Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK.
Proc Biol Sci. 2021 Jan 13;288(1942):20202825. doi: 10.1098/rspb.2020.2825.
Dispersal polymorphism and mutation play significant roles during biological invasions, potentially leading to evolution and complex behaviour such as accelerating or decelerating invasion fronts. However, life-history theory predicts that reproductive fitness-another key determinant of invasion dynamics-may be lower for more dispersive strains. Here, we use a mathematical model to show that unexpected invasion dynamics emerge from the combination of heritable dispersal polymorphism, dispersal-fitness trade-offs, and mutation between strains. We show that the invasion dynamics are determined by the trade-off relationship between dispersal and population growth rates of the constituent strains. We find that invasion dynamics can be 'anomalous' (i.e. faster than any of the strains in isolation), but that the ultimate invasion speed is determined by the traits of, at most, two strains. The model is simple but generic, so we expect the predictions to apply to a wide range of ecological, evolutionary, or epidemiological invasions.
扩散多态性和突变在生物入侵中起着重要作用，可能导致进化和复杂行为，如加速或减缓入侵前沿。然而，生活史理论预测，对于更具扩散性的菌株，生殖适应性（入侵动态的另一个关键决定因素）可能较低。在这里，我们使用一个数学模型表明，可遗传的扩散多态性、扩散与适应性权衡以及菌株之间的突变的结合会产生意想不到的入侵动态。我们表明，入侵动态取决于组成菌株的扩散和种群增长率之间的权衡关系。我们发现入侵动态可能是“异常的”（即比任何单独的菌株都快），但最终的入侵速度取决于最多两种菌株的特性。该模型简单但通用，因此我们预计这些预测将适用于广泛的生态、进化或流行病学入侵。
