Evolution of Maternal Effects in a Model Avian System

进化生物学的一个核心原则是自然选择导致适应。对蒙大拿州和阿拉巴马州的家雀的研究证明，这些鸟类确实已经迅速适应了当地的环境，尽管它们只是在过去几十年才在这些生态高度不同的地区定居。局部适应包括男性和女性不同的大小和形状，但这些变化发生得太快，不能仅用基于基因的变化来解释。此前已经有文献证明，在蒙大拿州和阿拉巴马州，雄性和雌性家雀生长和发育方式的快速变化是造成种群差异的原因。特别是雄性和雌性在产卵顺序中被分配到不同的位置，以及产卵顺序对生长和发育的强烈和特定性别的影响，导致了种群的迅速变化。这种母性效应如何影响男性和女性的成长是本研究的重点。这项调查将测试雌性分配的激素，如睾酮和催乳素，特定的营养物质，如类胡萝卜素和脂肪，鸡蛋的总体营养含量，或卵孵化的时间是否在产卵顺序上有所不同，以及这些因素如何影响雄性和雌性后代的生长和发育。我们的研究对于更好地理解自然选择如何导致快速适应当地环境是至关重要的。调整雄性和雌性的生长模式以适应当地环境的能力，可能使家雀和其他一些入侵脊椎动物物种能够在非常独特和不断变化的环境中定居。

A central tenet of evolutionary biology is that natural selection leads to adaptation. Studies of house finches in Montana and Alabama have documented that indeed, these birds have rapidly adapted to the local environment, despite having colonized these highly ecologically distinct areas only in the last few decades. Local adaptations include different sizes and shapes for males and females but these changes have occurred too rapidly to be explained by genetically based changes alone. It has been documented previously that rapid changes in how male and female house finches grow and develop in Montana and Alabama are responsible for differences between the populations. In particular it is the allocation of males and females to different positions in the laying order and strong and sex-specific effects of laying order on growth and development that led to rapid changes in the populations. How such maternal effects can affect the growth of males and females is the focus of this study. This investigation will test whether female allocation of hormones such as testosterone and prolactin, specific nutrients such as carotenoids and lipids, overall nutrient content of eggs, or the timing of egg incubation varies across laying order and how each of these factors affects the growth and development of male and female offspring. Our investigation is fundamental to a better understanding of how natural selection can lead to rapid adaptation to local environments. The ability to adjust the growth patterns of males and females as an adaptation to local environments may have enabled the house finch and some other invasive vertebrate species to colonize highly distinct and changing environments.