To kick start some blogging on the latest research that I find interesting and exciting, two recent papers examine speciation and extinction rates in carnivores using extensive data sets on fossil occurrences.
One of the best ways to estimate the past diversification dynamics (speciation and extinction rates) is using the rock record - fossils preserve the timing and location of speciation and extinction events. Other ways that are informative include using the evolutionary tree of living species, because the structure of the tree reflects past speciation patterns. But more on that another day...
Using a sophisticated biological model of speciation and extinction dynamics that includes preservation bias (the rock record is not perfect!), Pires, Silvestro and Quental inferred rates for each carnivore family, including entirely extinct groups, and found strong evidence for rapid and exceptional speciation when carnivores moved from North America to Eurasia, an example of adaptive radiation.
Reconstructing the waxing and waning diversification of carnivores can test hypotheses about the biogeography and environmental causes of speciation and extinction in deep time.
Next, Silvestro and colleagues step it up even further to test the effects of past competition and climate change on the speciation and extinction rates of North American fossil canids: http://www.pnas.org/content/112/28/8684.short
I've got to go over this second paper in more detail (don't you love it when the article is 6 pages but the online supplemental information is 60?). But it seems like a really innovative look at the Red Queen hypothesis - that species evolve as fast as they can to just to stay in one place...to keep pace with a changing environment. Previous research has shown that the failure to keep pace with the changing environment has driven species to extinction: http://www.sciencemag.org/content/341/6143/290.short
One of the projects I'll be working on for my postdoc at the AMNH is this kind of analysis for all primates. I'm still working on the first step - assembling the fossil occurrence data. It takes time and screening the data for the 'perfect' ages is no easy chore. But hopefully this project will move forward quickly.