Six percent loss of genetic variation in wild populations since the industrial revolution

Abstract

Genetic variation underpins population fitness and adaptive potential1,2. Thus it plays a key role in any species probability of long-term persistence, particularly under global climate change. Genetic variation can be lost in a single generation but its replenishment may take hundreds of generations3. For that reason safeguarding genetic variation is considered fundamental to maintaining biodiversity, and is an Aichi Target for 20204. As human activities are driving declines in many wild populations5, genetic variation is also likely declining. However the magnitude of ongoing genetic variation loss has not been assessed, despite its importance. Here we show a 6% decline in within-population genetic variation of wild organisms since the industrial revolution. The erosion of genetic variation has been most severe for island species, with an 18% average decline. We also identified several key taxonomic and geographic information gaps that must be urgently addressed. Our results are consistent with single time-point meta-analyses that indicated genetic variation is likely declining 6,7. However, our results represent the first confirmation of a global decline, and estimate of the magnitude of the genetic variation lost from wild populations.