Abstract:
Under incomplete reproductive isolation, secondary contact of diverged allopatric lineages may lead to the formation of hybrid zones that allow to study recombinants over several generations as excellent systems of genomic interactions resulting from the evolutionary forces acting on certain genes and phenotypes. Hybrid phenotypes may either exhibit intermediacy or, alternatively, transgressive traits, which exceed the extremes of their parents due to epistasis and segregation of complementary alleles. While transgressive morphotypes have been examined in fish, reptiles, birds, and mammals, studies in amphibians are rare. Here, we associate microsatellite-based genotypes with morphometrics-based morphotypes of two tree frog species of the Hyla arborea group, sampled across a hybrid zone in Poland, to understand whether the genetically differentiated parental species also differ in morphology between each other and their hybrids and whether secondary contact leads to the evolution of intermediate or transgressive morphotypes. Using univariate approaches, explorative multivariate methods (principal component analyses) as well as techniques with prior grouping (discriminant function analyses), we find that morphotypes of both parental species and hybrids differ from each other. Importantly, hybrid morphotypes are neither intermediate nor transgressive but found to be more similar to H. orientalis than to H. arborea.
摘要:
在不完全的生殖隔离下,不同的异源谱系的二次接触可能导致杂化区的形成,这些杂化区允许研究几代的重组体,作为作用于某些基因和表型的进化力产生的出色的基因组相互作用系统。杂种表型可能表现出中间性或,或者,越轨性特征,由于互补等位基因的上位性和分离,超过了父母的极端。虽然已经在鱼类中检查了过犯的形态类型,爬行动物,鸟,哺乳动物,两栖动物的研究很少见。这里,我们将基于微卫星的基因型与基于形态计量学的Hylaarborea组的两种树蛙物种的形态型相关联,在波兰的一个混合区采样,了解遗传分化的亲本物种彼此之间及其杂种之间的形态是否也存在差异,以及二次接触是否会导致中间或越轨形态类型的进化。使用单变量方法,探索性多变量方法(主成分分析)以及先验分组技术(判别函数分析),我们发现亲本物种和杂种的形态类型彼此不同。重要的是,杂种形态类型既不是中间型也不是越轨型,但发现与东方H.arborea更相似。