Division of Biology, Imperial College London, Silwood Park Campus, Ascot, Berkshire, UK.
J Evol Biol. 2009 May;22(5):1024-35. doi: 10.1111/j.1420-9101.2009.01714.x.
Understanding why rates of morphological evolution vary is a major goal in evolutionary biology. Classical work suggests that body size, interspecific competition, geographic range size and specialization may all be important, and each may increase or decrease rates of evolution. Here, we investigate correlates of proportional evolutionary rates in phalangeriform possums, phyllostomid bats, platyrrhine monkeys and marmotine squirrels, using phylogenetic comparative methods. We find that the most important correlate is body size. Large species evolve the fastest in all four clades, and there is a nonlinear relationship in platyrrhines and phalangeriformes, with the slowest evolution in species of intermediate size. We also find significant increases in rate with high environmental temperature in phyllostomids, and low mass-specific metabolic rate in marmotine squirrels. The mechanisms underlying these correlations are uncertain and appear to be size specific. We conclude that there is significant variation in rates of evolution, but that its meaning is not yet clear.
理解形态进化率变化的原因是进化生物学的主要目标。经典研究表明，体型、种间竞争、地理范围大小和特化程度都可能很重要，而且每个因素都可能增加或降低进化率。在这里，我们使用系统发育比较方法研究了袋狸目负鼠、食虫目蝙蝠、阔鼻猴和地松鼠中比例进化率的相关因素。我们发现，最重要的相关因素是体型。在所有四个类群中，体型较大的物种进化最快，在阔鼻猴和袋狸目中存在非线性关系，中等体型的物种进化最慢。我们还发现食虫目蝙蝠的进化率与环境温度显著相关，地松鼠的代谢率与体重呈负相关。这些相关性的潜在机制尚不确定，而且似乎具有特异性。我们的结论是，进化率存在显著差异，但目前还不清楚其意义。
