There is a couple of interesting new papers just published on the subject of speciation. In BMC Evolutionary Biology, Brown et al. report a molecular phylogeny of mastacembelid eels focusing expecially on eels from Lake Tanganyika. They found that the Tanganyika species are indeed monophyletic, supporting the inference of yet another species radiation in the lake. The most famous of these radiations is the Cichlidae, which are at least as common in the textbooks as Darwin's finches. Lake Tanganyika is also home to an unusual number of species radiations, including Platythelphusa crabs, Synodontis catfish, and Cyprideis ostracods, among others. Must be something in the water...
On a completely different note, PNAS has a new paper from Larsen et al. on a fascinating Caribbean bat, Artibeus schwartzi. It seems that the nuclear genome of Artibeus schwartzi came from two other species (A. jamaicensis and A. planirostris), and its mitochondrial genome is derived from a third, unknown species. Larsen et al. interpret these results as indicating that A. schwartzi is of hybrid origin, which is weird. Hybrid speciation happens all the time in plants, but it's nearly unheard of in mammals. Check it out for yourself, the paper is open access.
Brown et al. 2010. Mastacembelid eels support Lake Tanganyika as an evolutionary hotspot of diversification. BMC Evolutionary Biology 10:188.
Larsen et al. 2010. Natural hybridization generates mammalian lineage with species characteristics. PNAS 107:11447-11452.
Feedback? Email me at toddcharleswood [at] gmail [dot] com.