Domestication and fitness in the wild: A multivariate view

Domesticated species continually escaping and interbreeding with wild relatives impose a migration load on wild populations. As domesticated stocks become increasingly different as a result of artificial and natural selection in captivity, fitness of escapees in the wild is expected to decline, reducing the effective rate of migration into wild populations. Recent theory suggest that this may alleviate and eventually eliminate the resulting migration load. I develop a multivariate model of trait and wild fitness evolution resulting from the joint effects of artificial and natural selection in the captive environment. Initially, the evolutionary trajectory is dominated by the effects of artificial selection causing a fast initial decline in fitness of escapees in the wild. In later phases, through the counteracting effects of correlational multivariate natural selection in captivity, the mean phenotype is pushed in directions of weak stabilizing selection, allowing a sustained response i...

驯化物种持续逃逸并与野生近缘种杂交，会对野生种群施加迁移负荷。随着驯化种群因圈养环境下的人工选择与自然选择愈发分化，逃逸个体在野生环境中的适合度预计会下降，进而降低向野生种群的有效迁移率。近期理论研究表明，这一过程或可缓解并最终消除由此产生的迁移负荷。本文构建了一个多变量模型，用以刻画圈养环境中人工选择与自然选择共同作用下的性状演化与野生适合度动态。在演化初期，人工选择的效应占据主导，致使逃逸个体的野生适合度出现快速初始下降。在后续阶段，圈养环境下的相关性多变量自然选择会产生抵消效应，将平均表型推向弱稳定选择的方向，从而使响应得以持续……