lpetrich

URL: <a href="http://molbiolevol.org" target="_blank">http://molbiolevol.org</a> -- a technical journal. One can purchase articles from that site, but I contented myself with reading the abstracts.

The September 2002 issue has an article by Chang et al. on reconstructing an early version of a visual pigment with molecular-evolution techniques. This pigment had belonged to ancestral archosaurs (crocodilians, dinosaurs, birds) that lived about 240 million years ago. They placed a reconstructed version of the gene for this protein into a mammalian cell line, which proceeded to express it. The authors of that paper found that this protein was capable of functioning as a visual pigment, though its sensitivity peak was a bit redder than those of the modern proteins used to reconstruct it.

Although not quite Jurassic Park, it is an interesting test of molecular-evolution theorizing.

That issue also has an article by Escriva et al. about analyzing lamprey and hagfish genes to see how they fit into the "2R" hypothesis of vertebrate genome evolution, that there had been two genome doublings early in vertebrate history. They find that lampreys and hagfish split off after the first genome duplication, but before the second one in the lineage leading to the jawed vertebrates (gnathostomes).

However, this double doubling has been somewhat obscured by additional gene doublings, gene loss, etc., as the authors note.

The May 2002 issue has an article by Gaunt and Miles on the early evolution of insects. They worked out a consistent molecular clock with the help of gene sequences from cockroaches, orthopterans (grasshoppers, locusts, crickets), hemipteran bugs, dipterans (flies, mosquitoes), and lepidopterans (butterflies, moths), and successfully calibrated it with early fossils of cockroaches. They also conclude that insects and fairy shrimps (Anostraca) had diverged about 420-430 million years ago.

Other studies had revealed that insects are closest to crustaceans among the other arthropods; now we are finding out which ones the insects are closest to.

[ September 09, 2002: Message edited by: lpetrich ]</p>

Automaton

Most articles on Molecular Biology and Evolution are free. Wait a while, and the new ones should eventually become downloadable.

Skydancer

Doubly interesting. The physical characteristics described are what one would expect from evolution. Since the sun itself (like all main-sequence stars) gets brighter, and therefore blue-shifts its light output over time, an ancient light-sensitive protein would be expected to be adapted to somewhat redder light than we have now.