Examples of cline

• Overall, the clines tended to be wider the further they were from the race centre.

• Stochastic simulations are necessary for a full understanding of clines in polygenic traits.

• A step cline in a trait determined by an infinite number of unlinked loci.

• However, this is compensated by the narrowing of the clines, which reduces the width of the region over which neutral allele frequencies are steepened.

• However, adjacent clines would tend to annihilate each other, and some mechanism is needed to generate cryptic divergence.

• Moreover, the neutral clines may be curved away from the barrier.

• Genetic drift in clines which are maintained by migration and natural selection.

• Clearly, sampling only a subset of the characters may have failed to reveal the occurrence of non-coincident clines.

• The aim of this paper is to give an overview of the theory for clines in an additive polygenic trait.

• There has been surprisingly little empirical work on the quantitative genetics of clines.

• This level of challenge is a function of the evolving farming system rather than more variable clines such as the degree of tick control.

• However, numerical solutions suggest that the outcome is qualitatively similar, in that a set of scattered clines is maintained.

• This is because for small there is little selection amongst the genotypes found at the centre, and so the clines there are shallow.

• However, these clines may not occur on other continents or in other species.

• Some authors have suggested that mean temperature changes along clines are the main selective factor.