A change in climate causes rapid evolution of multiple life-history traits and their interactions in an annual plant
A change in climate causes rapid evolution of multiple life-history traits and their interactions in an annual plant
复制标题
DOI：
10.1111/j.1420-9101.2008.01566.x
复制
发表时间：
2008-09-01
影响因子：
2.1
通讯作者：
Weis, A. E.
中科院分区：
文献类型：
--
作者：
Franks, S. J.;Weis, A. E.
气候变化可能会刺激快速进化，潜在地改变一整套完整的生活史特征。我们研究了在加利福尼亚州南部最近5年干旱之前和之后收集的一年生植物白菜的多个生活史特征的进化变化。我们使用了一种直接的方法，通过比较祖先和后代来研究进化变化。从平均土壤水分水平不同的两个种群进行采集，由采集的种子繁殖的品系在温室中种植，并在模拟干旱(短生长季)或高降水(长生长季)的条件下进行实验。比较祖先和后代，我们发现干旱导致了许多生活史性状的变化，包括提前开花，开花持续时间更长，开花高峰期缩短，开花时序更倾斜。后代在开花时茎较细，叶节较少，表明干旱选择了开花较小、个体发育阶段较早的植株，而不是选择植株发育较快的植株。因此，没有证据表明开花时间的进化受到绝对的发育限制。共同主成分分析表明，短生长季处理与长生长季处理之间以及种群之间的性状协方差矩阵均存在显著差异。虽然祖先后代之间的协方差矩阵基本相似，但有证据表明性状之间的关系存在复杂的进化变化，这些变化取决于种群和处理。这些结果表明，充分了解全球变化对表型进化的影响，将需要理解气候条件的变化如何影响性状值和性状之间的关系结构。
Climate change is likely to spur rapid evolution, potentially altering integrated suites of life-history traits. We examined evolutionary change in multiple life-history traits of the annual plant Brassica rapa collected before and after a recent 5-year drought in southern California. We used a direct approach to examining evolutionary change by comparing ancestors and descendants. Collections were made from two populations varying in average soil moisture levels, and lines propagated from the collected seeds were grown in a greenhouse and experimentally subjected to conditions simulating either drought (short growing season) or high precipitation (long growing season) years. Comparing ancestors and descendants, we found that the drought caused many changes in life-history traits, including a shift to earlier flowering, longer duration of flowering, reduced peak flowering and greater skew of the flowering schedule. Descendants had thinner stems and fewer leaf nodes at the time of flowering than ancestors, indicating that the drought selected for plants that flowered at a smaller size and earlier ontogenetic stage rather than selecting for plants to develop more rapidly. Thus, there was not evidence for absolute developmental constraints to flowering time evolution. Common principal component analyses showed substantial differences in the matrix of trait covariances both between short and long growing season treatments and between populations. Although the covariances matrices were generally similar between ancestors and descendants, there was evidence for complex evolutionary changes in the relationships among the traits, and these changes depended on the population and treatment. These results show that a full appreciation of the impacts of global change on phenotypic evolution will entail an understanding of how changes in climatic conditions affect trait values and the structure of relationships among traits.