Comparative Quantitative Genetics

正如一系列特征可能会进化一样，影响这些特征表达的遗传系统也可能会进化。许多研究都很好地理解了容易观察到的特征的进化，如身体大小、大脑大小等。我们知道这些可观察到的特征进化得有多快(或多慢)。然而，关于遗传系统的基本进化事实几乎是未知的，尽管它们对现代进化理论很重要。我们不知道继承制度演变得有多快。一组可观察到的性状的遗传系统是通过测量父母和他们的后代之间对这些性状的相似程度来评估的。要评估任何特定种群的遗传系统，我们必须衡量许多父母和后代的相似性。每个种群或物种需要大量的亲属样本，这阻碍了遗传的比较研究。拟议的项目将使用动物(吊袜带蛇和水蛇)，在这些动物中，父母及其后代的大样本可以很容易地组装起来。这些动物还有一个进一步的优势，那就是从生化研究中已经知道了进化关系。因此，可以比较近亲和远亲物种之间的遗传系统，并确定进化的速度。现代进化论经常假设，继承系统进化得如此之慢，以至于它们实际上是不变的。拟议的项目将是对这一关键假设在生物自然种群中的第一次强有力的考验。

Just as ensembles of traits may evolve, so may the system of inheritance that affects the expression of those traits. The evolution of readily observable traits such as body size, brain size, etc. is well understood from numerous studies. We know how rapidly (or slowly) such observable traits evolve. Basic evolutionary facts about systems of inheritance, however, are virtually unknown, despite their importance to modern evolutionary theory. We do not know how rapidly the inheritance system evolves. The system of inheritance for a set of observable traits is assessed by measuring the degree of resemblance between parents and their offspring for those traits. To assess the inheritance system of any particular population, we must measure resemblance in many sets of parents and offspring. The necessity of a large sample of relatives in each population or species has frustrated comparative studies of inheritance. The proposed project will use animals (garter snakes and water snakes) in which large samples of parents and their offspring can be readily assembled. These animals have the further advantage that evolutionary relationships are already known from biochemical work. Consequently, systems of inheritance can be compared among closely and distantly related species and rates of evolution can be determined. Modern evolutionary theory often assumes that systems of inheritance evolve so slowly that they are effectively invariant. The proposed project will constitute the first strong test of that critical assumption in natural populations of organisms.