Given the fact of evolution, one would expect the fossils to document a gradual steady change from ancestral forms to the descendants. But this is not what the paleontologist finds. Instead, he or she finds gaps in just about every phyletic series.

In neither his definition nor the examples illustrating what memes are does Dawkins mention anything that would distinguish memes from concepts.

Wherever we look at the living biota … discontinuities are overwhelmingly frequent…The discontinuities are even more striking in the fossil record. New species usually appear in the fossil record suddenly, not connected with their ancestors by a series of intermediates.

A new species develops if a population which has become geographically isolated from its parental species acquires during this period of isolation characters which promote or guarantee reproductive isolation when the external barriers break down.

Evolution thus is merely contingent on certain processes articulated by Darwin: variation and selection.

There are a number of attributes of species and populations that are not of any particular selective advantage to any single individual in a population but that are of great advantage to the population as a whole.

Isolating mechanisms are biological properties of individuals that prevent the interbreeding of populations that are actually or potentially sympatric.