Ecology and evolution of young species in sympatry

生物多样性在世界各地和加拿大都有很大的不同，为加拿大人发挥着重要的功能和服务。生物多样性是当一个物种的种群彼此分离时形成的，通常是在地理上孤立的(异地隔离)，最终回到第二次接触和重叠(共生)，增加当地和区域的生物多样性。我们研究的重点是次生共生--年轻物种如何共存，以及它们如何影响彼此的生态和进化？这些问题的答案很重要--如果我们要保护生物多样性，我们必须了解生物多样性是如何形成和维持的。拟议研究的具体目标是测试幼年物种之间的二次接触和共生关系对涉及(I)物种识别和(Ii)生态的特征的影响。我们使用鸟类来解决这些问题，因为鸟类的分布、分类和进化关系比任何其他群体都更为人所知。(I)物种识别特征-我们以前的工作记录了当密切相关的鸟类共同生活在一起时，物种识别所涉及的特征(颜色模式和歌声)存在较大差异。我们建议通过比较和实验研究，在可供选择的假说中进行检验，以解释这种模式(杂交、攻击性、信号干扰、通过生态性状进行间接选择)。(Ii)生态特征-我们先前对幼年物种生态学的研究表明，密切相关的鸟类最初使用相似的栖息地并重叠繁殖区域，然后在栖息地使用上出现分歧。我们将测试性格置换假说来解释栖息地的差异，使用实验来检查适应成本和作用在一起生活的年轻物种对的选择压力，这些物种代表了三个不同的鸣禽家族。我们的研究将共同检验年轻物种之间的相互作用在生物多样性形成过程中的重要性，为密切相关物种如何以及如何频繁地影响彼此的生态和进化，以及更广泛地说，密切相关物种之间的相互作用如何促进或限制当地生物多样性提供重要的见解。

Biodiversity varies dramatically across the world and Canada, and performs important functions and services for Canadians. Biodiversity forms when populations of one species diverge from one another, typically in geographic isolation (allopatry), and eventually come back into secondary contact and overlap (sympatry), augmenting local and regional biodiversity. The focus of our research is secondary sympatry - how do young species live together, and how do they influence each other's ecology and evolution? An answer to these questions is important - we must understand how biodiversity forms and is maintained if we are to protect it. The specific objective of the proposed research is to test the consequences of secondary contact and sympatry among young species for traits involved in (I) species recognition and (II) ecology. We use birds to address these questions because the distribution, taxonomy, and evolutionary relationships of birds are better known than any other group. (I) Species Recognition Traits - Our previous work documented greater divergence in traits involved in species recognition (colour patterns and songs) when closely related species of birds live in sympatry. We propose to test among alternative hypotheses to explain this pattern (hybridization, aggression, signal interference, indirect selection through ecological traits) using comparative and experimental studies. (II) Ecological Traits - Our previous work on the ecology of young species suggests that closely related birds initially use similar habitats and overlap breeding territories, and then subsequently diverge in habitat use. We will test the Character Displacement Hypothesis to explain habitat divergence, using experiments to examine fitness costs and selective pressures acting on pairs of young species that live together, representing three distinct families of songbirds. Together, our research will test the importance of interactions among young species during the formation of biodiversity, providing important insights into how and how often closely related species influence each others' ecology and evolution, and, more broadly, how interactions among closely related species promote or constrain local biodiversity.