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Showing posts from January, 2008

Functional adaptations: ontogeny and evolution

As I study functional morphology for my thesis, I think about this subject an unusual (or unhealthy) amount. And there's one thing that's been hurting my head for the last few days.

That is: how does physical stress as a response to function, e.g. biting reaction force and its skeletal response, work as selective pressure on morphology? In other words, what are the mechanisms behind functional adaptation as seen by morphological change through time?

Skeletal response to mechanical stresses occur during the lifetime of an individual. These are ontogenetic developments that are not the same as primary ontogenetic development, as shared by all members of the species (predestined by the genome), but secondary responses brought about by extrinsic factors. So surely, any changes acquired as a direct response to extrinsic mechanical stresses, must be acquired traits, thus aren't passed down to the next generation.

My question therefore is, how do these acquired traits get passed dow…

When pigs ruled the Earth

My good friend and colleague at the University of Bristol, Sarda Sahney and our supervisor Mike Benton recently published a paper on the extinction and recovery of terrestrial ecosystems at the Permo-Triass boundary.

Here's her blog about it:
Fish Feet

Here's the University of Bristol news on it:
http://www.bristol.ac.uk/news/2008/5785.html

And here's the actual paper at the Royal Society:
http://journals.royalsociety.org/content/qq5un1810k7605h5/

The PT extinction is often called the 'mother of all extinctions' and wiped out some 90% of life on Earth. The junior author of this paper (though hardly the junior) Mike Benton wrote a book about the whole thing a few years back titled 'When Life Nearly Died'. About a third of his book's about the history of the PT extinction studies, another third about his excursions in Russia and the rest is the extinction event itself - well, maybe this is a bit overexaggerated and maybe had a bit more on the extinction event th…