The number of counterfolds in the molariform teeth vary in clinal fashion.
clinal variation, from north to south, is shown in the decreasing length of the nasals.
No clinal variation in diameter of the guard hairs was detected.
The number of pale specimens in any given series decreases gradually in a clinal pattern from west to east.
Geographic variation in these measurements is clinal in some species.
One of the species of Trinomys, Proechimys iheringi, is here subdivided into six subspecies which show a clinal variation.
clinal variation correlated with increasing humidity is to be seen also in longer tail and darker color of pelage.
A gradual change in an inherited characteristic across the geographic range of a species, usually correlated with an environmental transition such as altitude, temperature, or moisture. For example, the body size in a species of warm-blooded animals tends to be larger in cooler climates (a latitudinal cline), while the flowering time of a plant may tend to be later at higher altitudes (an altitudinal cline). In species in which the gene flow between adjacent populations is high, the cline is typically smooth, whereas in populations with restricted gene flow the cline usually occurs as a series of relatively abrupt changes from one group to the next.