article here :)

~~~
nitrogen
I would expect that a "breed" should also be stable. That is, pairings between
male and female members of the same breed should produce offspring of that
same breed nearly every time.

[https://en.wikipedia.org/wiki/Breed](https://en.wikipedia.org/wiki/Breed)

------
c3d
Interestingly, this very same hypothesis was the basis for a novel by french
author Bernard Werber called "le père de nos pères" (the father of our
fathers), published in 1998.

~~~
c3d
Wikipedia article
[http://fr.wikipedia.org/wiki/Le_Père_de_nos_pères](http://fr.wikipedia.org/wiki/Le_Père_de_nos_pères)

------
webwielder
Paging Mr. Betteridge, Mr. Betteridge to the white courtesy phone.

------
dsjoerg
Men are pigs!

------
floobynewb
I actually find this plausible. Like the author I also have problems believing
that random mutation and selection is a complete/adequate explanation. Just a
hunch, there's a deeper theory to be had here.

------
johnmw
<low brow comment> So Mrs. Garrison was right all along?
[http://www.youtube.com/watch?v=CRBHxJBUv_A](http://www.youtube.com/watch?v=CRBHxJBUv_A)
</low brow comment>

