Being stuck in an evolutionary mismatch decreases fertility rates. This phenomenon is well documented in zoology:

"Captive-born animals have a 42% decreased odds of reproductive success in captivity compared to their wild-born counterparts" (1)

"Zoo population managers can improve the reproduction and health of captive species by addressing the evolutionary mismatch between the environment that their species are adapted for, and the captive zoo environment in which they currently exist" (2)

1. A meta-analysis of birth-origin effects on reproduction in diverse captive environments
https://pmc.ncbi.nlm.nih.gov/articles/PMC5849764/
2. Integrating evolution in the management of captive zoo populations
https://pmc.ncbi.nlm.nih.gov/articles/PMC4430766/

#fertility