It's quite telling that in this era of abundant genetic data, this guy bases all of his arguments on anatomical similarities and says nothing about genetics. It's all but impossible that a link like what he's suggesting would have been overlooked if pigs had made any significant contribution to the human genome. (Just for example, we've got all sorts of estimates of species divergence dates among primates based on genetic data that should have given nonsensical results if there had been massive influxes of pig DNA in the middle of that history.)
That being said, diluted gene contribution is not the same thing as no gene contribution. To even begin accepting such a theory I would require direct genetic evidence showing considerable horizontal gene transfer between porcine and hominid lines.
I'm not going to say that's impossible, but it sounds like one heck of a stretch. Even just sitting here thinking about it, most genetic inheritance happens one full chromosome at a time. We clearly don't have any full pig chromosomes, so to make this theory work you'd have to have a whole lot of lucky recombination events (chromosomal crossover, etc.) that preserved only the precise genes involved in all these "distinctive pig traits" and got rid of the rest. So what's the selective effect that selects extraordinarily strongly for this random selection of pig-like anatomical traits but against all of the other pig genes that would have usually been linked to them?
In short, this is a very extraordinary claim, and it requires equally extraordinary evidence, especially given how remarkably consistent the known genetic evidence has proven to be.
> most genetic inheritance happens one full chromosome at a time.
is actually not true. Sperm and eggs have only one copy of each chromosome instead of two like most cells in the body. However, that one chromosome is a pretty good mixture of the versions received from each parent due to recombination events that occur randomly during maturation of those cell types. Linkage between nearby genes does exist, but it's not nearly so strong as you seem to imply. Even in a single generation inheritance of two genes on either end of the same chromosome is nearly uncorrelated.
What he is suggesting is that a single hybrid made it's way back into the hominid population. It had children with other hominids, and those children would have had half as much pig DNA. They had children with even less, and so on. After awhile there would be almost nothing left of the pig ancestor. The only genes that would survive such dilution would be ones that were significantly selected for.
I understand the idea of dilution, I just don't understand why he thinks that so many random things would survive it to become defining features of the human species. Remember, he's not just saying that 2% of living humans carry Genghis Khan's Y-chromosome or have red hair or something, he's saying that all of these traits became completely universal.
https://news.ycombinator.com/item?id=7539143
The author posted some replies, one of which points to this article:
http://phenomena.nationalgeographic.com/2013/05/07/charlemag...
That puts it at about 3400 years (the article gets the number from some paper on the topic).
Not exactly 1,000 years, but more like 120-135,000 years for the male line [1], and 200,000 years for the female line [2].
[1] "Sequencing Y Chromosomes Resolves Discrepancy in Time to Common Ancestor of Males Versus Females " dx.doi.org/10.1126/science.1237619
[2] https://www.princeton.edu/~achaney/tmve/wiki100k/docs/Mitoch...
If a generation is about 30 years then you will have close to 33 ancestors lines in your family tree over those 1000 years. That makes 2^33 ancestors or 10 billion, that's impressive (well there is probably a large overlap)
http://phys.org/news/2013-07-human-hybrids-closer-theory-evi...
