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A chimp-pig hybrid origin for humans?

m.phys.org

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Re: A chimp-pig hybrid origin for humans?

#21

Post by gus_massa »

oinksoft wrote: post #8
bayesianhorse wrote: post #3

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...

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

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.

Re: A chimp-pig hybrid origin for humans?

#23

Post by mr_luc »

a-priori wrote: post #19

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 simi…

Claims, yes. But he doesn't claim it. He puts it forward as a hypothesis.

All useful hypothesis are, by definition, extra-ordinary.

Re: A chimp-pig hybrid origin for humans?

#24

Post by a-priori »

mr_luc wrote: post #23
a-priori wrote: post #19

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 simi…

Claims, yes. But he doesn't claim it. He puts it forward as a hypothesis. All useful hypothesis are, by definition, extra-ordinary.

Of course. It was the phys.org post which invoked Sagan's quote, and I was merely reusing it for rhetorical effect.

Re: A chimp-pig hybrid origin for humans?

#25

Post by callus »

duncan_bayne wrote: post #12
gojomo wrote: post #4

Earlier quoted context omitted.

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.

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.

that would be hilarious indeed.

Re: A chimp-pig hybrid origin for humans?

#26

Post by 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.

Re: A chimp-pig hybrid origin for humans?

#27

Post by mr_luc »

a-priori wrote: post #24
mr_luc wrote: post #23

Earlier quoted context omitted.

Claims, yes. But he doesn't claim it. He puts it forward as a hypothesis. All useful hypothesis are, by definition, extra-ordinary.

Of course. It was the phys.org post which invoked Sagan's quote, and I was merely reusing it for rhetorical effect.

Yeah - but there is a real distinction between theory and hypothesis, which that guy is probably acutely aware of. (Cmd-F on one page of his site shows the word hypothesis used 17 times).

Reading a bit more, it seems like he's got expertise in a corner of science that could be relevant to what the article calls 'morphological change':

"As the increasing apparent, magnificant, speed with which morphological change can occur continues to present itself for us to comprehend, the standard theory of random mutation followed by slow environmental selection, seems to stall. In my own opinion, female choice ... , but other mechanisms of mutation ... , now need to be considered anew. The role of hybridization in driving morphological change, as McCarthy has observed time and time again, particularly in his studies of avian species ... , may be the most powerful mechanism of all."

Okay, so if the "speed of change" problem is a pretty wide-open question without a lot of firm answers, and if this guy has staked out a claim in the problem space ... my reaction is basically "good on ya'!"

Go play god with interspecies breeding and come back in 5 years with an update. :)

Re: A chimp-pig hybrid origin for humans?

#28

Post by ronaldx »

malkia wrote: post #22

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

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 :)

Re: A chimp-pig hybrid origin for humans?

#30

Post by hcarvalhoalves »

a-priori wrote: post #19

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 simi…

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.

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