Charmantier Anne, Kruuk Loeske E B, Lambrechts Marcel M
Centre d'Ecologie Fonctionnelle and Evolutive, Centre National de la Recherche Scientifique, 1919 Route de Mende, F-34293 Montpellier Cedex 5, France.
Evolution. 2004 Jan;58(1):203-6. doi: 10.1111/j.0014-3820.2004.tb01588.x.
We tested the effect of detrimental environmental conditions during growth on the heritability of chick body size in a wild population of blue tits (Parus caeruleus) highly parasitized by blowfly larvae. During nine years, we experimentally induced deparasitized broods, whereas unmanipulated control broods remained heavily infested by two species of Protocalliphora ectoparasites. The heritability of tarsus length was significantly higher in deparasitized broods than control broods, due in part to a very low common brood environment effect in deparasitized broods. We also found evidence for significant genotype-by-environment interactions, which further reflected the effect of the ecological conditions on the expression of additive genetic effects and could represent an additional constraint on the evolution of tarsus length. To our knowledge, this experiment provides the first evidence of host quantitative genetics being influenced by parasitism, and illustrates the potential for parasitism to constrain an evolutionary response to selection.
我们测试了在蓝山雀（Parus caeruleus）的野生种群中，生长期间不利的环境条件对雏鸡体型遗传力的影响，该种群受到蝇幼虫的高度寄生。在九年的时间里，我们通过实验诱导了无寄生虫的巢，而未进行处理的对照巢则仍然受到两种原丽蝇外寄生虫的严重侵扰。无寄生虫巢中跗骨长度的遗传力显著高于对照巢，部分原因是无寄生虫巢中共同巢环境效应非常低。我们还发现了显著的基因型与环境相互作用的证据，这进一步反映了生态条件对加性遗传效应表达的影响，并且可能代表了对跗骨长度进化的额外限制。据我们所知，该实验首次提供了宿主数量遗传学受寄生影响的证据，并说明了寄生对选择进化反应的潜在限制。
