Increased longevity evolves from grandmothering
Increased longevity evolves from grandmothering
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DOI：
10.1098/rspb.2012.1751
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发表时间：
2012-12-22
影响因子：
4.7
通讯作者：
Hawkes, Kristen
中科院分区：
文献类型：
--
作者：
Kim, Peter S.;Coxworth, James E.;Hawkes, Kristen
在我们的血统中，当祖先的祖母通过提供孙子孙女来补贴女儿的生育能力时，绝经后的寿命可能已经进化了，但直到现在，这种口头假设还缺乏数学支持。在这里，我们提出了一个正式的模拟，在这个模拟中，由于祖母效应，与现代黑猩猩相似的寿命延长到了现代人类的范围。长寿提高了活到生育年龄的几率，但却受到了男女成本不同的反对。我们祖母的假设是限制性的。只有自己不再生育的女性才有资格，女性的生育能力可以延长到45岁。最初，符合条件的祖母很少，影响很小。祖母一次只能抚养一个被抚养人，不会有选择地照顾女儿的后代。它们必须带走仍依赖母亲的最年长的幼崽；2岁以下的婴儿没有资格获得补贴。我们的模型不包括关于大脑、学习或结对的假设。仅祖母效应就足以使人类寿命在不到6万年的时间里翻一番。
Postmenopausal longevity may have evolved in our lineage when ancestral grandmothers subsidized their daughters' fertility by provisioning grandchildren, but the verbal hypothesis has lacked mathematical support until now. Here, we present a formal simulation in which life spans similar to those of modern chimpanzees lengthen into the modern human range as a consequence of grandmother effects. Greater longevity raises the chance of living through the fertile years but is opposed by costs that differ for the sexes. Our grandmother assumptions are restrictive. Only females who are no longer fertile themselves are eligible, and female fertility extends to age 45 years. Initially, there are very few eligible grandmothers and effects are small. Grandmothers can support only one dependent at a time and do not care selectively for their daughters' offspring. They must take the oldest juveniles still relying on mothers; and infants under the age of 2 years are never eligible for subsidy. Our model includes no assumptions about brains, learning or pair bonds. Grandmother effects alone are sufficient to propel the doubling of life spans in less than sixty thousand years.