Department of Biology, University of Dallas, 1845 E. Northgate Dr., Irving, TX, 75062, USA.
Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK.
BMC Ecol Evol. 2021 Oct 20;21(1):189. doi: 10.1186/s12862-021-01925-3.
The 'genetic diversity' hypothesis posits that polyandry evolved as a mechanism to increase genetic diversity within broods. One extension of this hypothesis is the 'genetic diversity for disease resistance' hypothesis (GDDRH). Originally designed for eusocial Hymenoptera, GDDRH states that polyandry will evolve as an effect of lower parasite prevalence in genetically variable broods. However, this hypothesis has been broadly applied to several other taxa. It is unclear how much empirical evidence supports GDDRH specifically, especially outside eusocial Hymenoptera.
This question was addressed by conducting a literature review and posteriorly conducting meta-analyses on the data available using Hedges's g. The literature review found 10 direct and 32 indirect studies with both having a strong publication bias towards Hymenoptera. Two meta-analyses were conducted and both found increased polyandry (direct tests; n = 8, g = 0.2283, p = < 0.0001) and genetic diversity generated by other mechanisms (indirect tests; n = 10, g = 0.21, p = < 0.0001) reduced parasite load. A subsequent moderator analysis revealed that there were no differences among Orders, indicating there may be applicability outside of Hymenoptera. However, due to publication bias and low sample size we must exercise caution with these results.
Despite the fact that the GDDRH was developed for Hymenoptera, it is frequently applied to other taxa. This study highlights the low amount of direct evidence supporting GDDRH, particularly outside of eusocial Hymenoptera. It calls for future research to address species that have high dispersal rates and contain mixes of solitary and communal nesting.
“遗传多样性”假说认为，一妻多夫制是一种增加亲代遗传多样性的机制。该假说的一个延伸是“抗病遗传多样性”假说（GDDRH）。GDDRH最初是为群居膜翅目昆虫设计的，它指出，在遗传变异较大的亲代中，寄生虫的流行率较低，一妻多夫制将随之进化。然而，这一假说已被广泛应用于其他几个类群。目前尚不清楚该假说究竟有多少实证证据支持，特别是在膜翅目昆虫以外的类群。
为了解决这个问题，我们进行了文献综述，并在后一步使用 Hedge's g 对现有数据进行了荟萃分析。文献综述发现了 10 项直接研究和 32 项间接研究，两者都存在强烈的向膜翅目昆虫出版偏倚。进行了两项荟萃分析，都发现一妻多夫制增加（直接测试；n=8，g=0.2283，p<0.0001）和其他机制产生的遗传多样性（间接测试；n=10，g=0.21，p<0.0001）降低了寄生虫负荷。随后的一个调节分析表明，不同目之间没有差异，这表明该假说可能适用于膜翅目以外的类群。然而，由于出版偏倚和样本量小，我们必须对这些结果保持谨慎。
尽管 GDDRH 最初是为膜翅目昆虫开发的，但它经常被应用于其他类群。本研究强调了支持 GDDRH 的直接证据很少，尤其是在膜翅目以外的类群。这呼吁未来的研究关注具有高扩散率和包含独居和群居筑巢混合的物种。
