Table 2 List of variables used in statistical analyses
From: Evolution of dispersal and life history strategies – Tetrahymena ciliates
Experiment | Variable name | Definition | Estimation method and level |
|---|---|---|---|
Growth | K | Carrying capacity (see eqn 1) | Logistic function fitted at the replicate level to successive densities (time > 0) estimated at the picture level (5 values per time step) |
r | Growth rate (see eqn 1) | Logistic function fitted at the replicate level to successive densities (time > 0) estimated at the picture level (5 values per time step) | |
Final cell density (at K) | Mean density of cells at the last time step (192 hours) | Mean of 5 pictures per replicate | |
Final cell size (at K) | Mean size of cells at the last time step (192 hours) | Mean of all cells of the 5 pictures per replicate | |
Final cell shape (at K) | Mean shape of cells at the last time step (192 hours) | Mean of all cells of the 5 pictures per replicate | |
Starvation | Survival as a density sum over time | Area between the density curve and the density at time = 0 line, starting at time = 8 h which was the mean peak density for all strains | Curves defined by successive values through time of the mean of the 5 pictures per replicate |
Mean maximal cell elongation | Difference between longest shape and start shape, expressed in percentages of start shape | Estimated on means of all cells in the 5 pictures per replicate | |
Variance in maximal cell elongation | Difference between the 95th upper percentile and the mean of the shape distribution at the time when the maximal elongation is reached, expressed as percentage of the same difference at start | Estimated on means of all cells in the 5 pictures per replicate | |
Elongation persistence | Sum of elongation over time, i.e. area between the shape curve and the shape at time = 0 line, starting at time = 8 h | Curves defined by successive values through time of the mean of the 5 pictures per replicate | |
Frequency of putative disperser morphs | Frequency of disperser morphs observed at time = 8 h | Mean of the 5 values per replicate (recorded on each sample just after picture was taken) | |
Dispersal | Initial cell shape | Mean shape of cells in the initial tube | Mean of all cells of the 10 pictures per block |
Dispersal rate | Proportion of cells in the target tube at the end of the experiment | Computed as a combination of parameter values at the replicate level | |
Cell elongation | Difference between mean cell shape in target tube and start tube, expressed as percentage of the shape in start tube 1 | Computed as a combination of parameter values at the replicate level | |
Colonization | Colonization probability | Proportion of tubes where a cell population developed from the single cell added to the tube |