One possible explanation for the prevalence of sexual reproduction in animal species is that in the context of predator-prey dynamics, sexually reproducing prey are better able to evade predators than their asexual counterparts. This is known as the Red Tooth hypothesis, a term coined by French (2010). It is a special case of the more generic Red Queen hypothesis, which explains the prevalence of sex not only in terms of advantages to prey but also in terms of advantages to hosts in the face of pathogens, based on the assumption that pathogen-host and predator-prey dynamics are analogous. In this study, we test the Red Tooth hypothesis using individual-based computer modeling simulations, where additional predators are introduced during the simulation process for sexual, asexual and facultative species. Our results indicate that after the introduction of increased predation, sexual species have significantly higher escape ratios vs. their asexual counterparts, explainable by the higher energy levels of sexual prey vs. asexual prey. However, there is a significant decrease in population levels of sexual prey vs. asexual prey. This lower population level of sexual prey may be explainable by the fact that sexual and asexual prey evolve different strategies in response to increased predation: Whereas sexual prey evolve higher energy levels and hence greater body size with a higher ratio of escape behaviors requiring more food which limits population size, asexual prey remain smaller requiring less food and with a lower ratio of escape behaviors but with an increased ratio of successful reproductive attempts resulting in larger populations. An additional factor in lower population levels of sexual prey is a higher kill ratio possibly due to vulnerability related to mating. Moreover, we found that in experimental runs, the species extinction ratio was noticeably lower for sexual vs. asexual prey after the 15,000th time step following increased predation, albeit below the threshold of statistical significance. Our results show that sexual reproduction may be selected in predator-prey systems given the lower rate of species extinction in support of the Red Tooth hypothesis

有性繁殖在动物物种中盛行的一种可能解释是，在捕食者-猎物动态的背景下，有性繁殖的猎物比无性繁殖的猎物更能逃避捕食者。这被称为红牙假说，这是由 French (2010) 创造的术语。这是更通用的红皇后假说的一个特例，它基于病原体 - 宿主和捕食者-猎物动态是类似的。在这项研究中，我们使用基于个体的计算机建模模拟来测试红牙假说，其中在有性、无性和兼性物种的模拟过程中引入了额外的捕食者。我们的结果表明，在引入更多的捕食后，有性物种的逃逸率明显高于无性物种，这可以通过有性猎物与无性猎物的更高能量水平来解释。然而，与无性猎物相比，有性猎物的种群数量显着下降。有性猎物和无性猎物在应对捕食增加时进化出不同的策略可以解释这种较低的性猎物人口水平：而性猎物进化出更高的能量水平，因此体型更大，逃逸行为的比例更高，需要更多的食物限制种群规模，无性猎物仍然较小，需要较少的食物，逃跑行为的比率较低，但成功繁殖的比率增加，导致种群数量增加。性猎物种群数量较低的另一个因素是较高的杀戮率，这可能是由于与交配相关的脆弱性。此外，我们发现在实验运行中，在捕食增加后的第 15,000 个时间步长后，有性与无性猎物的物种灭绝率明显较低，尽管低于统计显着性阈值。我们的研究结果表明，鉴于物种灭绝率较低，因此在捕食者-猎物系统中可能会选择有性繁殖以支持红牙假说 尽管低于统计显着性阈值。我们的研究结果表明，鉴于物种灭绝率较低，因此在捕食者-猎物系统中可能会选择有性繁殖以支持红牙假说 尽管低于统计显着性阈值。我们的研究结果表明，鉴于物种灭绝率较低，因此在捕食者-猎物系统中可能会选择有性繁殖以支持红牙假说