The Adaptive Sex in Stressful Environments. (July 2019)

• Record Type: Journal Article
• Authors: Geffroy, Benjamin; Douhard, Mathieu
• Is Part Of: Trends in ecology & evolution. Volume 34:Number 7(2019)
• Page Start: 628
• Page End: 640
• Publication Date: 2019-07
• Subjects: sex determination -- sex ratio -- maternal effect -- adaptive response -- glucocorticoids; Ecology -- Periodicals; Evolution (Biology) -- Periodicals; 576.8
• DOI: 10.1016/j.tree.2019.02.012
• Languages: English
• ISSNs: 0169-5347

Abstract

Abstract : The impact of early stress on juvenile development has intrigued scientists for decades, but the adaptive significance of such effects remains an ongoing debate. This debate has largely ignored some characteristics of the offspring, such as their sex, despite strong evolutionary and demographic implications of sex-ratio variation. We review recent studies that examine associations between glucocorticoids (GCs), the main class of stress hormones, and offspring sex. Whereas exposure to GCs at around the time of sex determination in fish consistently produces males, the extent and direction of sex-ratio bias in response to stress vary in reptiles, birds, and mammals. We propose proximate and ultimate explanations for most of these trends. Highlights: Offspring sex ratios have been shown to correlate with environmental stressors and maternal stress in many vertebrate species. There is an adaptive advantage for parents to produce the sex that is more likely to survive and reproduce in a future hazardous environment. In the fastest life histories, there is more likely to be a close good match between the environment around sex determination and the future environment of the offspring. GCs are key messengers of environmental contexts that likely influence the sex-determination processes of various species. A combination of field and laboratory studies will be necessary to understand the extent to which stress influences offspring sex from conception to birth.