PS 80-136 - Accelerated reproduction is not an adaptive response to early adversity in wild baboons

Friday, August 16, 2019
Exhibit Hall, Kentucky International Convention Center
Chelsea Weibel1, Jenny Tung2,3, Susan C. Alberts2,3 and Elizabeth A. Archie1,2, (1)Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, (2)Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya, (3)Department of Biology, Duke University, Durham, NC
Background/Question/Methods

Harsh conditions in early life often lead to reduced lifespans. This reduced life expectancy has led several researchers to propose that individuals experiencing early life adversity should accelerate their life histories to maximize fitness, especially the timing and pace of reproduction. While various versions of this acceleration hypothesis have been proposed over the last 35 years, the adaptive benefit of reproductive acceleration under early adversity has never been shown. Here, we utilize the predictions of one of the most recent versions of this theory, the internal predictive adaptive response (iPAR) model, to test, for the first time, whether accelerating individual life history schedules in response to early adversity leads to higher lifetime reproductive success in a long-lived species. The specific predictions we test are: (i) early adversity leads to poor adult phenotypic quality, and (ii) accelerated reproduction is adaptive for individuals who experience early adversity and poor adult phenotypic quality. We test these predictions using four distinct sources of early adversity and three pace of life measures from 48 years of demographic data collection on the Amboseli baboon population.

Results/Conclusions

Previous work in this population found that early adversity leads to dramatically shorter lifespans. Nevertheless, we found that individuals who experienced early adversity did not accelerate their reproduction. Further, we found that while accelerated reproduction improves lifetime reproductive success in general, it is not a specific property of individuals that experienced early adversity or had short lifespans; for these individuals, our data suggest that accelerated reproduction may even be costly. Our results call into question the theory that accelerated reproduction is an adaptive response to early adversity, at least in long-lived animals like baboons.