DOI: 10.5061/dryad.8931zcs02
title: Code from: A disturbing view of life history evolution

description: Code files and figures from life history simulations modelling a
 disturbance regime on life history combinations to consider the effect of
 disturbance on fitness (measured with a framework considering resistance
 and recovery). No data is needed as it is simulated within the code
 scripts; the included supplemental files contain all of the information
 necessary to support the research findings.
description: # Code from: A disturbing view of life history evolution ## **GENERAL
 INFORMATION** This README.txt file was updated on 23/10/2025. **A. Paper
 associated with this archive** Citation: Murray, K.I., Townley, S. and
 Hodgson, D., 2025. A Disturbing View of Life History Evolution. *The
 American Naturalist*. Brief abstract: Species’ lifetime schedules of
 survival, growth and reproduction generally assort along a principal axis
 of variation called the “fast-slow” continuum, with positions attributed
 to the value of producing many, fragile offspring early, versus few,
 high-quality offspring later. Fast species are classically associated with
 surplus or pulsed resources, and slow species with stable, limiting
 resources. Here we demonstrate that the fast-slow continuum can also
 emerge as a zone of highest fitness in the face of unpredictable,
 catastrophic, demographic disturbances, regardless of resource supply,
 competition, or life history trade-offs. Our resilience framework measures
 resistance, recovery, and fitness of stage-structured life histories in
 stochastically disturbed environments. Structured disturbances favour
 either fast or slow life history variants due to their respective weak
 resistance and fast recovery, or strong resistance and slow recovery.
 Demographic disturbance regimes might therefore play an important role in
 shaping nature’s diversity of life histories. The resilience framework is
 a useful tool for understanding species’ demographic and evolutionary
 responses to environmental fluctuations and change. **B. Originators**
 Katie I. Murray^1^, Stuart Townley^2^ and Dave Hodgson^1^ ^1^Centre for
 Ecology and Conservation, Faculty of Environment, Science and Economy,
 University of Exeter, Penryn Campus, Penryn, Cornwall UK ^2^Department of
 Earth and Environmental Sciences, and Environment and Sustainability
 Institute, Faculty of Environment, Science and Economy, University of
 Exeter, Penryn Campus, Penryn, Cornwall UK **C. Contact information**
 Name: Dave Hodgson (corresponding author) Address: University of Exeter,
 Penryn Campus, Penryn, Cornwall UK Email:
 [d.j.hodgson@exeter.ac.uk](mailto:d.j.hodgson@exeter.ac.uk) ## DATA &
 CODE FILE OVERVIEW There are two models each with self-contained code
 files (for simulations and figure composition) and the orginal figures
 (Figures 1-6). The two following code files will generate the figures used
 on software framework R with all necessary packages called in the start of
 the script. Just run the whole code from what it looks like for each
 model. No data is needed as it is simulated within the code scripts; the
 included supplemental files contain all of the information necessary to
 support the research findings. 1. **Model_1__Figures_123.R**:
 Stage-structured productivity (Figures 1-3) 2. **Model_2__Figures_456.R**:
 Delayed maturation model (Figures 4-6) **All figure PDFs are available on
 Zenodo. See the Related Work entry for Supplemental Information.**
 **Figure_1.pdf**: Heatmaps showing the stochastic growth rates for
 combinations of adult (*s*2) and juvenile (*s*1) survival, with contours
 describing adult productivity (*p*2) and panels for different values of
 juvenile productivity (*p*1). All populations disturbed by stage-specific,
 Uniform-distributed, proportional culls with per-timestep
 probability *f* = 0.2. The yellow diamond symbol represents the maximum
 parameter combination over all plots. The areas of block white represent
 the parameter combinations that are not biologically feasible (s1p1 &gt;
 1.2). **Figure_2.pdf**: Heatmaps showing demographic resistance, measured
 as the mean of the log of the ratio of disturbed to undisturbed population
 size per timestep, for combinations of adult (*s*2) and juvenile (*s*1)
 survival, with contours describing adult productivity (*p*2) and panels
 for different values of juvenile productivity (*p*1). All populations
 disturbed by stage-specific, Uniform-distributed, proportional culls with
 per-timestep probability *f* = 0.2. The yellow diamond symbol represents
 the maximum parameter combination over all plots.  **Figure_3.pdf**:
 Heatmaps showing demographic recovery, measured as the mean of the log of
 the ratio of projected to disturbed population size per timestep, for
 combinations of adult (*s*2) and juvenile (*s*1) survival, with contours
 describing adult productivity (*p*2) and panels for different values of
 juvenile productivity. All populations disturbed by stage-specific,
 Uniform-distributed, proportional culls with per-timestep
 probability *f* = 0.2. The yellow diamond symbol represents the maximum
 parameter combination over all plots. **Figure_4.pdf**: Heatmaps showing
 the stochastic growth rates for combinations of adult (*s*2) and juvenile
 (*s*1) survival, with contours describing adult productivity (*p*2) and
 panels for different values of maturation rate (*φ*). All populations
 disturbed by stage-specific, Uniform-distributed, proportional culls with
 per-timestep probability *f* = 0.2. The yellow diamond symbol represents
 the maximum parameter combination over all plots. **Figure_5.pdf**:
 Heatmaps showing demographic resistance, measured as the mean of the log
 of the ratio of disturbed to undisturbed population size per timestep, 
 for combinations of adult (*s*2) and juvenile (*s*1) survival, with
 contours describing adult productivity (*p*2) and panels for different
 values of maturation rate (*φ*). All populations disturbed by
 stage-specific, Uniform-distributed, proportional culls with per-timestep
 probability *f* = 0.2. The yellow diamond symbol represents the maximum
 parameter combination over all plots. **Figure_6.pdf**: Heatmaps showing
 demographic recovery, measured as the mean of the log of the ratio of
 projected to disturbed population size per timestep,  for combinations of
 adult (*s*2) and juvenile (*s*1) survival, with contours describing adult
 productivity (*p*2) and panels for different values of maturation rate
 (*φ*). All populations disturbed by stage-specific, Uniform-distributed,
 proportional culls with per-timestep probability *f* = 0.2. The yellow
 diamond symbol represents the maximum parameter combination over all
 plots.