Cohen Phoebe A, Riedman Leigh Anne
Williams College Department of Geosciences, Williamstown, MA, U.S.A.
Department of Earth Science, University of California Santa Barbara, Santa Barbara, CA, U.S.A.
Emerg Top Life Sci. 2018 Sep 28;2(2):173-180. doi: 10.1042/ETLS20170145.
Predation, and how organisms respond to it, is an important ecological interaction across the tree of life. Much of our understanding of predation focuses on modern metazoa. However, predation is equally important in single-celled eukaryotes (commonly referred to as protists). In the fossil record, we see evidence of protists preying on other protists beginning in the Tonian Period (1000-720 Ma). In addition, the first evidence of eukaryotic biomineralization and the appearance of multiple unmineralized but recalcitrant forms are also seen in the Tonian and Cryogenian (720-635 Ma), potentially indirect evidence of predation. This fossil evidence, coupled with molecular clock analyses, is coincident with multiple metrics that show an increase in the diversity of eukaryotic clades and fossil assemblages. Predation, thus, may have played a critical role in the diversification of eukaryotes and the evolution of protistan armor in the Neoproterozoic Era. Here, we review the current understanding of predation in the Tonian and Cryogenian oceans as viewed through the fossil record, and discuss how the rise of eukaryotic predation upon other eukaryotes (eukaryovory) may have played a role in major evolutionary transitions including the origins of biomineralization.
捕食以及生物体如何应对捕食，是生命之树上一种重要的生态相互作用。我们对捕食的大部分理解都集中在现代后生动物上。然而，捕食在单细胞真核生物（通常称为原生生物）中同样重要。在化石记录中，我们看到从托宁期（10亿至7.2亿年前）开始就有原生生物捕食其他原生生物的证据。此外，在托宁期和成冰纪（7.2亿至6.35亿年前）还发现了真核生物生物矿化的首个证据以及多种未矿化但难降解形式的出现，这可能是捕食的间接证据。这些化石证据与分子钟分析结果一致，多项指标显示真核生物类群和化石组合的多样性有所增加。因此，捕食可能在新元古代真核生物的多样化以及原生生物盔甲的进化过程中起到了关键作用。在此，我们通过化石记录回顾目前对托宁期和成冰纪海洋中捕食的认识，并讨论真核生物对其他真核生物的捕食（真核生物捕食）的兴起如何可能在包括生物矿化起源在内的重大进化转变中发挥作用。
