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（anthropogenic pressure），是进化生物学、物种保护与种群管理领域的核心研究议题。尽管狩猎压力持续攀升，欧洲各地的野猪（Sus scrofa scrofa）种群数量仍在持续增长。在受到雄性选择性捕捞的野猪种群中，最初被描述的一雄多雌制交配系统可能会转变为滥交/多夫制（promiscuous/polyandrous）交配系统。这类交配系统的转变意味着，单次繁殖事件中可能有更多雄性成为同一胎幼崽的父本，这或许与种群保留高遗传多样性以及胎仔数增加存在关联。我们针对一个承受高强度捕捞压力的野猪种群开展了长达6年的监测，通过估算每胎幼崽的父本数量对上述假说进行了验证。研究结果显示，相较于其他种群，该种群具有较高且稳定的遗传多样性，同时多父本发生率较高，表明该种群存在滥交/多夫制的交配系统。我们还发现胎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。最后我们讨论指出，多父本现象或许是通过维持遗传与表型多样性，助力该种群实现快速演化的关键因素之一。