Menopause, the complete cessation of menstrual cycles, apparently is a detrimental trait, yet all women experience it. Numerous theories have been proposed to explain the origin of menopause, but none has been satisfactory. In 2013, Morton et al. proposed a mate choice hypothesis to explain menopause and, using a computational model, showed how a bias in mating (i.e., older men preferring younger women) could have allowed such an otherwise detrimental trait to evolve neutrally through accumulation of female fertility-reducing mutations. To investigate whether biased mating could affect fecundity and fertility in a real system, two experimental populations were established using Drosophila melanogaster. Older males were mated with younger females and vice versa. Information was obtained, including data on fecundity, fertility, ovariole and matured egg chambers, and lifespan, for experimental, age-restricted-mating and control populations. A negative effect on the fecundity and fertility of the younger-mating sex was observed in restricted-mating compared to control populations. Age-restricted mating had no effect on longevity. Menopause could evolve according to the mate choice hypothesis. / Thesis / Master of Science (MSc) / All animals are expected to remain fertile until they die. Menopause is an enigma and an unsolved problem in evolutionary biology. Numerous theories have been proposed to explain menopause, but there is no clear understanding of how this fertility reducing trait evolved in the human population. It has been proposed that biased mate choice i.e., preference for younger females can lead to accumulation of fertility-reducing mutations and the evolution of menopause. In this study, mate choice theory was tested using altered (biased) mating schemes with Drosophila melanogaster and the results support the mate choice theory of menopause.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/24784 |
| Date | January 2019 |
| Creators | Purohith, Divya |
| Contributors | Singh, Rama, Biology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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