1 Laboratorio de Evolución Molecular y Experimental, Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México , Circuito Exterior s/n, Ciudad de México 04510.
2 Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México , Circuito Exterior s/n, Ciudad de México 04510.
Proc Biol Sci. 2019 Jul 10;286(1906):20190486. doi: 10.1098/rspb.2019.0486.
Climate change is one of the most important threats to biodiversity and crop sustainability. The impact of climate change is often evaluated on the basis of expected changes in species' geographical distributions. Genomic diversity, local adaptation, and migration are seldom integrated into future species projections. Here, we examine how climate change will impact populations of two wild relatives of maize, the teosintes Zea mays ssp. mexicana and Z. mays ssp. parviglumis. Despite high levels of genetic diversity within populations and widespread future habitat suitability, we predict that climate change will alter patterns of local adaptation and decrease migration probabilities in more than two-thirds of present-day teosinte populations. These alterations are geographically heterogeneous and suggest that the possible impacts of climate change will vary considerably among populations. The population-specific effects of climate change are also evident in maize landraces, suggesting that climate change may result in maize landraces becoming maladapted to the climates in which they are currently cultivated. The predicted alterations to habitat distribution, migration potential, and patterns of local adaptation in wild and cultivated maize raise a red flag for the future of populations. The heterogeneous nature of predicted populations' responses underscores that the selective impact of climate change may vary among populations and that this is affected by different processes, including past adaptation.
气候变化是生物多样性和作物可持续性面临的最重要威胁之一。气候变化的影响通常基于物种地理分布的预期变化来评估。然而，基因组多样性、局部适应和迁移很少被纳入未来物种预测中。在这里，我们研究了气候变化将如何影响玉米的两个野生亲缘种——墨西哥类蜀黍和小果野玉米的种群。尽管种群内存在高水平的遗传多样性和广泛的未来栖息地适宜性，但我们预测，气候变化将改变超过三分之二的现代类蜀黍种群的局部适应模式，并降低迁移概率。这些变化在地理上是不均匀的，这表明气候变化的可能影响在不同种群之间会有很大差异。玉米地方品种也存在气候变化对种群的具体影响，这表明气候变化可能导致玉米地方品种无法适应其目前种植的气候。野生和栽培玉米的生境分布、迁移潜力和局部适应模式的预测变化，为未来种群的发展敲响了警钟。预测种群反应的异质性强调了气候变化的选择影响可能在不同种群之间存在差异，这受到包括过去适应在内的不同过程的影响。
