Abstract
Climate and environmental condition drive biodiversity at many levels of biological organization, from populations to ecosystems. Combined with paleoecological reconstructions, palaeogenetic information on resident populations provides novel insights into evolutionary trajectories and genetic diversity driven by environmental variability. While temporal observations of changing genetic structure are often made of sexual populations, little is known about how environmental change affects the long‐term fate of asexual lineages. Here, we provide information on obligately asexual, triploid Daphnia populations from three Arctic lakes in West Greenland through the past 200–300 years to test the impact of environmental change on the temporal and spatial population genetic structure. The contrasting ecological state of the lakes, specifically regarding salinity and habitat structure may explain the observed lake‐specific clonal composition over time. Palaeolimnological reconstructions show considerable regional environmental fluctuations since 1,700 (the end of the Little Ice Age), but the population genetic structure in two lakes was almost unchanged with at most two clones per time period. Their local populations were strongly dominated by a single clone that has persisted for 250–300 years. We discuss possible explanations for the apparent population genetic stability: (a) persistent clones are general‐purpose genotypes that thrive under broad environmental conditions, (b) clonal lineages evolved subtle genotypic differences unresolved by microsatellite markers, or (c) epigenetic modifications allow for clonal adaptation to changing environmental conditions. Our results motivate research into the mechanisms of adaptation in these populations, as well as their evolutionary fate in the light of accelerating climate change in the polar regions.
Highlights
Climate and the environment are major drivers of biodiversity in the broad sense
We address the question if rapid environmental change over the last 200–300 years has affected temporal and spatial population genetic structure of asexual Daphnia populations at the individual lake and landscape scale
Clonal diversity differed between the three lakes (Table 1): of 28 eggs examined in SS4, we found a total of three multilocus genotype (MLG) of which one was dominant throughout three centuries (MLG1)
Summary
Climate and the environment are major drivers of biodiversity in the broad sense. In addition to higher levels of biological organization (e.g., communities and ecosystems), these environmental drivers affect species at the population level, including their temporal and spatial genetic structure and diversity (Pauls et al, 2013; Scheffers et al, 2016). The palaeogenetic record allows the reconstruction of temporal patterns of genetic structure and diversity of aquatic populations and communities These palaeogenetic reconstructions can be coupled with more standard paleoecological proxies (microfossils, geochemical markers, etc.) that reflect environmental and climatic drivers and forcing. Arctic lakes in Greenland provide an ideal system to study long-term dynamics of asexual Daphnia populations in relation to climate change and environmental forcing. We examine genetic diversity in polymorphic microsatellite DNA, and spatio-temporal genetic structure of three Daphnia lake populations in West Greenland near Kangerlussuaq and their relationship with the known regional environmental history. We address the question if rapid environmental change over the last 200–300 years has affected temporal and spatial population genetic structure of asexual Daphnia populations at the individual lake and landscape scale
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
