Evolutionary implications of microplastics for soil biota

Environmental context Microplastic particles are increasingly recognised as human-caused pollutants in soil with potential harmful effects on soil microorganisms. Microplastics may also have evolutionary consequences for soil microbes, because the particles may alter conditions in the soil and hence selection pressures. Including an evolutionary perspective in an environmental assessment of microplastics could lead to new questions and novel insights into responses of soil microbes to this anthropogenic stressor. Abstract Microplastic pollution is increasingly considered to be a factor of global change: in addition to aquatic ecosystems, this persistent contaminant is also found in terrestrial systems and soils. Microplastics have been chiefly examined in soils in terms of the presence and potential effects on soil biota. Given the persistence and widespread distribution of microplastics, it is also important to consider potential evolutionary implications of the presence of microplastics in soil; we offer such a perspective for soil microbiota. We discuss the range of selection pressures likely to act upon soil microbes, highlight approaches for the study of evolutionary responses to microplastics, and present the obstacles to be overcome. Pondering the evolutionary consequences of microplastics in soils can yield new insights into the effects of this group of pollutants, including establishing ‘true’ baselines in soil ecology, and understanding future responses of soil microbial populations and communities.