Meeting Abstract
The last 2 million years (Quaternary period) have been a period of dramatic environmental change with major shifts in distributions and abundances of terrestrial and marine organisms. The evolutionary consequences of this were debated during the nineteenth century but the lack of accurate relative and absolute timescales for evolution and environmental change inhibited progress. We do now have an understanding of timescales and detailed palaeoecological work has demonstrated the individualistic nature of species response to environmental change, but lacks a means of determining ancestry. DNA characterization of modern populations in relation to their distributions nicely complements palaeoecological results by contributing ancestry. Both classic palaeoecology and phylogenetics show a remarkable lack of lineage-splitting (speciation) on these timescales, although traditional evolutionary theory leads to the expectation that major environmental changes (such as ice ages) should lead to evolutionary change. This suggests that the factors that lead to lineage-splitting, and hence generation of biodiversity, are more likely to found at the level of population dynamics than in the realm of major environmental changes.
