James W H
MRC Mammalian Development Unit, University College London, U.K.
J Theor Biol. 1989 Jul 10;139(1):59-67. doi: 10.1016/s0022-5193(89)80057-8.
I have previously suggested that parental levels of several hormones (gonadotrophin, oestrogen, testosterone) at the time of conception affect the sex of mammalian offspring (James, 1986, J. theor. Biol. 118, 427). In this note it is suggested that progesterone also has such an effect. Clutton-Brock & Iason (1986, Q. Rev. Biol. 61, 339) concluded that variation of sex ratio had been reasonably well established with a number of variables in a number of non-human mammalian species. In this note, discussion centres on the adequacy of my hypothesis to accommodate these and other data. The evidence now is strong that hormonal variation is associated with variation of sex ratio at birth in some mammalian species: in a few species (e.g. man and the vole) there is a strong presumption that the relationship is causal. However the same sort of cause apparently affects the sex ratio in opposite directions in different species: so it may be speculated that the same hormone has opposite effects on sex ratio in different species.
我之前曾提出，受孕时父母体内几种激素（促性腺激素、雌激素、睾酮）的水平会影响哺乳动物后代的性别（詹姆斯，1986年，《理论生物学杂志》第118卷，第427页）。在本笔记中，有人提出孕酮也有这样的作用。克拉顿-布罗克和艾森（1986年，《生物学季评》第61卷，第339页）得出结论，在许多非人类哺乳动物物种中，性别比例的变化已与一些变量合理地建立了联系。在本笔记中，讨论集中在我的假设是否足以解释这些及其他数据。现在有充分的证据表明，激素变化与某些哺乳动物物种出生时的性别比例变化有关：在少数物种（如人类和田鼠）中，有很强的推测认为这种关系是因果关系。然而，同样的原因显然在不同物种中对性别比例有相反的影响：因此可以推测，同一种激素在不同物种中对性别比例有相反的作用。
