Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota 55108, USA.
Am Nat. 2011 Sep;178(3):355-71. doi: 10.1086/661245.
Competition theory predicts that multispecies coexistence requires that species have traits that fall on the same interspecific trade-off surface. Fossil records for mollusks, mammals, trees, and other taxa show that with rare exception, ecologically similar species have coexisted for a million years or more after interchange between formerly isolated realms. This coexistence suggests the possibility, termed the universal trade-off hypothesis, that ecologically similar species of different realms have been bound to the same interspecific trade-off surface despite millions of years of independent evolution. Such persistence fails to support the biogeographic superiority hypothesis, which posits that genetic drift, recombination, mutation, and selection would cause taxa of one realm to gain superiority over those of another realm during long periods of isolation. Analysis of the lengths of time that species have persisted once in contact suggests that the trade-off surfaces of realms differed by <0.1% at the time of interchange. This implies that macroevolutionary patterns of differentiation and speciation within and between realms were more likely the movement of traits on a common trade-off surface rather than directional selection achieved without compensatory trade-offs and costs. The existence of transrealm trade-offs, should further work support this possibility, has deep implications for ecology and evolution.
竞争理论预测，多物种共存需要物种具有落在相同种间权衡表面上的特征。来自软体动物、哺乳动物、树木和其他分类群的化石记录表明，除了极少数例外，在以前孤立的领域之间相互交换后，生态相似的物种已经共存了一百万年或更长时间。这种共存表明了一种可能性，即所谓的普遍权衡假说，即尽管经过了数百万年的独立进化，但不同领域的生态相似物种仍然受到相同种间权衡表面的限制。这种持续存在不符合生物地理优势假说，该假说认为，在长时间的隔离过程中，遗传漂变、重组、突变和选择会导致一个领域的分类群相对于另一个领域的分类群获得优势。对物种一旦接触后持续存在的时间进行分析表明，在相互交换时，领域之间的权衡表面差异<0.1%。这意味着领域内和领域间的分化和物种形成的宏观进化模式更可能是在共同权衡表面上的特征移动，而不是在没有补偿性权衡和成本的情况下实现的定向选择。如果进一步的工作支持这种可能性，那么跨领域的权衡的存在将对生态学和进化产生深远的影响。
