Data from: Habitat heterogeneity favors asexual reproduction in natural populations of grassthrips

Explaining the overwhelming success of sex among eukaryotes is difficult given the obvious costs of sex relative to asexuality. Different studies have shown that sex can provide benefits in spatially heterogeneous environments under specific conditions, but whether spatial heterogeneity commonly contributes to the maintenance of sex in natural populations remains unknown. We experimentally manipulated habitat heterogeneity for sexual and asexual thrips lineages in natural populations and under seminatural mesocosm conditions by varying the number of hostplants available to these herbivorous insects. Asexual lineages rapidly replaced the sexual ones, independently of the level of habitat heterogeneity in mesocosms. In natural populations, the success of sexual thrips decreased with increasing habitat heterogeneity, with sexual thrips apparently only persisting in certain types of hostplant communities. Our results illustrate how genetic diversity-based mechanisms can favor asexuality instead of sex when sexual lineages co-occur with genetically variable asexual lineages.鉴于有性生殖相较于无性生殖存在显著适应性代价，解释真核生物中为何有性生殖仍能广泛盛行，始终是演化生态学领域的一项核心难题。已有多项研究表明，在特定条件下的空间异质性生境中，有性生殖可带来适应性优势，但空间异质性是否普遍能够推动自然种群中维持有性生殖，目前仍无定论。本研究通过调控这类植食性昆虫可获取的寄主植物数量，在自然种群与半自然中宇宙实验条件下，分别对有性与无性蓟马谱系的生境异质性进行了实验操控。在中宇宙实验中，无论生境异质性水平高低，无性蓟马谱系均能快速取代有性谱系。而在自然种群中，有性蓟马的种群存续成功率随生境异质性提升而下降，仅在部分特定寄主植物群落中得以留存。本研究结果表明，当有性生殖谱系与遗传变异丰富的无性生殖谱系共存时，基于遗传多样性的适应性机制会更倾向于选择无性生殖而非有性生殖。