Behrens Colby, Young Sarah, Arredondo Eric, Dalziel Anne C, Weir Laura K, Bell Alison M
Department of Evolution, Ecology and Behavior School of Integrative Biology, University of Illinois at Urbana-Champaign Urbana Illinois USA.
Department of Biology St. Mary's University Halifax Nova Scotia Canada.
Ecol Evol. 2025 Apr 23;15(4):e70497. doi: 10.1002/ece3.70497. eCollection 2025 Apr.
Parental care can increase the fitness of parents through increased offspring survival but can also reduce reproductive output by limiting time and energy allocated to additional mating opportunities. The evolutionary origin of parental care is often associated with shifts in life-history traits (e.g., high investment in few, large offspring, slow offspring growth), but little is known about whether the evolutionary of care is associated with reciprocal shifts in the same life-history traits. Here, we capitalize on the divergence of parental care between ecotypes of three-spined stickleback () to test for associations between parental care and life-history traits. While males from most stickleback populations provide care, an unusual "white" ecotype has recently lost paternal care. We found support for the hypothesis that the evolutionary loss of paternal care is associated with shifts in female life-history traits; relative to females of the ecotype with paternal care, females of the white ecotype that lack paternal care produced clutches with a similar overall mass and a greater number of smaller eggs, despite their smaller body size, suggesting lower per-offspring investment. We did not detect an ecotypic difference in embryonic development rate, metabolic rate, or offspring age at hatching, contrary to the 'safe harbor hypothesis'. These results support the theory that behavioral traits such as parental care co-evolve with other life-history traits and highlight opportunities for future study of the underlying causal mechanisms.
亲代抚育可以通过提高后代存活率来增加亲代的适合度，但也可能会因限制用于额外交配机会的时间和精力而降低繁殖产出。亲代抚育的进化起源通常与生活史特征的转变相关（例如，对少数大型后代的高投入、后代生长缓慢），但对于抚育行为的进化是否与相同生活史特征的相互转变相关，人们了解甚少。在此，我们利用三刺鱼（）不同生态型之间亲代抚育行为的差异，来测试亲代抚育与生活史特征之间的关联。虽然大多数三刺鱼种群的雄性会提供亲代抚育，但一种不寻常的“白色”生态型最近失去了父本抚育行为。我们发现有证据支持这样的假设，即父本抚育行为的进化丧失与雌性生活史特征的转变有关；与有父本抚育行为的生态型的雌性相比，缺乏父本抚育行为的白色生态型的雌性，尽管体型较小，但所产的一窝卵总体质量相似，但卵的数量更多且单个卵较小，这表明其对每个后代的投入较低。与“安全港假说”相反，我们没有检测到胚胎发育速率、代谢率或孵化时后代年龄方面的生态型差异。这些结果支持了这样一种理论，即诸如亲代抚育等行为特征会与其他生活史特征共同进化，并突出了未来对潜在因果机制进行研究的机会。
