[Taxacom] teleology example

[Rob Smissen]

"...biased gene-conversion etc" (as suggested by Michael Heads) as well as many more or less random mutational mechanisms might explain how a novel character arises in an individual organism or pedigree, but seems a pretty poor explanation for the fixation of morphological characters in populations and species.

Perhaps the article should have been written more along the lines of  "It is hard to see how these hair like processes would become and remain typical of a variety of snail species if they were not subject to positive selection".

They might of course be a by-product of some other characteristic which is advantageous, but, all other things being equal, being covered with hairs seems likely to come with some disadvantages (he writes while scratching) so selection would favour any snails that managed to decouple the hairs from the hypothetical selected character.

Am I missing or exemplifying John's point?

Cheers
Rob

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