Of interest to the 'non-random' types...

Hi Judge,

quote:

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Judge:
Perhaps as the notorious PB (yikes...hi PB ) seemed to say some mutations are much more "non random".
Thus the ones shared by chimps and humans would have occurred due to a "mechanism".

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How could we weigh up whether this was a possibilty with regard to a particular mutation shared by chimps and humans?
How can we say that with regard to a particular shared mutation this is highly unlikely?

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..ouch PB ...actually, no he got banned so he won't be responding to me, attacking you, reiterating the same things over and over again..that's what salty's function is on the board Regarding your question about a particular shared mutations, one would not compare chimp to human without having what is known as an outgroup. Without context, just comparing two sequences is not very informative wrt shared ancestry. Also, not much weight is put on a single shared mutation but usually a regions with a lot of mutable sites are compared since it ultimately rests on statistical support. In any case, if one looks at say orang, gorillas, chimps, and humans at a particular sequence (say mtDNA region of your choice) one would see that more of the sequence is identical between human and chimp than chimp and gorilla or human gorilla. Chimps, humans, and gorillas share more sites in common than any with orang..and so on. We know from genetics and the discovery of DNA as material for passing on heritable traits that mutations are passed on from parent to offspring. We know that mutations in bacteria, fruit flies, etc. work under similar constraints and mechanisms as in primates...thus the parsimonious explanation for shared mutation is shared ancestry. One would have to postulate a mechanism operating to produce mutations that mimic common ancestry that has been recreated for every single species on the planet...this hypothesis would face the counter evidence of everything known about transmission genetics (including studies of human diseases), population genetics, and mutation research including the huge amount of research that has gone into developing polymerases for biological work like Taq polymerase used in PCR which can also produce errors.I am oversimplifying everything here but hopefully the point is clear.cheers,
M