Evolutionary and Conservation Genetics of Reptiles

爬行动物的进化和保护遗传学

• 批准号: 3148-2013
• 负责人: Murphy, Robert
• 金额: $ 1.97万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=520547
• 关键词: Evolutionary; Conservation; Genetics; Reptiles

Closely related females of wild species of animals are often found side-by-side rather than being broadly mixed with more distantly related females of the same species. A narrow geographic break separates females of more distant lineages. The region where both lineages occur may be only 6km or less. Curiously, on the narrow peninsula of Baja California, Mexico, most species of animals show a pattern of neighbouring lineages in the middle of the peninsula. These have lived side-by-side for more than 3 million years without mixing and in some cases for much longer periods of time. A key focus of my research is to determine why this common pattern is so universal among animals. In other words, why do females not disperse more than 6km given more than 3 million years to do so? After all, this distance amounts to only 2mm/year! One explanation, termed cytonuclear discordance, suggests that the lineages do not mix because their energy-producing enzymes do not work efficiently when they are mixed. By analogy, this phenomenon is like trying to put a square peg of one lineage into a round hole of another. Another possibility is that females protect their families against intruders, and this novel explanation, which is analogous to battle-lines, I call the sisterhood hypothesis. To make the situation complex, both of these explanations may work together in concert to maintain the pattern. I will use a suite of experiments with tree lizards to evaluate cytonuclear discordance, the sisterhood hypothesis, and the relative roles played by each of these mechanisms in maintaining the pattern of side-by-side maternal lineages. The experiments range from determining the relatedness of females on a given tree, be they mother-daughter, sisters, cousins, or more distantly related, and sophisticated models of protein structure to evaluate how the enzymes work together. The analyses have implications for not only understanding how species evolve, but also for conservation and management initiatives, especially as they relate to species translocations.

野生动物物种中近亲的雌性动物通常是并排发现的，而不是广泛地与同一物种的远亲雌性动物混在一起。一条狭窄的地理分界线将更远血统的女性分开。这两个谱系出现的区域可能只有6公里或更少。奇怪的是，在墨西哥下加利福尼亚州狭窄的半岛上，大多数动物物种在半岛中部显示出相邻谱系的模式。它们并肩生活了300多万年，没有混合，在某些情况下，时间更长。我研究的一个重点是确定为什么这种常见模式在动物中如此普遍。换句话说，为什么女性不分散超过6公里，因为超过300万年了？毕竟，这个距离每年只有2毫米！一种被称为细胞核不协调的解释表明，谱系不能混合，因为它们的能量产生酶在混合时不能有效地工作。打个比方，这种现象就像试图把一个血统的方栓插入另一个血统的圆孔。另一种可能性是，女性保护她们的家庭免受入侵者的侵害，这种新颖的解释，类似于战线，我称之为姐妹关系假说。为了使情况变得复杂，这两种解释可能会一起协调工作，以维持模式。我将使用一套实验树蜥蜴来评估细胞核不一致，姐妹假说，以及这些机制中的每一个在维持并排母系模式中所扮演的相对角色。这些实验包括确定给定树上雌性动物的亲缘关系，无论是母女、姐妹篇、堂兄弟姐妹还是远亲，以及复杂的蛋白质结构模型，以评估酶如何协同工作。这些分析不仅对了解物种如何进化有影响，而且对保护和管理举措也有影响，特别是当它们与物种易位有关时。