Klug Hope, Bonsall Michael B
Department of Zoology, University of Florida, Gainesville, Florida 32611, USA.
Am Nat. 2007 Dec;170(6):886-901. doi: 10.1086/522936.
Parental care and filial cannibalism (the consumption of one's own offspring) co-occur in many animals. While parental care typically increases offspring survival, filial cannibalism involves the killing of one's young. Using an evolutionary ecology approach, we evaluate the importance of a range of factors on the evolution of parental care and filial cannibalism. Parental care, no care/total abandonment, and filial cannibalism evolved and often coexisted over a range of parameter space. While no single benefit was essential for the evolution of filial cannibalism, benefits associated with adult or offspring survival and/or reproduction facilitated the evolution of cannibalism. Our model highlights the plausibility of a range of alternative hypotheses. Specifically, the evolution of filial cannibalism was enhanced if (1) parents could selectively cannibalize lower-quality offspring, (2) filial cannibalism increased egg maturation rate, (3) energetic benefits of eggs existed, or (4) cannibalism increased a parent's reproductive rate (e.g., through mate attractiveness). Density-dependent egg survivorship alone did not favor the evolution of cannibalism. However, when egg survival was density dependent, filial cannibalism invaded more often when the density dependence was relatively more intense. Our results suggest that population-level resource competition potentially plays an important role in the evolution of both parental care and filial cannibalism.
亲代抚育和子代自相残杀（吃掉自己的后代）在许多动物中同时存在。虽然亲代抚育通常会提高后代的存活率，但子代自相残杀却涉及杀死自己的幼崽。我们采用进化生态学方法，评估一系列因素对亲代抚育和子代自相残杀进化的重要性。亲代抚育、不抚育/完全抛弃以及子代自相残杀在一定参数空间范围内进化且常常共存。虽然没有单一的益处对于子代自相残杀的进化是必不可少的，但与成年个体或后代的生存和/或繁殖相关的益处促进了自相残杀行为的进化。我们的模型突出了一系列替代假设的合理性。具体而言，如果满足以下条件，子代自相残杀行为的进化会得到增强：（1）亲代能够选择性地吃掉质量较低的后代；（2）子代自相残杀提高了卵的成熟率；（3）卵存在能量益处；或者（4）自相残杀提高了亲代的繁殖率（例如，通过吸引配偶）。仅密度依赖的卵存活率并不利于自相残杀行为的进化。然而，当卵的存活具有密度依赖性时，在密度依赖性相对更强的情况下，子代自相残杀行为更常出现。我们的结果表明，种群水平的资源竞争可能在亲代抚育和子代自相残杀的进化中都发挥着重要作用。
