Code for 'Maternal age effects on offspring lifespan and reproduction vary within a species' by Liguori et al. 2024
Abstract: Across diverse taxa, offspring from older mothers have decreased lifespan and fitness. Little is known about whether such maternal age effects vary among genotypes for a given species, however, except for studies of a few arthropod species. To investigate the presence and degree of intraspecific variability in maternal age effects, we compared lifespan, reproductive schedule, and lifetime reproductive output of offspring produced by young, middle-aged, and old mothers in four strains of rotifers in the Brachionus plicatilis species complex. We found significant variability among strains in the magnitude and direction of maternal age effects on offspring life history traits. In one strain, offspring of young mothers lived 20% longer than offspring of old mothers, whereas there were no significant effects of maternal age on lifespan for other strains. Depending on strain, advanced maternal age had positive effects, negative effects, or no effect on lifetime reproductive output. Across strains, older mothers produced offspring that had higher maximum daily reproduction early in life. Effects of maternal age on offspring vital rates could not be explained by changes in trade-offs between lifespan and reproduction. Investigating intraspecific variability is critical for understanding the ubiquity of maternal age effects and their role in the evolution of life history and aging.