Huang Danwei, Goldberg Emma E, Roy Kaustuv
Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore; Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA 52242;
Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN 55108; and.
Proc Natl Acad Sci U S A. 2015 Apr 21;112(16):4909-14. doi: 10.1073/pnas.1409886112.
Anthropogenic impacts are endangering many long-lived species and lineages, possibly leading to a disproportionate loss of existing evolutionary history (EH) in the future. However, surprisingly little is known about the loss of EH during major extinctions in the geological past, and thus we do not know whether human impacts are pruning the tree of life in a manner that is unique in the history of life. A major impediment to comparing the loss of EH during past and current extinctions is the conceptual difference in how ages are estimated from paleontological data versus molecular phylogenies. In the former case the age of a taxon is its entire stratigraphic range, regardless of how many daughter taxa it may have produced; for the latter it is the time to the most recent common ancestor shared with another extant taxon. To explore this issue, we use simulations to understand how the loss of EH is manifested in the two data types. We also present empirical analyses of the marine bivalve clade Pectinidae (scallops) during a major Plio-Pleistocene extinction in California that involved a preferential loss of younger species. Overall, our results show that the conceptual difference in how ages are estimated from the stratigraphic record versus molecular phylogenies does not preclude comparisons of age selectivities of past and present extinctions. Such comparisons not only provide fundamental insights into the nature of the extinction process but should also help improve evolutionarily informed models of conservation prioritization.
人为影响正危及许多长寿物种和谱系，可能导致未来现有进化史（EH）出现不成比例的损失。然而，令人惊讶的是，对于地质历史上重大灭绝事件中进化史的损失，我们知之甚少，因此我们不知道人类影响是否正在以生命史上独一无二的方式修剪生命之树。比较过去和当前灭绝事件中进化史损失的一个主要障碍是，从古生物学数据与分子系统发育学估计年龄的概念差异。在前一种情况下，一个分类单元的年龄是其整个地层范围，无论它可能产生了多少子分类单元；对于后者，它是与另一个现存分类单元共享的最近共同祖先的时间。为了探讨这个问题，我们使用模拟来了解进化史的损失在这两种数据类型中是如何表现的。我们还对加利福尼亚州上新世 - 更新世大灭绝期间的海洋双壳类谱系扇贝科进行了实证分析，该灭绝事件涉及较年轻物种的优先损失。总体而言，我们的结果表明，从地层记录与分子系统发育学估计年龄的概念差异并不妨碍对过去和现在灭绝事件的年龄选择性进行比较。此类比较不仅能为灭绝过程的本质提供基本见解，还应有助于改进基于进化的保护优先级模型。
