Mechanisms of convergent flower color evolution above and below the species level

这个项目将调查进化是否可以在基因水平上预测。表型趋同，即在独立谱系中出现相似形式，为测试遗传进化的可预测性提供了机会。不同谱系中相似的表型往往是由于遗传水平上相似的变化。一种可能的解释是，在产生特定表型的可能机制中，一些遗传变化在进化过程中被优先固定。本项目将通过比较种属水平上和种属水平下白花颜色的遗传基础来检验优先固定假说。中心假设预测，在色素物种中，大量的突变将导致白花突变，但在物种水平上，从色素到白花的转变过程中，这些突变类别中只有一小部分是固定的。利用马铃薯科的一组物种，PI将采用遗传，发育和生化方法的组合来验证这一预测。这些结果将有助于更好地理解微观进化和宏观进化变化之间的关系。这些研究将对控制和提高园艺品种和作物的色素含量具有重要意义。植物色素，包括该项目所针对的那些，是强抗氧化剂，有助于丰富水果和蔬菜饮食的积极健康益处。因此，更好地了解遗传变化如何影响色素生物合成增加了改良作物物种的潜力。该项目包括为K-12年级学生举办的当地外联活动，以促进对植物进化生物学的兴趣，并传播关于植物色素对人类健康重要性的认识。

This project will investigate whether evolution may be predictable at the genetic level. Phenotypic convergence, the appearance of similar forms in independent lineages, provides an opportunity for testing the predictability of genetic evolution. Similar phenotypes in different lineages are often due to similar changes at the genetic level. One possible explanation is that, among the possible mechanisms for producing a particular phenotype, some genetic changes are preferentially fixed during the course of evolution. This project will test the preferential fixation hypothesis by comparing the genetic basis of white flower coloration above and below the species level. The central hypothesis predicts that a wide array of mutations will be responsible for white-flowered mutants within pigmented species, but only a subset of these classes of mutations will be fixed during transitions from pigmented to white flowers at the species level. Using a group of species in the potato family, the PI will apply a combination of genetic, developmental, and biochemical approaches to test this prediction. The results will lead to a better understanding of the relationship between microevolutionary and macroevolutionary change. These studies will have important implications for manipulating and enhancing pigment content in horticultural varieties and crops. Plant pigments, including those targeted by this project, are strong antioxidants that contribute to the positive health benefits of a diet rich in fruits and vegetables. Thus, a better understanding of how genetic changes affect pigment biosynthesis adds to the potential for improving crop species. The project encompasses local outreach activities for K-12 students in order to promote interest in plant evolutionary biology and to spread awareness about the importance of plant pigments in human health.