Collaborative Research: Testing Measures of Evolvability: Adaptation and Genetic Constraints in Dalechampia Vines (Euphorbiaceae)

遗传变化是生物进化和多样化的主要主题，但令人惊讶的是，对于哪些性状和生物体最有可能在自然选择和环境变化中经历基因频率的重大变化，我们知之甚少。对可遗传性状变化的实证研究依赖于对潜在变化的可操作测量，这种潜在变化反映了性状在相关性状稳定或相反选择的约束下对给定外部选择压力的反应能力。研究人员认为，加性遗传变异以相关性状为条件，并按性状平均值的平方进行缩放，即“有条件的遗传变异”，比传统的“遗传能力”更能衡量短期变化。他们将使用这些新的测量方法来测试关于遗传限制在决定Dalechampia（一种新热带藤蔓植物）花朵大规模变异模式中的作用的假设。他们将结合人工选择和实地实验来记录进化的潜力和自然选择的模式。该项目将促进我们对生物如何在自然选择中进化的理解，并可能应用于了解植物对气候变化的反应、作物育种以及农药和药物耐药性的起源。该项目将培养2名博士后、1名硕士生和数名本科生。它还将促进美国、挪威、英国和几个拉丁美洲国家之间的国际合作。

Genetic change is a dominant theme in the evolutiona and diversification of organisms, yet surprisingly little is known about which traits and organisms are most likely to undergo major shifts in gene frequency in response to natural selection and environmental change. Empirical study of change in heritable traits depends on having an operational measure of potential change that reflects the ability of a trait to respond to a given external selection pressure under the constraint of stabilizing or opposing selection on correlated characters. The investigators suggest that the additive genetic variance conditioned on correlated traits and scaled by the square of the trait mean, "conditional IA," is a better measure of short-term change than the traditional measure, "heritability." They will use these new measures to test hypotheses about the role of genetic constraints in determining large-scale patterns of variation in the blossoms of Dalechampia, a neotropical vine. They will use a combination of artificial-selection and field experiments to document potential for evolution and patterns of natural selection. This project will advance our understanding of how organisms evolve in response to natural selection, with possible applications to understanding response of plants to climate change, crop breeding, and the origins of pesticide and drug resistance. The project will train two postdoctoral researchers, one master's student, and several undergraduate students. It will also promote international collaboration between the USA, Norway, the United Kingdom, and several Latin American countries.