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

Evolution, thus, is merely contingent on certain processes articulated by Darwin: variation and selection. No longer is a fixed object transformed, as in transformational evolution, but an entirely new start is, so to speak, made in every generation.

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.

Evolution ... is opportunistic, hence unpredictable.

Biology can be divided into the study of proximate causes, the study of the physiological sciences (broadly conceived), and into the study of ultimate (evolutionary) causes, the subject of natural history.

It seems to me that for Darwin the pulsing of evolutionary rates was a strictly vertical phenomenon.

According to the concept of transformational evolution, first clearly articulated by Lamarck, evolution consists of the gradual transformation of organisms from one condition of existence to another.