How To Predict The Ratio Of Males To Females In Wild Animals

Plants and Animals





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Green lizards (Lacerta viridis) have ZW genetic sex determination systems, even though many other reptiles exhibit XY sex determination. András Liker

In the wild, some species tend to have more males than females, while some extreme populations might be composed of adult females exclusively. According to new findings published in Nature last week, the proportion of males to females – called the adult sex ratio – in many animal populations is based on the sex chromosomes. And that ratio can be predicted too.