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Abstract The contribution of phenotypically plastic traits to evolution depends on the degree of environmental influence on the target of selection (the phenotype) as well as the underlying genetic structure of the trait and plastic response. Likewise, maternal effects can help or hinder evolution through affects to the response to selection. The sacoglossan sea slugAlderia willowiexhibits intraspecific variation for developmental mode (= poecilogony) that is environmentally modulated with populations producing more yolk‐feeding (lecithotrophic) larvae during the summer, and more planktonic‐feeding (planktotrophic) larvae in the winter. I found significant family‐level variation in the reaction norms between 17 maternal families ofA. willowiwhen reared in a split‐brood design in low (16 ppt) versus high (32 ppt) salinity, conditions which mimic seasonal variation in salinity of natural populations. I documented a significant response to selection for lecithotrophic larvae in high and low salinity. The slope of the reaction norm was maintained following one generation of selection for lecithotrophy. When the maternal environment was controlled in the laboratory, I found significant maternal effects, which reduced the response to selection. These results suggest there is standing genetic variation for egg‐mass type inA. willowi,but the ability of selection to act on that variation may depend on the environment in which the phenotype is expressed in preceding generations.
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This content will become publicly available on February 1, 2026
Developmental reaction norms vary among families of lizards in response to multivariate nest environments
Developmental plasticity is the capacity of a single genotype to express multiple phenotypes in response to different early‐life environments. Such responses are defined by reaction norms, which may vary among individuals or populations. Variation in developmental reaction norms allows natural selection to operate on plasticity and is rarely examined in vertebrates. We quantified variation in embryonic developmental plasticity within and between populations using the brown anole lizard. We captured lizards from two islands in the Matanzas River (Florida, USA) and incubated their eggs under one of two multivariate treatments that mimicked the temperature, moisture and substrates of nest sites in either a shaded or open habitat. We measured hatchling morphology, performance, and physiology to quantify variation in family‐level reaction norms. We observed evidence of family‐level variation in reaction norms for morphology but not for performance or physiology, indicating an opportunity for natural selection to shape plasticity in hatchling body size. Overall, the results indicate that multiple abiotic conditions in natural nests combine to increase or reduce phenotypic variation, and that family‐level variation in reaction norms provides a potential for natural selection to shape plasticity.
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- Award ID(s):
- 1942145
- PAR ID:
- 10571765
- Publisher / Repository:
- Nordic Society Oikos
- Date Published:
- Journal Name:
- Oikos
- Volume:
- 2025
- Issue:
- 2
- ISSN:
- 0030-1299
- Page Range / eLocation ID:
- 2024: e10911
- Subject(s) / Keyword(s):
- Adaptation among-individual variation Anolis sagrei Developmental plasticity ecological development egg incubation thermal plasticity
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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