Self-fertile, WT hermaphrodites generated 330 ± 40 self-progeny and displayed a reproductive span of 4.6 ± 0.9 days before reproduction ceased due to sperm depletion.
Seed mass may serve as a surrogate for a number of traits important to the population biology of species, such as dispersal ability [33], persistence in the soil [34], time to first reproduction, plant life span and reproductive lifespan [35], seedling survival [36], and number of seeds produced annually per plant [16], [35].
In this population, the phenotypic selection gradients were opposite in direction between the sexes for first and last reproduction, and reproductive life span, but these traits also showed positive, rather than negative, genetic correlations between the sexes, with regard to fitness (Bolund et al. 2013).
These organisms typically have a relatively delayed onset of reproduction, long life span, and consequent large body size, all features of hypermorphosis.
Men may also have, evolutionarily speaking, genetically prioritized reproduction over life span.
A multi-target vaccine, combining different single-target vaccines acting on different biological functions and life stages of the parasite, e.g. susceptibility to larva migration, reproduction and life span, would prove the most effective option, especially if none of the single-target vaccines are highly efficacious, and would prove more robust against antigenic drift [34].
Consistent with this idea, several studies have suggested that there may exist a trade-off between reproduction and life span.
The results inform the interpretation of experiments involving mifepristone, and implicate steroid hormone signaling in regulating the trade-off between reproduction and life span.
Moreover, the results implicate steroid hormone signaling and X-chromosome gene expression in regulating the trade-off between reproduction and life span caused by mating in female Drosophila.
These results are also consistent with studies of reproduction and life span in other species, such as ants (Schrempf et al. 2005), fish (Reznick et al. 2004), and birds (McCleery et al. 2008).
