Wootton J Timothy
Department of Zoology, NJ-15, University of Washington, Seattle, WA, 98195.
Evolution. 1987 Jul;41(4):732-749. doi: 10.1111/j.1558-5646.1987.tb05849.x.
I examined age at first reproduction of 547 mammalian species to determine the influence of diet and habitat on the evolution of life-history traits. Body mass correlated positively with age at first reproduction, explaining 56% of the variance. Habitat and trophic groups deviated significantly from the allometric curve in a pattern generally consistent with predictions from r/K selection theory and its modifications. However, mammalian orders also deviated significantly from the allometric curve, and different habitat and diet groups contained different ratios of mammalian orders. When the effects of orders were removed, residual deviations did not differ among ecological groups. Adjusting for ecological differences did not eliminate the differences between orders. These results suggest that body mass (or some correlated factor) and phylogeny strongly constrain age at first reproduction. Ecological factors appear to have little effect on the evolution of age at first reproduction. Apparent differences in weight-specific ages at first reproduction within habitats and trophic groups may be the result of ecological selection of order composition in the present, rather than ecologically driven evolution of life history in the past.
我研究了547种哺乳动物的首次繁殖年龄，以确定饮食和栖息地对生活史特征进化的影响。体重与首次繁殖年龄呈正相关，解释了56%的方差。栖息地和营养类群显著偏离了异速生长曲线，其模式总体上与r/K选择理论及其修正的预测一致。然而，哺乳动物目也显著偏离了异速生长曲线，不同的栖息地和饮食类群包含不同比例的哺乳动物目。当目效应被去除后，生态类群之间的残余偏差没有差异。调整生态差异并没有消除目之间的差异。这些结果表明，体重（或一些相关因素）和系统发育强烈限制首次繁殖年龄。生态因素似乎对首次繁殖年龄的进化影响很小。栖息地和营养类群内首次繁殖的体重特异性年龄的明显差异可能是目前目组成的生态选择的结果，而不是过去生活史的生态驱动进化。
