Developmental plasticity affects sexual size dimorphism in an anole lizard
Developmental plasticity affects sexual size dimorphism in an anole lizard
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DOI：
10.1111/1365-2435.12468
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发表时间：
2016-02-01
影响因子：
5.2
通讯作者：
Smith, Thomas B.
中科院分区：
文献类型：
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作者：
Bonneaud, Camille;Marnocha, Erin;Smith, Thomas B.
虽然发育可塑性在实验室研究中被证明有助于性大小二型性(SSD)，但它在野生脊椎动物种群SSD变异中的作用尚不清楚。在这里，我们使用野外研究和实验室实验来表明，资源的可获得性影响巴哈马岛上萨格里蜥蜴种群的SSD程度。食物生物量的总量可以解释巴哈马六个岛屿上雄性个体大小的差异，但不能解释雌性个体大小的差异，这导致了SSD的显著差异。对一个圈养种群的实验室实验证实，SSD的变化是通过猎物生物量对雄性发育可塑性的影响来调节的，而不是雌性。事实上，在高饮食处理下，成年雄性比在限制饮食下生长得更快，体型也更大，而成年雌性在两种情况下都保持着相似的体型。我们的结果表明，可获得的食物的数量可以影响脊椎动物物种内身体大小的两性差异。如果通过减少性别之间的竞争，允许个体利用不同栖息地提供的不同水平的食物机会，特定性别的发育可塑性可能会受到青睐。因此，对食物可获得性的可塑性可能在萨格雷夜蛾入侵成功中发挥了作用。这项研究加深了我们对资源可获得性对爬行动物SSD形成的影响的理解，并进一步支持了条件依赖假说，根据该假说，较大的性别应该在对环境条件的反应中表现出更大的可塑性。
While developmental plasticity has been shown to contribute to sexual size dimorphism (SSD) in laboratory studies, its role in shaping SSD variation in wild vertebrate populations is unclear. Here we use a field study and a laboratory experiment to show that resource availability influences the degree of SSD among insular populations of Anolis sagrei lizards in the Bahamas. Total amounts of food biomass explained variation in male, but not female, body size on six Bahamian islands, giving rise to significant differences in SSD. Laboratory experiments on a captive colony of A.sagrei confirmed that variation in SSD was mediated by the effects of prey biomass on developmental plasticity in males, but not females. Indeed, males grew faster and attained larger sizes as adults under high-food treatments than under restricted diets, whereas adult females retained similar body sizes under both conditions. Our results indicate that the amount of food available can influence intersexual variation in body size within a vertebrate species. Sex-specific developmental plasticity may be favoured if it allows individuals to take advantage of varying levels of food opportunities offered by different habitats, by reducing competition between the sexes. As such, plasticity in response to food availability may have played a role in the invasion success of A.sagrei. This study adds to our growing understanding of the effect of resource availability in shaping SSD in reptiles and lends further support to the condition-dependent hypothesis, according to which the larger sex should display greater plasticity in growth in response to environmental conditions.