The rule has been the focus of intense discussion and given much impetus to exploring distributional patterns of plants and animals.
[11] Rohde (1996)[10] explained the fact that the rule is restricted to very high latitudes by effects of glaciations which have wiped out species with narrow ranges, a view also expressed by Brown (1995).
[5][13] According to this hypothesis, seasonal variability selects for greater climatic tolerances and therefore wider latitudinal ranges (see also Fernandez and Vrba 2005[14]).
[8] An additional complication in assessing Rapoport's rule for data based on field sampling is the possibility of a spurious pattern driven by a sample-size artifact.
The tropics have far more uniform temperatures over a far wider latitudinal range (about 45 degrees) than high latitude species.
The inconsistent results concerning Rapoport's rule suggest that certain characteristics of species may be responsible for their different latitudinal ranges.