David Conover and Eric Schultz are at the Marine Sciences Research Center, State University of New York, Stony Brook, NY 11794-5000, USA.
Trends Ecol Evol. 1995 Jun;10(6):248-52. doi: 10.1016/S0169-5347(00)89081-3.
Countergradient variation is a geographical pattern of genotypes (with respect to environments) in which genetic influences on a trait oppose environmental influences, thereby minimizing phenotypic change along the gradient. Phenotypic similarity across changing environments ought to be of intense interest because it belies considerable genotypic change. When it occurs in characters that are positively associated with fitness, countergradient variation conflicts with the hypothesis that local adaptation to one environment trades off against performance in another environment. Cases of countergradient variation therefore offer unique insight into the mechanisms that produce and maintain phenotypic similarity and/or differences along environmental gradients.
反梯度变异是基因型的地理模式（相对于环境），其中性状的遗传影响与环境影响相反，从而使沿梯度的表型变化最小化。表型在变化环境中的相似性应该是非常有趣的，因为它掩盖了相当大的基因型变化。当它发生在与适应性呈正相关的特征上时，反梯度变异与局部适应一个环境而牺牲在另一个环境中的表现的假设相冲突。因此，反梯度变异的情况为产生和维持表型相似性和/或沿环境梯度差异的机制提供了独特的见解。
