Offspring reproductive success is a greater determinant of human genetic contributions than offspring number or survival

Description

Fitness is a fundamental concept in evolutionary biology. Fitness will ultimately be determined after many generations, as it is defined as the long-term genetic contributions individuals make to the future population. However, the relative importance of an individual’s own life history versus their offspring’s in determining genetic contributions is unclear. Here, we investigate and quantify this using individual life-history data from a pedigreed population of humans from Switzerland spanning four centuries. Specifically, we examine the relative importance of the lifespan and reproduction of an individual, and the survival and reproduction of their offspring in determining the long-term genetic contributions of 2,623 individuals using generalised linear mixed models. We find that the reproductive success of offspring is a far greater determinant of individual genetic contributions (57% of variance explained) than number of offspring (only 29%). Additionally, the number of surviving offspring to adulthood explained the same level of variance as number of offspring born, showing that offspring mating and reproductive success (and not survival) is the key determinant of long-term genetic contributions. In contrast, lifespan is a very poor determinant of genetic contributions with only 13% of variance explained. Finally, we find no evidence for a quality-quantity trade-off in offspring reproduction, showing that it is unlikely to explain these results. These findings have implications for measuring natural selection in humans and other species, while demonstrating the use of human genealogical datasets for studying evolutionary processes.

Periode	29-jul.-2022
Evenementstitel	International Society for Behavioral Ecology Congress 2022
Evenementstype	Conference
Conferentienummer	18
Locatie	Stockholm, SwedenToon op kaart
Mate van erkenning	International