Proximity to crop relatives determines patterns of natural selection in a wild sunflower

Abiotic and biotic heterogeneity result in divergent patterns of natural selection in nature, with important consequences for fundamental evolutionary processes including local adaptation, speciation and diversification. However, increasing amounts of the global terrestrial surface are homogenized by agriculture (which covers nearly 50% of terrestrial vegetated land surface) and other anthropogenic activities. Agricultural intensification leads to highly simplified biotic communities for many taxa, which may alter natural selection through biotic selective agents. In particular, the presence of crops may alter selection on traits of closely related wild relatives via shared mutualists and antagonists such as pollinators and herbivores. We asked how the presence of crop sunflowers (Helianthus annuus) alters natural selection on reproductive traits of wild sunflowers (H. a. texanus). Across two years and multiple sites, we planted replicated paired populations of wild H. a. texanus border...

非生物与生物异质性可在自然界中塑造差异化的自然选择模式，对局部适应、物种形成与物种多样化等核心进化过程具有重要影响。然而，农业占地已达陆地植被覆盖面积的近50%，而农业与其他人类活动正使全球越来越多的陆地表面趋于均质化。农业集约化导致多数类群的生物群落高度简化，进而可能通过生物选择因子改变自然选择进程。尤为值得关注的是，作物的存在可通过共享的互惠共生生物与拮抗生物（如传粉者与植食性动物），改变其近缘野生近缘种的性状选择模式。本研究旨在探究栽培向日葵（Helianthus annuus）的存在，如何改变野生向日葵（H. a. texanus）繁殖性状所受的自然选择压力。本研究在两年时间内、多个样地中种植了野生向日葵（H. a. texanus）的重复配对种群，其种植位点毗邻……