Re: Resetting the "molecular clock hypothesis"

[David Marjanovic <david.marjanovic@gmx.at>]

> Riv Biol. 2008 Jan-Apr;101(1):93-108.

Rivista di Biologia is a journal without peer-review that publishes 
creationist attempts to imitate the scientific process. It can be safely 
ignored on that basis alone.

> There exists a remarkable correlation between genetic distance as measured 
> by protein or DNA dissimilarity and time of species divergence as inferred 
> from fossil records. This observation has provoked the molecular clock 
> hypothesis. However, data inconsistent with the hypothesis have steadily 
> accumulated in recent years from studies of extant organisms.

As usual, creationists are -- at best -- behind their times in their 
understanding of scientific knowledge. Even the ornithologists now 
understand that the molecular clock hypothesis holds only as a very, very 
crude approximation, that each clade, each gene, and lastly each base pair 
has its own speed of evolution.

> Here the published DNA and protein sequences from ancient fossil specimens 
> were examined to see if they would support the molecular clock hypothesis. 
> The hypothesis predicts that ancient specimens cannot be genetically more 
> distant to an outgroup than extant sister species are.

A very strict form of the molecular clock hypothesis would predict that. But 
why bother? We already know it is wrong. If I had been a reviewer on this 
manuscript, I'd have recommended rejection on the grounds that the author 
doesn't know what they're talking about. But, as mentioned, nobody was a 
reviewer.

> Also, two distinct ancient specimens cannot be genetically more distant 
> than their extant sister species are.

Does that mean anything?

> The findings here do not conform to these predictions. Neanderthals are 
> more distant to chimpanzees and gorillas than modern humans are. Dinosaurs 
> are more distant to frogs than extant birds are. Mastodons are more 
> distant to opossums than other placental mammals are.

More distant to opossums than _any other_ placental mammals are? Was the 
damage to the sequence counted as difference, or what?

> The genetic distance between dinosaurs and mastodons is greater than that 
> between extant birds and mammals. Therefore, while the molecular clock 
> hypothesis is consistent with some data from extant organisms, it has yet 
> to find support from ancient fossils.

Which extant birds and which mammals?

And what is this talk about distance anyway? Why not count apomorphies 
instead of differences? Oh, right, that's because...

> Far more damaging to the hypothesis than data from extant organisms, which 
> merely question the constancy of mutation rate, the study of ancient 
> fossil organisms here challenges for the first time the fundamental 
> premise of modern evolution theory that genetic distances had always 
> increased with time in the past history of life on Earth.

Told you the author is a creationist: "Being ignorant, I believe that some 
unrealistic hypothesis is a fundamental premise of modern evolution theory, 
without which the theory would utterly collapse; this hypothesis is wrong 
(especially if my lack of understanding of the data is counted as evidence); 
therefore the theory of evolution is wrong; therefore the lack-of-theory of 
creationism is right; therefore Jesus. Praise the Lord!!!1!" (If you're 
bored, count the errors in the logic.)

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Any discussion of this should be kept offlist, in order to avoid useless 
discussions of creationism (as required by 
http://www.lifesci.ucsb.edu/~mrowe/dinosaur/administrivia.php#no_nos). 
Please don't time me out just yet -- I'll be away from any computer from 
July 27th to August 9th anyway.