The genetics of convergent evolution: insights from plant photosynthesis

First author: Karolina Heyduk; Affiliations: Yale University (耶鲁大学): New Haven, USA

Corresponding author: Karolina Heyduk

The tree of life is resplendent with examples of convergent evolution, whereby distinct species evolve the same trait independently. Many highly convergent adaptations are also complex, which makes their repeated emergence surprising. In plants, the evolutionary history of two carbon concentrating mechanisms (CCMs) — C4 and crassulacean acid metabolism (CAM) photosynthesis — presents such a paradox. Both of these modifications of ancestral C3 photosynthesis require the integration of multiple anatomical and biochemical components, yet together they have evolved more than one hundred times. The presence of CCM enzymes in all plants suggests that a rudimentary CCM might emerge via relatively few genetic changes in potentiated lineages. Here, we propose that many of the complexities often associated with C4 and CAM photosynthesis may have evolved during a post-emergence optimization phase. The ongoing development of new model clades for young, emerging CCMs is enabling the comparative studies needed to test these ideas.

生命之树上存在一些趋同演化的案例，即不同的物种独立演化出相同的性状。许多高度趋同适应同样也很复杂，所以当他们重复出现时就显示很出乎意料。在植物中，两种碳浓缩机制C4和景天酸代谢CAM光合的演化历史正是这样的一个典型的案例。这两种碳浓缩机制都源自于对古老的C3途径的修改，需要整合多个结构和生化上的组份，同时演化超过数百次最终才形成了这样的结果。在所有植物中都存在CCM酶，说明可能最初的时候，通过少量的遗传改变形成了一个基础版的CCM。本文中，作者提出C4和CAM光合相关的复杂性组份可能是在形成后的优化阶段进行的演化。对于现在相对比较年轻、正在形成中的CCM的建模将有助于测试一些有关C4和CAM光合演化的基础假设。

通讯：Karolina Heyduk (https://eeb.yale.edu/people/postdoctoral-and-research-appointments/karolina-heyduk)

个人简介：2018年-至今，耶鲁大学，博士后。

doi: https://doi.org/10.1038/s41477-019-0437-5

Journal: Nature Reviews Genetics

Published date: March 18, 2019