10.25338/B8H62Z
Lyberger, Kelsey
0000-0003-4903-380X
University of California, Davis
Schoener, Thomas
University of California, Davis
Schreiber, Sebastian
University of California, Davis
Effects of size selection versus density dependence on life histories: a
first experimental probe
Dryad
dataset
2021
2022-04-09T00:00:00Z
2022-04-09T00:00:00Z
en
https://doi.org/10.5281/zenodo.4663189
10537 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
When prey experience size-based harvesting by predators, they are not only
subject to selection due to larger individuals being preferentially
harvested but also selection due to reductions in population density.
Density-dependent selection represents one of the most basic interactions
between ecology and evolution. Yet, the reduction in density associated
with exploitation has not been tested as a possible driving force of
observed evolutionary changes in populations harvested size-dependently.
Using an artificial selection experiment with a mixture of Daphnia clones,
we partition the evolutionary effects of size-based harvesting into the
effects of removing large individuals and the effects of lowering the
population density. We show that both size selection and density-dependent
selection are significant drivers of life-history evolution. Importantly,
these drivers affected different life-history traits with size-selective
harvesting selecting for slower juvenile growth rates and a larger size at
maturity, and low density selecting for reduced reproductive output.
Density and size-selection life-history data Data in the two csv files
were collected from individual Daphnia following the selection experiment.
The column header abbreviations follow. ID (identification of an
idividual), density (high (H) or low (L) density treated), selection
(randomly culled (R) or size-selectively culled (S)), block (indicator of
block), Am (age at maturity), max (estimated maximum size), growth
(estimated growth rate measure), totegg_30 (total reproductive output up
to day 30), size_mat (size at maturity), growth_i (size at first
measurement), growth_f (size at third measurement), growth_rt (an
alternate measure of growth, equal to mm grown per day), max_obs (max
observed size). ind.data.selection.csv ind.data.alt.measures.csv Variance
within lines data Average and standard errors for five life-history traits
(age at maturity, size at maturity, estimated maximum size, days to
half-maximum size, and total reproductive output up to day 30) for each of
eight clonal lines. lines.summary.csv Density over time Abundances from
the microcosms for all treatments and blocks over the three-week
experiment. density.csv R code for running analyses R code Lyberger 2021.R