EAGER: Investigating the Evolutionary and Environmental Bases of Twinning in Human Populations

在这个EAGER项目中，研究人员将研究人类中双胞胎的发生率，重点是高孪生率。异卵双生率在不同的人群中有所不同，这种差异和双胞胎的潜在适应优势还没有完全了解。这些研究人员和其他人以前的研究表明，遗传和环境因素都参与其中。该项目将收集关于一个具有极高孪生率的人口中孪生的规模和时间的初步信息，这将为随后的研究项目提供基础，以了解现代人类多胞胎的文化，生物，进化和环境背景。该项目还支持国际研究合作，并可能导致为生育研究提供信息的发现。 自发双卵双生（DZ）发生在两个卵母细胞的释放和受精。双卵双生的遗传因素早已被认识到，可能包括与卵泡群大小和多次着床相关的基因，但没有明确的遗传模式已被确定。吸烟等环境因素也可能影响双胞胎的比率。研究人员将收集印度南部一个村庄双胞胎发生的信息，重建该村庄何时开始有超出其他印度人口正常范围的双胞胎频率，并开始探索微进化过程和环境化学暴露的潜在影响。

In this EAGER project, the investigators will study the occurrence of twins in human populations, with a focus on high twinning rates. Fraternal twinning rates vary across populations, and this variation and the potential adaptive advantages of having twins are not fully understood. Previous research by these investigators and others suggest that both genetic and environmental factors are involved. This project will collect initial information on the scale and timing of twinning in one population with an extremely high twinning rate, which will provide a foundation for subsequent research projects to understand the cultural, biological, evolutionary, and environmental contexts of multiple births in modern humans. The project also supports international research collaborations and may lead to findings that inform fertility research. Spontaneous dizygotic (DZ) twinning occurs with the release and fertilization of two oocytes. A genetic component to dizygotic twinning has long been recognized, potentially including genes related to follicle cohort size and multiple implantation, but no clear inheritance pattern has been identified. Environmental factors such as smoking may also influence twinning rates. The investigators will collect information on twin occurrence in a village in southern India, to reconstruct when the village started to have twin frequencies that are out of the normal range of other Indian populations, and to begin to explore the potential effects of microevolutionary processes and environmental chemical exposure.