Joined: Feb. 2006
|Quote (Daniel Smith @ Sep. 22 2007,14:26)|
|Gradualism is what one would expect to see if the mechanism for evolutionary change were random mutations and natural selection. If you think that it must entail entire populations and their entire geographical range, then fine - show that by the evidence in the fossil record.|
You would only expect to see gradualism if natural selection pressures were relatively constant or changed only slowly. If selective forces change abruptly, would you not also expect to see rapid evolutionary change (and lots of extinctions)? For example, we know that the climate in the past has changed very quickly, for example during shifts between ice ages and interglacial periods.