Dissertation Research: The Role of Hybridization in the Evolution and Diversification of Heliconius Butterflies

进化研究的主要目标之一是解释新物种起源的机制。其中一个相对较少受到关注的机制是，由于先前建立的物种之间的杂交(或通过种间杂交形成物种)而形成新物种。为了了解新物种是如何通过杂交产生的，这个项目将追溯最近通过杂交产生的热带蝴蝶物种帕奇努斯和它的亲本物种之一希德诺之间的分歧历史。这是假设，自从起源的H.pachinus形式，自然选择已导致进化的机制，维持物种的完整性。这个项目将通过研究这些机制并通过比较这两个物种在整个范围内的遗传构成来确定这两个物种之间发生了多少总体基因交换。尽管杂交在动物进化中的作用比以往任何时候都受到更多的关注，但通过杂交在动物身上形成物种的明显例子很少。一旦完成，这项研究将提供最完整的杂交物种形成解释之一。此外，这里提出的分化机制是一个新的和令人兴奋的过程，通过这个过程，物种形成可能在这个属和其他属中发生了多次。长期以来，模仿赫利柯乌斯物种对令人难以置信的对应关系一直令生物学家感到惊讶，但仍然缺乏机械论的解释。这里提出的假设很可能是对整个现象的解释。

One of the primary goals of evolutionary research is to explain the mechanisms by which new species originate. One such mechanism that has received relatively little attention is the formation of new species due to interbreeding between previously established species (or, speciation via interspecific hybridization). In an effort to understand how new species originate due to hybridization, this project will trace the history of divergence between Heliconius pachinus, a tropical butterfly species that recently originated via hybridization, and one of its parental species, H. cydno. It is hypothesized that since the origin of the H. pachinus form, natural selection has led to the evolution of mechanisms by which species integrity is maintained. This project will determine how much overall genetic exchange is occurring between these two species by examining these mechanisms and by comparing the genetic makeup of both species throughout their range.Although the role of hybridization in animal evolution is receiving more attention than ever, there are few clear examples of speciation via hybridization in animals. Once finished, this study will provide one of the most complete explanations of speciation via hybridization. Furthermore, the mechanism of divergence proposed here is a novel and exciting process by which speciation may have occurred many times in this genus and others. The incredible correspondence of mimetic Heliconius species pairs has long amazed biologists and still lacks a mechanistic explanation. The hypothesis put forward here could well be the explanation for this entire phenomenon.