Department of Zoology, University of Wisconsin, Madison, WI 53706, USA.
Proc Biol Sci. 2011 Sep 7;278(1718):2604-10. doi: 10.1098/rspb.2010.2466. Epub 2011 Jan 26.
During sexual imprinting, offspring learn parental phenotypes and then select mates who are similar to their parents. Imprinting has been thought to contribute to the process of speciation in only a few rare cases; this is despite imprinting's potential to generate assortative mating and solve the problem of recombination in ecological speciation. If offspring imprint on parental traits under divergent selection, these traits will then be involved in both adaptation and mate preference. Such 'magic traits' easily generate sexual isolation and facilitate speciation. In this study, we show that imprinting occurs in two ecologically divergent stickleback species (benthics and limnetics: Gasterosteus spp.). Cross-fostered females preferred mates of their foster father's species. Furthermore, imprinting is essential for sexual isolation between species; isolation was reduced when females were raised without fathers. Daughters imprinted on father odour and colour during a critical period early in development. These traits have diverged between the species owing to differences in ecology. Therefore, we provide the first evidence that imprinting links ecological adaptation to sexual isolation between species. Our results suggest that imprinting may facilitate the evolution of sexual isolation during ecological speciation, may be especially important in cases of rapid diversification, and thus play an integral role in the generation of biodiversity.
在性印记过程中，后代学习亲代表型，然后选择与父母相似的配偶。尽管印记有可能通过产生趋同交配和解决生态物种形成中的重组问题来促进物种形成，但人们认为印记仅在少数几种罕见情况下有助于物种形成。如果后代在不同选择压力下印记亲代特征，这些特征将同时参与适应和配偶偏好。这种“神奇特征”很容易产生性隔离并促进物种形成。在这项研究中，我们表明，印记发生在两个生态差异较大的棘鱼物种（底栖鱼和淡水鱼：Gasterosteus 属）中。被寄养的雌性更喜欢其养父物种的配偶。此外，印记对于物种间的性隔离至关重要；当雌性在没有父亲的情况下饲养时，隔离会降低。女儿在发育早期的关键时期会对父亲的气味和颜色产生印记。由于生态差异，这些特征在物种之间已经分化。因此，我们提供了第一个证据表明印记将生态适应与物种间的性隔离联系起来。我们的研究结果表明，印记可能促进生态物种形成过程中性隔离的进化，在快速多样化的情况下可能尤为重要，因此在生物多样性的产生中起着不可或缺的作用。
