by Greg Mayer There have been a number of interesting comments by readers on my post on the recent paper on the radiation of placental mammals by Maureen O’Leary and colleagues. I want to respond briefly to a few of them here. Biogeography. Does this paper imply that the origin and geographic distribution of the […]
by Greg Mayer (Updates below.) A new study just published in Science by Maureen O’Leary and colleagues examines the phylogeny of 40 fossil and 46 extant mammals based on a very large data set of morphological and molecular characters (the latter only from the living taxa). The study has gotten a fair amount of attention […]
by Greg Mayer Although the mammals and reptiles most people know are quite distinct– mammals are hairy, warm-blooded, live-bearers, that suckle their young, while reptiles are scaly, cold-blooded, egg-layers– a wider knowledge of the modern forms reveals that the differences are less absolute. There are many live-bearing reptiles, for example, and platypuses and echidnas lay […]
