Data from: Correlated responses to selection across diverse environments during experimental evolution of Tetrahymena thermophila
Data files
Feb 16, 2026 version files 158.87 KB
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growth_parameters_in_home_vs_away_environment_050824.xls
68.10 KB
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ms3_generations_3875-4125.xls
33.79 KB
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README.md
2.19 KB
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special_media_pops_x_in_y_vs._y_in_x_050824.xls
54.78 KB
Abstract
Correlated responses to selection have long been observed and studied; it remains unclear when they will arise, and in what direction. To contribute to a growing understanding of correlated responses to selection, we used the experimental evolution of the ciliate Tetrahymena thermophila to study direct and correlated responses in a variety of different environmental conditions. One experiment focused on adaptation to two different temperatures and the correlated responses across temperatures. Another experiment used inhibitory concentrations of a variety of compounds to test direct and correlated responses to selection. We found that all populations adapted to the environments in which they evolved. We also found many cases of correlated evolution across environments; few conditions resulted in tradeoffs, and many resulted in a positive correlated response. Surprisingly, in many instances, the correlated response was of a larger magnitude than the direct response. We find that ancestral fitness predicts the extent of adaptation, consistent with diminishing returns epistasis. Unexpectedly, we also find that this pattern of diminishing returns holds across environments regardless of the environment in which evolution occurs. We also found that the correlated response is asymmetric across environments, i.e., the fitness of a population evolved in one environment and assayed in a second was inversely related to the fitness of a population evolved in the second environment and assayed in the first. These results support the notion that positive correlated responses to selection across environments are frequent and worth further study.
https://doi.org/10.5061/dryad.vx0k6djzb
Description of the data and file structure
Growth curves were collected using 96-well plates and a microplate reader.
- ms3_generations_3875-4125.xls contains the data from the 3 genotype 2 temperature experiment. The mean growth rate after 4000 generations is given for each genotype in each evolution and assay condition. Columns show the evolution temperature, the assay temperature (degree C), the population, the initial genotype, the 250-generation bin over which the mean growth rate is calculated, the number of growth rates measured from which the mean is calculated, the mean growth rate, the ancestral growth rate, the relative increase in growth rate, and the absolute change in growth rate.
- growth_parameters_in_home_vs_away_environment_050824.xls contains the performance data from populations evolved and assayed across a variety of environments. Each line indicates an assay condition and an evolution condition. Columns contain growth rate and maximum OD data. Columns show the assay environment, the evolution environment, the mean r-max measured in the evolution environment, the max OD in the evolution environment, the r-max of the ancestor in the evolution environment, the absolute increase in r-max in the evolution environment, the relative increase in r-max in the evolution environment, the max OD of the ancestor in the evolution environment, the absolute increase in max OD in the evolution environment, the relative increase in max OD in the evolution environment, the mean r-max for the given assay condition, the mean max OD for a given assay condition, the r-max of the ancestor, the absolute increase in r-max, the relative increase in r-max, the max OD of the ancestor, the absolute increase in max OD, and the relative increase in max OD.
- special_media_pops_x_in_y_vs._y_in_x_050824.xls contains the same data as the previous file, rearranged so that the performance of x in y is on the same line as the performance of y in x.