Data from: On the evolutionary consequences of increasing litter size with multiple paternity in wild boar (Sus scrofa scrofa)

Understanding how some species may be able to evolve quickly enough to deal with anthropogenic pressure is of prime interest in evolutionary biology, conservation and management. Wild boar (Sus scrofa scrofa) populations keep growing all over Europe despite increasing hunting pressure. In wild boar populations subject to male-selective harvesting, the initially described polygynous mating system may switch to a promiscuous/polyandrous one. Such a change in the mating system, where potentially more males sire a litter at one reproductive event, may be associated with the retention of high genetic diversity and an increase of litter size. We tested these hypotheses by estimating the number of sires per litter based on a 6-year long monitoring of a wild boar population subject to particularly high harvesting pressure. Our results show a high and stable genetic diversity and high rates of multiple paternity compared to other populations, thus depicting a promiscuous/polyandrous mating system in this population. We also show that litter size is positively linked to the number of sires, suggesting that multiple paternity increases fecundity. We finally discuss that multiple paternity may be one of the factors allowing rapid evolution of this population by maintaining both genetic and phenotypic diversity.

探究部分物种能否以足够快的速率演化以应对人为压力，是进化生物学、物种保护与管理领域的核心研究方向。尽管狩猎压力持续增大，欧洲全境的野猪（Sus scrofa scrofa）种群数量仍呈增长态势。在经受雄性选择性狩猎的野猪种群中，最初被描述的一夫多妻制交配系统可能会转变为滥交/一妻多夫制交配系统。此类交配系统的改变，即单次繁殖事件中可产生更多父本的幼崽窝，或与维持高水平遗传多样性、增加窝仔数存在关联。我们针对一个承受高强度狩猎压力的野猪种群开展了长达6年的监测，通过估算每窝幼崽的父本数量对上述假说进行了验证。研究结果表明，相较于其他野猪种群，该种群具备高水平且稳定的遗传多样性，同时多父本发生率较高，由此证实该种群存在滥交/一妻多夫的交配系统。此外我们发现，窝仔数与父本数量呈正相关关系，提示多父本现象可提升种群繁殖力。最后我们讨论认为，多父本现象通过维持遗传与表型多样性，或是助力该种群实现快速演化的关键因素之一。