Data from: Phase transitions in yeast and bacterial populations under stress

Nonequilibrium phase transitions from survival to extinction have recently
been observed in computational models of evolutionary dynamics. Dynamical
signatures predictive of population collapse have been observed in yeast
populations under stress. We experimentally investigate the population
response of the budding yeast Saccharomyces cerevisiae to biological
stressors (temperature and salt concentration) in order to investigate the
system’s behavior in the vicinity of population collapse. While both
conditions lead to population decline, the dynamical characteristics of
the population response differ significantly depending on the stressor.
Under temperature stress, the population undergoes a sharp change with
significant fluctuations within a critical temperature range, indicative
of a continuous absorbing phase transition. In the case of salt stress,
the response is more gradual. A similar range of response is observed with
the application of various antibiotics to Escherichia coli, with a variety
of patterns of decreased growth in response to antibiotic stress both
within and across antibiotic classes and mechanisms of action. These
findings have implications for the identification of critical tipping
points for populations under environmental stress.