This chapter reviews evidence for evolutionary change in relation to the pace of climatic change. Most examples come from the late-Quaternary as the most accessible period of time for consideration of changes on Milankovitch time-scales, short by geological standards, but long ecologically. The chapter addresses directly the question that Lyell put to Darwin (see page 9), by considering whether or not the fossil record supports a notion of continual change, and hence that processes in operation today can be extrapolated back through all of time (substantative uniformitarianism), or a notion of disruption of ecological patterns on long time-scales, in which case no extrapolation is possible.

The evolutionary response of populations to climatic changes may, in principle, have taken place on a variety of time-scales. Populations might change gradually, through adaptation (Darwinian natural selection) or by any other cause, possibly to the extent that new species could be considered to have evolved (phyletic gradualism). Lineages might split to establish allopatric populations with sufficient new characteristics to form new species (cladogenesis). Populations (and species, when all constituent populations are lost) might become extinct. There may be no evolutionary change at all (stasis).

The quality of evidence needed to show that evolutionary change has taken place in response to climatic changes on Milankovitch time-scales is demanding. Ideally, time, place, and rate of change are needed from data with a temporal resolution of less than 10 kyr, and this is rarely available.