Sachs Joel L
Department of Biology, University of California, Riverside, CA 92521, USA.
Trends Ecol Evol. 2008 May;23(5):245-8. doi: 10.1016/j.tree.2008.02.003. Epub 2008 Apr 2.
Multicellular life has evolved many times, yet each origin requires free cells to integrate unselfishly into a higher-level individual. How can such transitions evolve? In a new paper, Herron and Michod investigate the recent origins of multicellularity in colonial algae. Their phylogenetic reconstructions provide a striking dissection of early steps, and altruistic traits are at the crux of it. Key evolutionary reversals are also revealed, where cellular selfishness might have thwarted multicellular integration.
多细胞生命已经进化了很多次，但每次起源都需要自由细胞无私地整合为一个更高层次的个体。这样的转变是如何进化的呢？在一篇新论文中，赫伦和米乔德研究了群体藻类中多细胞性的近期起源。他们的系统发育重建对早期步骤进行了引人注目的剖析，而利他性状是其中的关键。还揭示了关键的进化逆转，即细胞的自私可能阻碍了多细胞整合。
