Quantitative genetics of costly neonatal sexual size dimorphism in squirrel monkeys (Saimiri boliviensis) |
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Authors: | G E Blomquist L E Williams |
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Institution: | 1. Department of Anthropology, University of Missouri, , Columbia, MO, USA;2. Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, , Bastrop, TX, USA |
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Abstract: | Offspring size is often an intimate link between the fitness of parents and offspring. Among mammals, neonate mass is also related to adult levels of dimorphism and intrasexual competitive mating. We describe the sex‐specific genetic architecture of neonate mass in captive squirrel monkeys (Saimiri boliviensis), a small Neotropical primate. Best fitting quantitative genetic models show strong maternal genetic effects with little difference between sexes offering limited opportunity for neonatal dimorphism to respond to observed or hypothetical selection. Heritabilities that are approximately zero also imply it is unlikely that neonatal dimorphism can evolve as a correlated response to selection on adult size. However, male mass is also more dependent on maternal condition (age and parity) making dimorphism plastic. Finally, we hypothesize that large maternal genetic effects reflect income breeding and tightly synchronized seasonal reproduction in squirrel monkeys, both of which require strong maternal control of offspring growth and timing of birth. |
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Keywords: | animal model birth weight maternal effects phenotypic selection quantitative genetics sexual dimorphism |
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