Madrigal L
Department of Anthropology, University of South Florida, Tampa 33620, USA.
Hum Biol. 1995 Oct;67(5):779-87.
The reproductive performance of mothers of twins is of interest from an evolutionary perspective. Because mothers of twins have the potential of leaving a greater number of offspring, they could be favored by natural selection. At the same time, twin pregnancies are known to be associated with higher pre- and postnatal mortality. Thus mothers of twins at least have potentially higher fertility, a potential that may be hampered by greater mortality of twins. Here, I examine the completed fertility of 149 females, 50 years of age and older, from Limon, Costa Rica. In particular, the number of surviving children of mothers of twins and mothers of singletons at the time of the interview is compared. In this sample mothers of twins have a higher fertility at the end of their reproductive career. Their selection coefficient indicates that natural selection favors them through differential fertility.
从进化的角度来看，双胞胎母亲的生殖表现备受关注。由于双胞胎母亲有可能留下更多的后代，她们可能会受到自然选择的青睐。同时，众所周知，双胎妊娠与更高的产前和产后死亡率相关。因此，双胞胎母亲至少有潜在的更高生育率，而这种潜力可能会因双胞胎更高的死亡率而受到阻碍。在这里，我研究了来自哥斯达黎加利蒙的149名50岁及以上女性的终生生育率。特别是，比较了访谈时双胞胎母亲和单胞胎母亲的存活子女数量。在这个样本中，双胞胎母亲在其生殖生涯结束时具有更高的生育率。她们的选择系数表明，自然选择通过差异生育率对她们有利。
