Department of Botany, University of Wyoming, Laramie, Wyoming, USA.
Department of Agricultural Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA.
Ecol Lett. 2024 Jul;27(7):e14472. doi: 10.1111/ele.14472.
Rapid evolution of increased dispersal at the edge of a range expansion can accelerate invasions. However, populations expanding across environmental gradients often face challenging environments that reduce fitness of dispersing individuals. We used an eco-evolutionary model to explore how environmental gradients influence dispersal evolution and, in turn, modulate the speed and predictability of invasion. Environmental gradients opposed evolution of increased dispersal during invasion, even leading to evolution of reduced dispersal along steeper gradients. Counterintuitively, reduced dispersal could allow for faster expansion by minimizing maladaptive gene flow and facilitating adaptation. While dispersal evolution across homogenous landscapes increased both the mean and variance of expansion speed, these increases were greatly dampened by environmental gradients. We illustrate our model's potential application to prediction and management of invasions by parameterizing it with data from a recent invertebrate range expansion. Overall, we find that environmental gradients strongly modulate the effect of dispersal evolution on invasion trajectories.
快速进化的扩散能力在范围扩张的边缘可以加速入侵。然而，在跨越环境梯度的种群中，扩散个体常常面临着降低适应性的挑战性环境。我们使用生态进化模型来探讨环境梯度如何影响扩散进化，进而调节入侵的速度和可预测性。在入侵过程中，环境梯度与扩散能力的进化背道而驰，甚至导致在更陡峭的梯度上扩散能力的进化降低。反直觉的是，减少扩散可以通过最小化不适宜的基因流和促进适应来实现更快的扩张。虽然在同质景观上的扩散进化增加了扩张速度的均值和方差，但环境梯度大大降低了这些增加。我们通过用最近无脊椎动物范围扩张的数据对模型进行参数化，说明了我们模型在预测和管理入侵方面的潜在应用。总的来说，我们发现环境梯度强烈调节了扩散进化对入侵轨迹的影响。
