Barreto Wendell P, Marquitti Flavia M D, de Aguiar Marcus A M
Instituto de Física 'Gleb Wataghin', Universidade Estadual de Campinas, Unicamp, 13083-970 Campinas, SP, Brazil.
Instituto de Física 'Gleb Wataghin', Universidade Estadual de Campinas, Unicamp, 13083-970 Campinas, SP, Brazil; Ecology and Evolutionary Biology, Princeton University, 08544 Princeton, NJ, USA.
J Theor Biol. 2017 May 21;421:146-152. doi: 10.1016/j.jtbi.2017.04.003. Epub 2017 Apr 4.
Polymorphisms are usually associated with defenses and mating strategies, affecting the individual's fitness. Coexistence of different morphs is, therefore, not expected, since the fittest morph should outcompete the others. Nevertheless, coexistence is observed in many natural systems. For instance, males of the side-blotched lizards (Uta stansburiana) present three morphs with throat colors orange, yellow and blue, which are associated with mating strategies and territorial behavior. The three male morphs compete for females in a system that is well described by the rock-paper-scissors dynamics of game theory. Previous studies have modeled the lizards as hermaphroditic populations whose individual's behavior were determined only by their phenotypes. Here we consider an extension of this dynamical system where diploidy and sexual reproduction are explicitly taken into account. Similarly to the lizards we represent the genetic system by a single locus with three alleles, o, y, and b in a diploid chromosome with dominance of o over y and of y over b. We show that this genotypic description of the dynamics results in the same equilibrium phenotype frequencies as the phenotypic models, but affects the stability of the system, changing the parameter region where coexistence of the three morphs is possible in a rock-paper-scissors game.
多态性通常与防御和交配策略相关联，影响个体的适应性。因此，不同形态的共存是不被预期的，因为最适应的形态应该会胜过其他形态。然而，在许多自然系统中都观察到了共存现象。例如，侧斑蜥蜴（Uta stansburiana）的雄性呈现出三种形态，喉部颜色分别为橙色、黄色和蓝色，这与交配策略和领地行为相关。这三种雄性形态在一个由博弈论中的剪刀 - 石头 - 布动态很好描述的系统中争夺雌性。先前的研究将蜥蜴建模为雌雄同体种群，其个体行为仅由其表型决定。在这里，我们考虑这个动态系统的一个扩展，其中明确考虑了二倍体和有性生殖。与蜥蜴类似，我们用一个具有三个等位基因o、y和b的单一位点来表示遗传系统，在一个二倍体染色体中，o对y显性，y对b显性。我们表明，这种对动态的基因型描述导致与表型模型相同的平衡表型频率，但会影响系统的稳定性，改变在剪刀 - 石头 - 布博弈中三种形态共存可能的参数区域。
