Pettay Jenni E, Kruuk Loeske E B, Jokela Jukka, Lummaa Virpi
Section of Ecology, Department of Biology, University of Turku, FIN-20014, Turku, Finland.
Proc Natl Acad Sci U S A. 2005 Feb 22;102(8):2838-43. doi: 10.1073/pnas.0406709102. Epub 2005 Feb 8.
An increasing number of studies have documented phenotypic selection on life-history traits in human populations, but less is known of the heritability and genetic constraints that mediate the response to selection on life-history traits in humans. We collected pedigree data for four generations of preindustrial (1745-1900) Finns who lived in premodern fertility and mortality conditions, and by using a restricted maximum-likelihood animal-model framework, we estimated the heritability of and genetic correlations between a suite of life-history traits and two alternative measures of fitness. First, we demonstrate high heritability of key life-history traits (fecundity, interbirth interval, age at last reproduction, and adult longevity) and measures of fitness (individual lambda and lifetime reproductive success) for females but not for males. This sex difference may have arisen because most of the measured traits are under physiological control of the female, such that a male's fitness in monogamous societies may depend mainly on the reproductive quality of his spouse. We found strong positive genetic correlations between female age at first reproduction and longevity, and between interbirth intervals and longevity, suggesting reduced life spans in females who either started to breed relatively early or who then bred frequently. Our results suggest that key female life-history traits in this premodern human population had high heritability and may have responded to natural selection. However genetic constraints between longevity and reproductive life-history traits may have constrained the evolution of life history and facilitated the maintenance of additive genetic variance in key life-history traits.
越来越多的研究记录了人类群体中对生活史特征的表型选择，但对于介导人类对生活史特征选择反应的遗传力和遗传限制了解较少。我们收集了生活在近代前生育和死亡条件下的四代工业化前（1745 - 1900年）芬兰人的谱系数据，并使用受限最大似然动物模型框架，估计了一系列生活史特征与两种替代适合度指标之间的遗传力和遗传相关性。首先，我们证明了关键生活史特征（繁殖力、生育间隔、最后一次繁殖年龄和成年寿命）以及适合度指标（个体λ和终生繁殖成功率）在女性中具有高遗传力，而在男性中则不然。这种性别差异可能是因为大多数测量的特征受女性生理控制，以至于在一夫一妻制社会中男性的适合度可能主要取决于其配偶的生殖质量。我们发现女性首次繁殖年龄与寿命之间以及生育间隔与寿命之间存在很强的正遗传相关性，这表明在相对较早开始繁殖或随后频繁繁殖的女性中寿命较短。我们的结果表明，在这个近代前人类群体中，关键的女性生活史特征具有高遗传力，并且可能对自然选择做出了反应。然而，寿命与生殖生活史特征之间的遗传限制可能限制了生活史的进化，并促进了关键生活史特征中加性遗传方差的维持。
