Human digit ratios depend on birth order and sex of older siblings and predict maternal fecundity
Human digit ratios depend on birth order and sex of older siblings and predict maternal fecundity
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DOI：
10.1007/s00265-005-0137-1
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发表时间：
2006-05-01
影响因子：
2.3
通讯作者：
Romano, M
中科院分区：
文献类型：
--
作者：
Saino, N;Leoni, B;Romano, M
在男性中，第二与第四手指的长度比（2D：4D）较小，而第四手指的长度相对于身高（4D：H）大于女性。2D：4D和4D：H的性内和性间变异可能取决于胎儿雄激素和雌激素环境的变化。由于母体生理随产次而变化，并且受任一性别妊娠的不同影响，后代2D：4D和4D：H可能会根据性别和年长兄弟姐妹的数量而变化，并可能预测随后的母体表现。我们分析了高加索大学生的2D：4D和4D：H。雄性2D：4D比雌性小，4D：H比雌性大，但2D：H不存在性二型。在男性中，长度比不随出生顺序而变化。随着年长兄弟姐妹中男性比例的增加，2D：4D变得更加男性化，随着年长姐妹篇数量的增加，2D：4D和4D：H变得更加女性化。在女性中，长度比例不随姐妹篇或哥哥的数量而变化。2D：4D也与胎次无关，但4D：H随着胎次的增加而变得更男性化。在女性中，残余母体生育力（参与者之后的母体后代数量）随着4D：H变得更加男性化而下降。这些发现与以前的研究结果部分一致，并表明母体的生育力与长度比，因此可能与年龄较大的后代的胎儿激素环境。因此，2D：4D和4D：H可能代表了在机制和进化水平上研究胎儿环境、后代表型和母体生活史之间关系的有力工具。
In men, the length ratio of the second to fourth finger (2D:4D) is smaller, while the length of the fourth finger relative to body height (4D:H) is larger than in women. Inter- and intrasexual variations in 2D:4D and 4D:H may depend on variation in fetal androgen and oestrogen environment. As maternal physiology varies with parity and is differentially affected by gestation of either sex, offspring 2D:4D and 4D:H may change according to sex and number of older siblings and may predict subsequent maternal performance. We analysed 2D:4D and 4D:H in Caucasian university students. 2D:4D was smaller and 4D:H was larger in males than in females, but no sexual dimorphism existed in 2D:H. In males, length ratios did not vary with birth order. 2D:4D became more masculine with increasing proportion of males among older siblings, and 2D:4D and 4D:H became more feminine as the number of older sisters increased. In females, length ratios did not vary with the number of older sisters or brothers. 2D:4D was also not related to birth order, but 4D:H became more masculine with birth order. In females, residual maternal fecundity (number of maternal offspring after the participant) decreased as 4D:H became more masculine. These findings are partly consistent with those from previous studies and suggest that maternal fecundity co-varies with length ratios and thus possibly fetal hormone environment of older offspring. 2D:4D and 4D:H may therefore represent powerful tools to investigate the relationships between fetal environment, offspring phenotype and maternal life history at mechanistic and evolutionary levels.