Dimensions US-South Africa: Convergent evolution across time and space: Evolutionary diversity and contemporary adaptation in New and Old World lizards

自然选择，即具有不同特征的个体的差异生存和繁殖，是推动进化变化的主要过程。自然选择的一个标志是趋同进化：当处于同一环境中的不同物种的特征以相似的方式进化时。虽然趋同一度被认为是罕见的，但最近的研究表明，趋同发生得很普遍。然而，一个悬而未决的问题是，与远亲相比，近亲物种和种群是否更有可能在物理特征和基因方面趋同。自然史和基因组成的相似性可能会使近亲以类似的方式适应类似的环境。此外，当代适应人类活动造成的环境变化的情况越来越普遍。目前还不知道物种是否以适应环境自然变化的方式适应了生物遗传诱导的选择压力。这是一个重要的问题，因为面对环境变化，物种的生存可能取决于对新条件的不断适应。自然资源保护主义科学家对如何使进化适应更有可能产生兴趣。从这项研究中得出的关于适应的预测可能有助于指导行动，以最大限度地发挥种群的进化潜力。学生将接受国际科学研究方面的培训，一些外联活动将使公众更好地了解科学问题，这项研究将通过关注两组蜥蜴，加勒比阿诺利斯蜥蜴和南非变色龙来解决这些问题，并研究在多个层面上发生趋同的程度：在这些进化分支中的每一个分支中，以及在适应人类改变的环境的现代种群中，数百万年来的进化分歧将蜥蜴群体分开。这些问题将通过检查解剖学特征（例如腿长和身体大小）和研究不同蜥蜴群体之间的遗传差异来研究。此外，跨种群和物种的比较将有助于确定可能导致观察到的解剖学差异的候选基因。新的基因编辑方法将用于直接测试这些基因变化是否真的产生了预测的解剖学变化。这些研究将在理解自然选择在塑造适应未来环境变化方面的局限性方面发挥重要作用。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Natural selection, the differential survival and reproduction of individuals possessing different traits, is a major process driving evolutionary change. One sign of natural selection is convergent evolution: when traits in different species that occupy the same environment evolve in a similar matter. Although convergence was once assumed to be rare, recent research demonstrates that convergence occurs quite commonly. An outstanding question, however, is whether closely related species and populations are more likely to converge, both in their physical characteristics and in their genes, than more distant relatives. Similarities in natural history and genetic makeup might predispose close relatives to adapt in similar ways to similar circumstances. Moreover, contemporary adaptation to the changed environmental circumstances resulting from human actions is increasingly common. It is not known whether species are adapting to anthropogenically induced selective pressures in the same way as they have adapted to natural changes in the environment. This is an important question because species' survival in the face of environmental change may depend on evolving adaptations to new conditions. Conservationist scientists are gaining interest in how to make evolutionary adaptation more likely. The predictions about adaptation that will result from this research may be useful in guiding actions to maximize that evolutionary potential of populations. Students will be trained in international scientific research, and several outreach activities will engage the general public in better understanding of scientific issues.This study will address these questions by focusing on two groups of lizard, Caribbean Anolis lizards and South African chameleons, and examining the degree to which convergence occurs at multiple levels: between lizard groups separated by millions of years of evolutionary divergence, within each of these clades, and among modern-day populations adapting to human-altered environments. These questions will be investigated both by examining anatomical characteristics, for example leg length and body size, and by studying genetic differences among diverse groups of lizards. In addition, comparisons across populations and species will help identify candidate genes that may be responsible for the observed anatomical differences. New gene editing methods will be used to directly test whether these genetic changes actually produce the predicted anatomical changes. These studies will play an important role in understanding the limits of natural selection in shaping adaptation to future environmental change.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.