Hawthorne D J, Via S
Department of Entomology, University of Maryland, College Park 20742, USA.
Nature. 2001 Aug 30;412(6850):904-7. doi: 10.1038/35091062.
The evolution of ecological specialization generates biological diversity and may lead to speciation. Genetic architecture can either speed or retard this process. If resource use and mate choice have a common genetic basis through pleiotropy or close linkage, the resulting genetic correlations can promote the joint evolution of specialization and reproductive isolation, facilitating speciation. Here we present a model of the role of genetic correlations in specialization and speciation, and test it by analysing the genetic architecture of key traits in two highly specialized host races of the pea aphid (Acyrthosiphon pisum pisum; Hemiptera : Aphididae). We found several complexes of pleiotropic or closely linked quantitative trait loci (QTL) that affect key traits in ways that would promote speciation: QTL with antagonistic effects on performance on the two hosts are linked to QTL that produce asortative mating (through habitat choice). This type of genetic architecture may be common in taxa that have speciated under divergent natural selection.
生态特化的演变产生了生物多样性，并可能导致物种形成。遗传结构既可以加速也可以延缓这一过程。如果资源利用和配偶选择通过基因多效性或紧密连锁具有共同的遗传基础，那么由此产生的遗传相关性可以促进特化和生殖隔离的共同进化，从而推动物种形成。在此，我们提出了一个关于遗传相关性在特化和物种形成中作用的模型，并通过分析豌豆蚜（Acyrthosiphon pisum pisum；半翅目：蚜科）两个高度特化寄主种群关键性状的遗传结构来对其进行检验。我们发现了几个基因多效性或紧密连锁的数量性状基因座（QTL）复合体，它们以促进物种形成的方式影响关键性状：对两种寄主上表现具有拮抗作用的QTL与产生选型交配（通过栖息地选择）的QTL相连。这种遗传结构类型在经历了分歧自然选择而形成物种的分类群中可能很常见。
