Institute of Ecology, University of Georgia, Athens, Georgia 30602.
Integr Comp Biol. 2005 Nov;45(5):931-44. doi: 10.1093/icb/45.5.931.
An alternative to classic sexual selection hypotheses for sex differentiated pre-mating behavior is that time available for mating-as individuals experience it-along with fitness differences among alternative potential mates, induces choosy versus indiscriminate mating behavior. This alternative hypothesis says that selection has acted so that all individuals flexibly express fitness-enhancing choosy, indiscriminate, and competitive mating behavior, induced by time-varying life histories, environmental and social cues. Key predictions of DYNAMATE, the formal model of adaptively flexible sex role behavior of individuals of both sexes within dynamically changing populations, include: (1) All individuals regardless of sex assess likely fitness outcomes from mating with alternative potential mates before expressing choosy or indiscriminate behavior. (2) Males and females express adaptively flexible, choosy and indiscriminate behavior so that individuals may change their behavior-from moment to moment-to fit dynamically changing circumstances. (3) Indiscriminate behavior of males and (4) choosy behavior of females would often be maladaptive even in species with greater female than male parental investment, when females have longer latencies to receptivity to re-mating than males, and when the relative reproductive rate of males is greater than in females. (5) Whether or not females show choosy behavior will not affect whether or not males exhibit choosy or indiscriminate behavior, and vice versa. (6) When other model parameters are equal, the proportion of individuals of a given sex expressing choosy or indiscriminate mating behavior is a function of the distribution of fitness ratios (a distribution of all fitness differences that would be conferred on an individual by mating with any two sequentially or simultaneously encountered alternative potential mates). (7) Whether same-sex individuals behaviorally compete is a function of the fitness that would be conferred if the strategist won access to a potential mate, but not a function of relative reproductive rate or its proxy, the operational sex ratio. We call for re-evaluation of sex differences in choosy, indiscriminate, and competitive behavior under strong experimental controls that level the ecological playing fields of males and females, i.e., under experimental conditions informing the mechanisms of phenotypic expression. We end with comments on the classic question of questions: why are the sexes as they are?
一种替代经典性选择假说的观点认为，交配时间（个体所经历的时间）以及不同潜在配偶之间的适应度差异，会导致交配前的性别分化行为出现选择性或非选择性。这种替代假说认为，选择会使所有个体灵活地表现出适应性强的选择性、非选择性和竞争性交配行为，这些行为是由时变的生活史、环境和社会线索诱导的。个体在动态变化的种群中性别角色行为的适应性灵活变化的正式模型 DYNAMATE 的主要预测包括：(1)所有个体无论性别如何，都会在表现出选择性或非选择性行为之前，评估与潜在的不同配偶交配可能带来的适应度结果。(2)雄性和雌性都会表现出适应性灵活的选择性和非选择性行为，因此个体可以随时改变行为，以适应动态变化的环境。(3)雄性的非选择性行为和(4)雌性的选择性行为往往是适应不良的，即使在雌性亲代投资比雄性高的物种中也是如此，当雌性对重新交配的接受延迟时间长于雄性时，以及当雄性的相对繁殖率大于雌性时。(5)雌性是否表现出选择性行为不会影响雄性是否表现出选择性或非选择性行为，反之亦然。(6)当其他模型参数相等时，给定性别的个体表现出选择性或非选择性交配行为的比例是适应度比值分布的函数（即与任何两个依次或同时遇到的替代潜在配偶交配会赋予个体的所有适应度差异的分布）。(7)同性个体的行为竞争是否发生是一个功能，如果策略者获得潜在配偶的机会，就会赋予适应性，但不是功能，而是相对繁殖率或其代理，操作性别比。我们呼吁在强有力的实验控制下重新评估选择性、非选择性和竞争性行为中的性别差异，这些控制可以平衡雄性和雌性的生态竞争环境，即在告知表型表达机制的实验条件下。最后，我们对经典的问题进行了评论：为什么性别是这样的？
