Tomk80 said:I think it's actually an interesting question how far apart species producing hybrids are genetically. Then I don't mean karyotyping, as that is relatively unimportant, but more genetic distance, for example determined by differences in homologuous genes or proteins. But I could imagine that this is not the whole story.
Yeah, it's complex. My field is canine genetics. One example from my current work is how certain combinations of breeds form unfit offspring.
From today's TimesOnline: 'Crossing a pug and a pekinese has produced an animal with such a distorted face that its eyes kept popping out'.
I read about some work done creating crosses between very small and large breeds. Some of the resulting crosses ended up with a set of extra long front legs or back. Obviously not darwinian ideals of fitness for thier environment.
As I understand it, a likely theory is that we as a species being so successful killed off our closest relatives through expansion, competition and hybridisation.
On the subject of genetic closeness, this is from an article at the BBC entitled 'Chimps genetically close to humans':
bbc said:According to this analysis, chimpanzees and humans occupy sister branches on a family tree, with 99.4% genetic similarity. Next on the tree are gorillas, then orang-utans, followed by Old World monkeys.
None of the primates were closely related to mice, which were used as a control.
Dr Wildman said: "You could say that humans and chimps are as similar to one another as say horses and donkeys.
"And there really isn't much evidence for them to be divergent at the family level, which would be something like the divergence between apes and monkeys.
"There has been this notion since Aristotle's time of this great chain of being with humans at the top and then less complex life at the bottom. But while that might seem intuitive to some people, it doesn't appear to be borne out by the data.
"There's been as much change on the lineage on the line leading to chimpanzees as there has been on the lineage to humans since they last shared a common ancestor around six million years ago."
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