Fine-scale population structure, inbreeding risk and avoidance in a wild insect population

The ecological and evolutionary importance of fine scale genetic structure within populations is increasingly appreciated. However, available data are largely restricted to wild vertebrates and eusocial insects. In addition there is the expectation that most insects tend to have such large and high density populations and are so mobile that they are unlikely to face inbreeding risks through fine scale population structuring. This has made the growing body of evidence for inbreeding avoidance in insects and its implication in mating systems evolution somewhat enigmatic. We present a four year study of a natural population of field crickets. Using detailed video monitoring combined with genotyping we track the movement of all adults within the population and investigate genetic structure at a fine scale. We find some evidence for relatives being found in closer proximity, both across generations and within a single breeding season. Whilst incestuous matings are not avoided, population inb...

种群内精细尺度遗传结构（fine scale genetic structure）的生态与演化意义日益受到学界重视。然而，现有数据大多局限于野生脊椎动物与真社会性昆虫（eusocial insects）。此外，学界普遍认为，多数昆虫的种群规模庞大、密度较高且活动能力极强，因此不太可能因精细尺度的种群结构而面临近交风险（inbreeding risks）。这使得学界关于昆虫近交回避（inbreeding avoidance）的日益增多的研究证据，以及其对交配系统演化（mating systems evolution）的启示，显得颇为费解。我们针对田野蟋蟀（field crickets）的自然种群开展了为期四年的研究：结合高精度视频监测与基因分型（genotyping）技术，我们追踪了种群内所有成虫的活动轨迹，并对精细尺度遗传结构展开了研究。我们发现，在跨世代以及单个繁殖季内，亲缘个体空间距离更近的现象存在相关证据支持。尽管并未出现避免近交交配的行为，但种群近交...