Friday, August 21, 2009

Headline miscellany

I'm still on my quest to catch-up from my lazy summer, so here are a few interesting headlines for Friday:

A recent paper in Evolution by Lynch and Wagner looked at oviparity and phylogeny in sand boas, Did Egg-Laying Boas Break Dollo's Law? Phylogenetic Evidence for Reversal to Oviparity in Sand Boas (Eryx: Boidae). From the abstract:

We reconstruct ancestral parity mode on this phylogeny and present statistical evidence that oviparity re-evolved in a species of Old World sand boa in the genus Eryx nearly 60 million year after the initial boid transition to viviparity. Remarkably, like other viviparous boas hatchlings of oviparous Eryx lack an egg-tooth providing independent evidence that oviparity is a derived state in these species.

That is indeed remarkable. Or is it mediated design? I don't know, but it's probably worth looking into.

Today's Science has a report about dog legs. Remember my ongoing argument that mendelian genetics is not enough to explain post-Flood species diversity? The research by Parker et al. demonstrate that it's not even enough to explain intraspecific variation. They found that the short-leg trait of dogs like dachsunds and basset hounds is caused by a retrogene. Retrogenes are generated by duplication from an existing gene using reverse transcription. It's (presumably) a rare retrotranscription event that produces a working gene copy, but here it is within a single species. There's more going on in the genome than Mendel ever dreamed of.

Remember my post about Luke Harmon's great talk at Evolution2009? Well, his paper (Alfaro et al. 2009) is now available from PNAS. It's interesting stuff, and it's open access. No excuse not to read it.

In other news, Lake's now proposing that "Gram-negative prokaryotes were formed as the result of a symbiosis between an ancient actinobacterium and an ancient clostridium." Endosymbiosis theory run amok or further evidence of widespread modularity in the basic design of organisms?

And for those of you wondering about arthrodire reproduction, there's a new fossil Incisoscutum ritchiei with a well-preserved clasper, indicating internal fertilization. Cool, eh?

Paul Garner posted a summary of the BSG conference on the BCM website. Patrick Keeling credits a creationist for turning him into an evolutionary biologist (which doesn't surprise me in the least). Last but not least, Osborn et al. found some glowing worms.

References

Ahlberg et al. 2009. Pelvic claspers confirm chondrichthyan-like internal fertilization in arthrodires. Nature 460:888-889.

Alfaro et al. 2009. Nine exceptional radiations plus high turnover explain species diversity in jawed vertebrates. PNAS 106:13410-13414.

Keeling. 2009. Creationists made me do it. Science 325:945.

Lake. 2009. Evidence for an early prokaryotic endosymbiosis Nature 460:967-971.

Lynch & Wagner. 2009. Did Egg-Laying Boas Break Dollo's Law? Phylogenetic Evidence for Reversal to Oviparity in Sand Boas (Eryx: Boidae). Evolution DOI 10.1111/j.1558-5646.2009.00790.x.

Osborn et al. 2009. Deep-sea, swimming worms with luminescent "bombs." Science 325:964.

Parker et al. 2009. An expressed Fgf4 retrogene is associated with breed-defining chondrodysplasia in domestic dogs. Science 325:995-998.