DOI: 10.5061/dryad.7pc1h
title: Data from: Rapid evolution leads to differential population dynamics and top-down control in resurrected Daphnia populations

description: There is growing evidence of rapid genetic adaptation of natural
 populations to environmental change, opening the perspective that
 evolutionary trait change may subsequently impact ecological processes
 such as population dynamics, community composition and ecosystem
 functioning. To study such eco-evolutionary feedbacks in natural
 populations, however, requires samples across time. Here we capitalize on
 a resurrection ecology study that documented rapid and adaptive evolution
 in a natural population of the water flea Daphnia magna in response to
 strong changes in predation pressure by fish, and carry out a follow-up
 mesocosm experiment to test whether the observed genetic changes influence
 population dynamics and top-down control of phytoplankton. We inoculated
 populations of the water flea D. magna derived from three time periods of
 the same natural population known to have genetically adapted to changes
 in predation pressure in replicate mesocosms, and monitored both Daphnia
 population densities and phytoplankton biomass in the presence and absence
 of fish. Our results revealed differences in population dynamics and
 top-down control of algae between mesocosms harboring populations from the
 time period before, during and after a peak in fish predation pressure
 caused by human fish stocking. The differences, however, deviated from our
 a priori expectations. An S-map approach on time series revealed that the
 interactions between adults and juveniles strongly impacted the dynamics
 of populations and their top-down control on algae in the mesocosms, and
 that the strength of these interactions was modulated by rapid evolution
 as it occurred in nature. Our study provides an example of an evolutionary
 response that fundamentally alters the processes structuring population
 dynamics and impacts ecosystem features.
description: Mesocosm experiment in
 resurrected daphnia magna populationsData from an outdoor
 mesocosm experiment as presented in the paper: “Rapid evolution leads to
 differential population dynamics and top-down control in resurrected
 Daphnia magna populations”. The experiment was carried out in an open
 grass field at the outdoor experimental area of the laboratory of Aquatic
 Ecology, Evolution and Conservation (ARENA) in Heverlee, Belgium, during
 the summer of 2014. Resurrected Daphnia magna populations from three
 periods, each with a different fish stocking level, were used. The Daphnia
 populations were exposed to two different treatments: with fish (Predation
 treatment) and without fish (Control treatment). The first file (i.e.
 “mesocosm_time_series1.csv”) contains daily measurements of chlorophyll a
 concentration (as a measure of phytoplankton biomass), every three days
 measurements of density of juvenile Daphnia, density of adult Daphnia and
 temperature for the three populations (Pre-fish, High-fish and
 Reduced-fish) in Control and Predator treatments (9 columns and 1705 rows
 including header). The second file (“mesocosm_time_series2.csv”) comprises
 time-series of Total nitrogen and Total phosphorous in mg/L for pooled
 samples of Control and Predator mesocosms (5 columns and 39 rows including
 header).mesocosm_time_series.zip