The second in a series from the blog Gender and Sexuality in Nature, a 2016 UC Davis course organized by UM EEB alumnus Ash Zemenick (UM EEB B.S. 2011, Ph.D. UC Davis 2017) and Jacob Moore (B.S. University of Washington 2009, Ph.D. UC Davis 2017).
Discussion overview:
This week’s meeting focused on asexuality. Last week we defined asexuality, for the purposes of this seminar, as reproduction by an all-female (single sex) species that does not require fertilization by sperm. This week, we delved into the life cycles of several organisms that rely on asexuality for some or all of their reproduction.
Why has asexuality not completely taken over?
To start, we revisited on an idea from last week: the cost of producing males. Jay mentioned that this idea was specific to populations in which males do not actively promote the fitness/survival of offspring (i.e. in which males do not contribute to parental care). In this context, males provide genetic material, but nothing more. Consequently, sexual reproduction consumes time and energy (say, in finding a mate) without a lot of return benefit to females or offspring, and so keeping males in the population is “costly” in comparison to asexual reproduction. We wondered if males getting eaten post-mating (for organisms for which that occurs) counted as a sufficient contribution for negating that “cost”; our jury is still out!