Publication Date



The paradox of sex is one of biology’s great evolutionary questions, particularly in those species that are fully capable of sexual and asexual reproduction. To quantify how fitness varies between these two modes of reproduction, we explored lifetime fecundity in Megaphasma dentricus, the giant walking stick of North America. For the first 20 days of egg laying, there were no fecundity differences between mated and unmated females with respect to egg number or egg weight; all females laid a total of ~50 eggs and each egg weighed about 0.02g. For days 21-50 (the last 30 days of egg laying), unmated females laid significantly fewer (but not lighter) eggs than sexually reproducing females. Overall, lifetime fecundity in unmated females was about 5-10% less than mated females. Myriad factors remain unexplored in this species, including the ploidy of sexually and asexually produced eggs, the effects of parasites or other considerations of co-evolution (e.g., the Red Queen Hypothesis), and the accumulation of deleterious mutations (e.g., Muller’s Ratchet).


Sexual behavior in animals; Stick insects

Publication Information

Texas Journal of Science, 2016, Volume 65, Issue 4, 3-13.

© 2016 Texas Academy of Science

Archived version is the final published version.



Document Type

Journal Article

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Biology Commons