Early Life Stress Strengthens Trait Covariance: A Plastic Response That Results in Reduced Flexibility.

In this study, we examined within- and among-trait associations for morphological and physiological traits in zebra finches (Taeniopygia guttata) exposed to corticosterone (CORT) during the nestling and fledging stages as well as in control birds. Birds exposed to CORT exhibited stronger within-trait correlations over time and stronger associations among traits. We found preliminary evidence that birds that died before the median age of death had stronger within- and among-trait correlations independent of treatment, and among CORT-treated birds, smaller birds were more likely to survive beyond the median age than larger birds. These findings suggest that stress hormone exposure in early life can result in reduced developmental flexibility, with potential fitness ramifications, and that these costs may be greater for larger offspring. Furthermore, our results provide experimental evidence for pleiotropic effects of hormones during development through altered patterns of phenotypic correlation.
PMID: 30332583 [PubMed - in process]

Source: The American Naturalist - October 18, 2018 Category: Biology Authors: Merrill L, Grindstaff JL Tags: Am Nat Source Type: research