 Some points to note here that become relevant in later discussions of drift: 1) Drift is described in contrast to natural selection. 2) The variations increasing in the population are those that are neutral, or at least not severely deleterious. (Note that 1 and 2 are also present in the quote from Darwin above). 3) Drift is associated with small populations (although it is not fully clear why). 4) Drift is associated with the founding of a new population in a new area. 5) Changes in the population are the result of movements of organisms and their tendency to produce new variations, both of which are physical processes and not purely mathematical constructs (something that becomes an issue in later debates). 6) The changes described are of organisms in a population.