Change in population characteristics over a geographical area, usually related to a corresponding environmental change.
A gradual shift in gene frequencies between neighboring populations.
a geographic gradient in the frequency of a gene, or in the average value of a character
a gradient of change, such as from people with a high frequency of blue eyes, as in Scandinavia, to people with a high frequency of brown eyes, as in Africa
a gradual change in gene frequency in a population
a gradual change in (often) morphology from one area to another
a relatively regular change in a biological trait over a stretch of territory
a single trait genetic gradient, not a group, but a gradient over space and different environments
A gradual change over a wide geographic range in a species' appearance (size, colour, markings, etc.).
Slight change in physical appearance from one geographical region to another
Gk. klinein, to lean] Variation in features of individuals in a population that parallels a gradient in the environment.
A gradual morphological or physiological change in a group of related organisms across their range, usually associated with environmental or geographic transition.
A gradual change in an allele frequency or in the mean of a character over a geographic boundary.
In population genetics, a cline is a gradual change of a character or feature (phenotype) in a species over a geographical area, often as a result of environmental heterogeneity. The change in phenotype does not result in different species as long as the geographically spread populations can interbreed with one another. This meaning of cline was introduced by Sir Julian Huxley.