This dataset contains fitness-linked life history traits, environmental data, and protein and gene expression data for Daphnia magna. Life history data were measured in common garden experiments. For each clone of the same genotype across all experiments, size at maturity (distance between the head and the base of the tail spine), age at maturity (first time eggs were observed in the brood chamber), fecundity (total number of offspring released summing first and second brood), and mortality were measured. Critical thermal maximum (CTmax) was measured on the experimental animals. Environmental data consisted of Secchi disk depth (water transparency) ; total phosphorous; and total nitrogen for the years 1971–1999; a record of pesticides 1955–2010; temperature records over the past century 80 km from Lake Ring. Organic and carbonate contents of the sediment was estimated using the loss on ignition (LOI) method. Hb protein data consisted of constitutive Hb protein crude content animals reared in normoxic (saturated oxygen level) conditions at two experimental temperatures, 20 and 30°C. Heat shock protein expression was measured in four heat shock proteins (HSP20, HSP60, HSP70 and HSP90). Total RNA, qPCR, mean CT (cycle threshold) value per sample and per protein were collected. Full details about this dataset can be found at https://doi.org/10.5285/13f878dc-ef87-45d5-be8c-5733c88c30e9

This dataset contains information about hourly temperature variation, phenotypic and genetic change, and change in environmental parameters in a two-year mesocosm study designed to tease apart the impact that phenotypic plasticity and genetic diversity have on rate of adaptation to experimental heatwaves. All data were collected between 2017 and 2019. Thermal data was collected continuously using data loggers. The frequency of natural heatwaves was manipulated using a programmable aquatic mesocosm facility using data collected from real heatwaves from 2006. Phenotypic evolution was tracked using intermittent common garden life-history studies while changes in clone frequency were determined using microsatellite markers to track changes in clone frequency in manipulated populations over two years. Experimental data on zooplankton community dynamics were monitored using intermittent depth integrated sampling of communities in each mesocosm over two years. The work was supported by the Natural Environment Research Council (Grant NE/N016017/1). Full details about this dataset can be found at https://doi.org/10.5285/2ae5e8d3-be36-4517-b80c-c6b91792b769