Topic 1: The Pleistocene: Interactions Between Species & Climate

The Pleistocene epoch spanned from about 1.8 million to 10,000 years ago, and has been traditionally believed to be a time of genetic diversification and speciation. Recurring intervals of glacial and interglacial conditions were responsible for redistribution and isolation of both plant and animal species. The changing conditions affected biota in several ways depending on the regional climate: either individual species moved, adapted, or went extinct. The papers we chose deal with several questions that have been raised about the genetic consequences of these changes.

1. Are the ways in which biota adjust to change during the Quaternary, and the magnitude and duration of these climate changes severe enough to cause speciation or extinction? Is there fossil evidence to support this?

2. How do speciation/extinction rates vary regionally over the Earth? How do speciation/extinction rates vary over time, not just during the Pleistocene, but also before?

3. How exactly do refugia and recolonization work? Are coevolutionary relationships more important in determining species distribution than fitness? Are refugia sources of species, or are species lost because not enough resources are available to support them?

Hopefully you will find the papers as interesting as I did, and we will have a great class discussion.