Rapid evolution during range expansion is a key mechanism influencing species’ ability to colonize new habitat. Understanding how selective processes alter expansion speed is thus critical to predicting both the spread of invasive species and responses to climate change. Theory predicts evolution of increased dispersal and fecundity at the leading edge of expansions. However, these traits are often negatively correlated, and what conditions might lead to one trait being favoured over the other are unclear. Further, while most theory assumes populations spread through homogeneously favourable environments, how selective processes acting on dispersal and fecundity alter expansion dynamics in patchy landscapes is not well understood. We investigated the role of landscape fragmentation and trait correlations in determining evolutionary trajectories at the leading edge of range expansions, and how these in turn alter expansion speed. We simulated populations with heritable trade-offs between dispersal and fecundity spreading through one-dimensional landscapes with varying degrees of fragmentation. We found that, in populations with a weak trade-off, the strongest dispersers were selected for at the leading edge. However, in highly fragmented landscapes and with a strong trade-off, fecundity was instead favoured. Expansion speed was strongly correlated with dispersal ability at the leading edge at all levels of patchiness, and variation in expansion speed across replicates increased with fragmentation and trade-off strength. Our findings demonstrate that evolution induced by both landscape structure and trait correlations can alter spread dynamics, and that selective processes imposed by spread per se may not always be dominant in influencing expansion speed.

范围扩展过程中的快速进化是影响物种定居新栖息地能力的关键机制。因此，了解选择性过程如何改变扩张速度对于预测入侵物种的扩散和对气候变化的响应至关重要。理论预测，在扩展的前沿，扩散和繁殖力的增加会逐渐演变。然而，这些特质通常是负相关的，尚不清楚什么条件可能导致一个特质优于另一特质。此外，虽然大多数理论都假设种群分布在均匀有利的环境中，但对散布和繁殖力的选择性过程如何改变斑驳景观中的扩展动态却还没有很好的了解。我们研究了景观破碎化和性状相关性在确定范围扩展前沿的演化轨迹中的作用，以及这些反过来又如何改变扩展速度。我们模拟了在具有分散程度的分散的一维景观中，扩散和繁殖力之间存在可遗传折衷的种群。我们发现，在权衡较弱的人群中，最强的分散器被选为领先者。但是，在高度分散的景观中，并且需要进行权衡取舍，因此有利于繁殖力。扩展速度在所有斑片水平上都与前沿处的分散能力密切相关，并且随着碎片和折衷强度的增加，复制品之间的扩展速度变化也随之增加。