Quick hits

The platypus genome put me in the mood for more evolutionary biology, so here are some interesting recent papers of an evolutionary bend (note: Abstracts available, but subscription or "pay-per-view" needed for full article access. Sorry.):

Amino acid sequence data from collagen extracted from the bones of Tyrannasaurus rex and the mammoth, Mammut americanum, were used to build a phylogeny of these two species. As expected, based on previous phylogenetic work, M. americanum groups with modern elephants and T. rex groups with modern birds (chickens to be exact). This paper builds on earlier success in using protein sequences to elucidate evolutionary history of extinct organisms.

Hermaphoditism evolves when mate-search efficiency is poor. In other words, if ... you ... move ... really ... slowly ... and ... don't come across another individual of your species all that often, it's best to be prepared when you do - it would really suck to look all that time for a mate only to come across an individual of the same sex and have to start the search all over again.

Analysis of oxygen isotope levels in the tooth enamel of extinct relatives of elephants suggest that modern probocidians evolved from aquatic or semi-aquatic forms. This is expected given the close phylogentic relationship between extant elephants and the sirenians (manatees and dugongs) and provides new arguments for the idea that elephant trunks may have originally evolved as a snorkel.