Peto’s paradox and elephant TP53 retrogenes: cancer or reproduction?

In brief: Elephants have an expanded family of TP53 retrogenes that have been interpreted as an anti-cancer adaptation. This point of view suggests an alternative explanation and argues that reproduction is often sidelined in discussions of pleiotropic gene function. Abstract: Expansion of the elephant TP53 retrogene family has been proposed to contribute to cancer prevention in this large, long-lived species, consistent with Peto’s paradox. However, the P53 protein acts in several physiological contexts, and the exclusive focus on cancer exemplifies the marginalisation of reproduction in studies of pleiotropic gene function.