Adaptive radiation along genetic lines of least resistance

摘要: Are measurements of quantitative genetic variation useful for predicting long-term adaptive evolution? To answer this question, I focus on gmax, the multivariate direction greatest additive variance within populations. Original data threespine sticklebacks, together with published from other vertebrates, show that morphological differentiation between species has been biased in gmax at least four million years, despite evidence natural selection is cause differentiation. This bias toward evolution tends to decay time. Rate divergence inversely proportional 0, angle and variation. The phenotypic not identical but these nearly as successful divergence. interpret findings mean variances covariances constrain change traits reasonably long spans An alternative hypothesis, however, cannot be ruled out: because are both shaped by same pressures. Either way, results reveal occurs principally along "genetic lines resistance."