Parzer Harald F, Moczek Armin P
Department of Biology, Indiana University, Bloomington, Indiana, USA.
Evolution. 2008 Sep;62(9):2423-8. doi: 10.1111/j.1558-5646.2008.00448.x. Epub 2008 Jul 4.
Different structures may compete during development for a shared and limited pool of resources to sustain growth and differentiation. The resulting resource allocation trade-offs have the potential to alter both ontogenetic outcomes and evolutionary trajectories. However, little is known about the evolutionary causes and consequences of resource allocation trade-offs in natural populations. Here, we explore the significance of resource allocation trade-offs between primary and secondary sexual traits in shaping early morphological divergences between four recently separated populations of the horned beetle Onthophagus taurus as well as macroevolutionary divergence patterns across 10 Onthophagus species. We show that resource allocation trade-offs leave a strong signature in morphological divergence patterns both within and between species. Furthermore, our results suggest that genital divergence may, under certain circumstances, occur as a byproduct of evolutionary changes in secondary sexual traits. Given the importance of copulatory organ morphology for reproductive isolation our findings begin to raise the possibility that secondary sexual trait evolution may promote speciation as a byproduct. We discuss the implications of our results on the causes and consequences of resource allocation trade-offs in insects.
在发育过程中，不同的结构可能会竞争共享且有限的资源库，以维持生长和分化。由此产生的资源分配权衡有可能改变个体发育结果和进化轨迹。然而，对于自然种群中资源分配权衡的进化原因和后果，我们知之甚少。在这里，我们探讨了在塑造角甲虫Onthophagus taurus最近分离出的四个种群之间的早期形态差异以及10种Onthophagus物种的宏观进化差异模式时，初级和次级性征之间资源分配权衡的重要性。我们表明，资源分配权衡在物种内部和物种之间的形态差异模式中都留下了强烈的印记。此外，我们的结果表明，在某些情况下，生殖器差异可能作为次级性征进化变化的副产品而出现。鉴于交配器官形态对于生殖隔离的重要性，我们的发现开始提出这样一种可能性，即次级性征进化可能作为副产品促进物种形成。我们讨论了我们的结果对昆虫资源分配权衡的原因和后果的影响。
