Program in Ecology, Evolution, and Conservation Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
Program in Ecology, Evolution, and Conservation Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
J Exp Biol. 2018 Nov 26;221(Pt 23):jeb153163. doi: 10.1242/jeb.153163.
For over a century, biologists have proposed a role for phenotypic plasticity in evolution, providing an avenue for adaptation in addition to 'mutation-first' models of evolutionary change. According to the various versions of this idea, the ability of organisms to respond adaptively to their environment through phenotypic plasticity may lead to novel phenotypes that can be screened by natural selection. If these initially environmentally induced phenotypes increase fitness, then genetic accommodation can lead to allele frequency change, influencing the expression of those phenotypes. Despite the long history of 'plasticity-first' models, the importance of genetic accommodation in shaping evolutionary change has remained controversial - it is neither fully embraced nor completely discarded by most evolutionary biologists. We suggest that the lack of acceptance of genetic accommodation in some cases is related to a lack of information on its molecular mechanisms. However, recent reports of epigenetic transgenerational inheritance now provide a plausible mechanism through which genetic accommodation may act, and we review this research here. We also discuss current evidence supporting a role for genetic accommodation in the evolution of eusociality in social insects, which have long been models for studying the influence of the environment on phenotypic variation, and may be particularly good models for testing hypotheses related to genetic accommodation. Finally, we introduce 'eusocial engineering', a method by which novel social phenotypes are first induced by environmental modification and then studied mechanistically to understand how environmentally induced plasticity may lead to heritable changes in social behavior. We believe the time is right to incorporate genetic accommodation into models of the evolution of complex traits, armed with new molecular tools and a better understanding of non-genetic heritable elements.
一个多世纪以来，生物学家提出表型可塑性在进化中的作用，为适应提供了一种途径，除了进化变化的“突变优先”模型。根据这个想法的各种版本，生物体通过表型可塑性对环境做出适应性反应的能力可能会导致新的表型，这些表型可以通过自然选择进行筛选。如果这些最初由环境引起的表型增加了适应性，那么遗传适应就会导致等位基因频率的变化，从而影响这些表型的表达。尽管“可塑性优先”模型的历史悠久，但遗传适应在塑造进化变化中的重要性仍然存在争议——大多数进化生物学家既不完全接受，也不完全摒弃。我们认为，在某些情况下，遗传适应之所以没有被接受，与对其分子机制缺乏了解有关。然而，最近关于表观遗传跨代遗传的报告现在提供了一个合理的机制，通过这个机制遗传适应可能起作用，我们在这里回顾了这项研究。我们还讨论了目前支持遗传适应在社会性昆虫的社会性进化中的作用的证据，这些昆虫长期以来一直是研究环境对表型变异影响的模型，并且可能是特别适合测试与遗传适应相关的假说的模型。最后，我们引入了“社会性工程”，这是一种通过环境修饰首先诱导新的社会表型，然后从机制上研究它，以了解环境诱导的可塑性如何导致社会行为的可遗传变化的方法。我们相信，现在是时候用新的分子工具和对非遗传可遗传因素的更好理解武装起来，将遗传适应纳入复杂特征进化的模型中了。
