DISSERTATION RESEARCH: The Evolution of Late-Life Fecundity

这一提议的目的是用繁殖力来检验关于晚年生活的一般理论——包括进化的和非进化的。到目前为止，根据进化理论，生育能力在生命后期趋于稳定并逐渐退化。另一种非进化的假说无法令人满意地解释这些结果，因为晚年繁殖力的停滞不是由男性性功能减退、营养影响或死亡率停滞引起的。该实验将以黑腹果蝇为研究对象，专门测试晚年的异质性和拮抗多效性理论。生殖力的异质性将通过在一个大队列中测量终生个体生殖力来检验，并比较存活到生殖力平台期的雌性与未存活到生殖力平台期的雌性的生殖力模式。通过25代早期繁殖的选择，测试了晚年繁殖力和早期适应性之间的拮抗多效性，然后比较了早期繁殖组和原始晚期繁殖组之间的晚年繁殖力。

The objective of this proposal is to test general theories of late life - both evolutionary andnon-evolutionary - using fecundity. Thus far, fecundity has been shown to plateau late in life andevolve according to evolutionary theory. Alternative non-evolutionary hypotheses have not beenable to satisfactorily explain these results, as late-life fecundity plateaus do not arise fromdiminished male sexual function, nutritional effects, or mortality-rate plateaus.The proposed experiments will specifically test the heterogeneity and antagonisticpleiotropy theories of late life, using Drosophila melanogaster. Heterogeneity in fecundity willbe tested by measuring lifetime individual fecundity within a large cohort and comparingfecundity patterns of females that survive to the fecundity plateau with those that do not.Antagonistic pleiotropy between late-life fecundity and early fitness will be tested using 25generations of selection for earlier reproduction, followed by a comparison of late-life fecunditybetween the early-reproducing cohorts and the original later-reproducing cohorts.