Data from: Genetic constraints predict evolutionary divergence in Dalechampia blossoms

If genetic constraints are important, then rates and direction of evolution should be related to trait evolvability. Here we use recently developed measures of evolvability to test the genetic constraint hypothesis with quantitative genetic data on floral morphology from the Neotropical vine Dalechampia scandens (Euphorbiaceae). These measures were compared against rates of evolution and patterns of divergence among 24 populations in two species in the D. scandens species complex. We found clear evidence for genetic constraints, particularly among traits that were tightly phenotypically integrated. This relationship between evolvability and evolutionary divergence is puzzling, because the estimated evolvabilities seem too large to constitute real constraints. We suggest that this paradox can be explained by a combination of weak stabilizing selection around moving adaptive optima and small realized evolvabilities relative to the observed additive genetic variance.若遗传限制（genetic constraint）发挥关键作用，则演化的速率与方向应当与性状进化潜能（evolvability）相关。本文采用新近开发的进化潜能测度方法，结合来自新热带藤本植物Dalechampia scandens（大戟科Euphorbiaceae）的花形态数量遗传数据，对遗传限制假说开展检验。本研究以D. scandens物种复合群中2个物种的24个种群为研究对象，将上述进化潜能测度结果与演化速率及分化模式进行对比分析。研究结果为遗传限制假说提供了明确的支撑证据，尤其在表型整合度较高的性状组中更为显著。然而，进化潜能与演化分化间的这一关联却存在矛盾：估算得到的进化潜能数值过大，似乎难以构成真正的遗传限制。本文提出，该悖论可通过以下两种机制共同解释：一是围绕移动的自适应最适值的弱稳定选择，二是相较于观测到的加性遗传方差，实际实现的进化潜能较小。