Martin C H, McGirr J A, Richards E J, St John M E
Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA.
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA.
Integr Org Biol. 2019 Aug 14;1(1):obz018. doi: 10.1093/iob/obz018. eCollection 2019.
Biologists are drawn to the most extraordinary adaptations in the natural world, often referred to as evolutionary novelties, yet rarely do we understand the microevolutionary context underlying the origins of novel traits, behaviors, or ecological niches. Here we discuss insights gained into the origins of novelty from a research program spanning biological levels of organization from genotype to fitness in Caribbean pupfishes. We focus on a case study of the origins of novel trophic specialists on San Salvador Island, Bahamas and place this radiation in the context of other rapid radiations. We highlight questions that can be addressed about the origins of novelty at different biological levels, such as measuring the isolation of novel phenotypes on the fitness landscape, locating the spatial and temporal origins of adaptive variation contributing to novelty, detecting dysfunctional gene regulation due to adaptive divergence, and connecting behaviors with novel traits. Evolutionary novelties are rare, almost by definition, and we conclude that integrative case studies can provide insights into this rarity relative to the dynamics of adaptation to more common ecological niches and repeated parallel speciation, such as the relative isolation of novel phenotypes on fitness landscapes and the transient availability of ecological, genetic, and behavioral opportunities.
生物学家被自然界中最非凡的适应性所吸引，这些适应性通常被称为进化新奇事物，但我们很少了解新性状、行为或生态位起源背后的微观进化背景。在这里，我们讨论了从一个跨越从基因型到加勒比鳉鱼适应性的生物组织层次的研究项目中获得的关于新奇事物起源的见解。我们重点研究了巴哈马圣萨尔瓦多岛上新型营养专家的起源案例研究，并将这种辐射置于其他快速辐射的背景下。我们强调了可以在不同生物层面上探讨的关于新奇事物起源的问题，例如在适应度景观上测量新表型的隔离程度、确定促成新奇事物的适应性变异的时空起源、检测由于适应性分化导致的功能失调的基因调控，以及将行为与新性状联系起来。进化新奇事物几乎从定义上来说就是罕见的，我们得出结论，综合案例研究可以提供关于这种罕见性的见解，相对于适应更常见生态位和反复平行物种形成的动态过程而言，比如新表型在适应度景观上的相对隔离以及生态、遗传和行为机会的短暂可用性。
