Mechanisms of diversification in North American frogs

北美青蛙的多样化机制

• 批准号: 238462-2006
• 负责人: Lougheed, Stephen
• 金额: $ 2.26万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=393938
• 关键词: Mechanisms; diversification; North; American; frogs

Despite over six decades of research, a complete understanding of the mechanisms that generate species diversity remains elusive. Recently developed molecular tools and analytical methods afford us excellent opportunities to answer outstanding questions on the process of speciation. We address two of these using field and genetic studies of a small North American frog, the spring peeper. Our previous work identified major evolutionary lineages that have come into secondary contact in the northern portion of the species range after long periods of geographical isolation. For our first project, we will use a range of molecular and experimental approaches to test whether three pairs of divergent lineages now in secondary contact show evidence of reproductive isolation (a hallmark of speciation): reduction of ability to produce viable offspring, and divergence in male advertisement calls and female receptivity to them. Evidence of reproductive isolation will indicate that historical separation of populations may provide opportunity for divergence, but offers no insight as to its cause. Our second project will examine the proximate mechanisms that may cause such divergence. Specifically within an environmentally heterogeneous 4000 sq. km. area in Eastern Ontario, we will test whether selection pressures in habitats differing in vegetation structure and microclimate can produce significant differences in (1) spring emergence and calling by males, and (2) the acoustic properties of male advertisement calls. The combined insights from these projects will significantly advance our knowledge of the importance of, and interplay among, geographical isolation, contact zone dynamics, and ecological selection in diversification and speciation.

尽管经过了60多年的研究，但对物种多样性产生机制的完整理解仍然难以捉摸。最近发展起来的分子工具和分析方法为我们提供了很好的机会来回答物种形成过程中的突出问题。我们利用对北美一种小型青蛙--春季偷窥者的实地和基因研究，解决了其中的两个问题。我们之前的工作确定了在长期的地理隔离之后，在物种范围的北部进入二次接触的主要进化谱系。在我们的第一个项目中，我们将使用一系列分子和实验方法来测试目前处于二次接触的三对不同的谱系是否显示出生殖隔离的证据(物种形成的一个标志)：产生可存活后代的能力降低，以及男性广告呼叫和女性对它们的接受度的差异。生殖隔离的证据将表明，历史上的种群分离可能提供了分化的机会，但没有提供对其原因的洞察。我们的第二个项目将研究可能导致这种差异的最接近的机制。尤其是在环境不同的4000平方英尺内。公里。在安大略省东部地区，我们将测试在不同植被结构和小气候的生境中的选择压力是否会在(1)雄性的春季出现和叫声，以及(2)雄性广告叫声的声学特性方面产生显著差异。这些项目的综合见解将大大提高我们对地理隔离、接触带动态以及生态选择在多样化和物种形成中的重要性和相互作用的认识。