University of Nevada-Reno, Reno, Nevada, 89557.
Smithsonian Tropical Research Institute, Panama City, Panama.
Evolution. 2020 Jan;74(1):132-144. doi: 10.1111/evo.13862. Epub 2019 Nov 4.
Although the impacts of climate change and invasive species are typically studied in isolation, they likely interact to reduce the viability of plant and animal populations. Indeed, invasive species, by definition, have succeeded in areas outside of their native range and may therefore have higher adaptive capacity relative to native species. Nevertheless, the genetic architecture of the thermal niche, which sets a limit to the potential for populations to evolve rapidly under climate change, has never been measured in an invasive species in its introduced range. Here, we estimate the genetic architecture of thermal performance in the harlequin beetle (Harmonia axyridis), a Central Asian species that has invaded four continents. We measured thermal performance curves in more than 400 third-generation offspring from a paternal half-sib breeding experiment and analyzed the genetic variance-covariance matrix. We show that while the critical thermal limits in this species have an additive genetic basis, most components of the thermal performance curve have low heritability. Moreover, we found evidence that genetic correlations may constrain the evolution of beetles under climate change. Our results suggest that some invasive species may have limited evolutionary capacity under climate change, despite their initial success in colonizing novel environments.
尽管气候变化和入侵物种的影响通常是分开研究的，但它们可能相互作用，降低植物和动物种群的生存能力。事实上，入侵物种根据定义已经在其原生范围之外的地区取得了成功，因此相对于本地物种可能具有更高的适应能力。然而，热生态位的遗传结构限制了种群在气候变化下快速进化的潜力，但在引入地区的入侵物种中，这一结构从未被测量过。在这里，我们估计了中亚物种——红圆斑萤（Harmonia axyridis）在入侵的四个大陆中的热性能的遗传结构。我们在来自父本半同胞繁殖实验的 400 多个第三代后代中测量了热性能曲线，并分析了遗传方差-协方差矩阵。我们表明，虽然该物种的临界热极限具有加性遗传基础，但热性能曲线的大多数组成部分的遗传力都较低。此外，我们发现有证据表明遗传相关性可能限制了气候变化下甲虫的进化。我们的研究结果表明，尽管一些入侵物种在殖民新环境方面取得了初步成功，但它们在气候变化下的进化能力可能有限。
