Article
Extended Data Fig. 10 | Relationship across species between thermal
tolerance of species measured in laboratory studies and predicted from
the Metabolic Index. Critical thermal maxima (CTmax), reported in previous
studies, were measured at the onset of loss of physiological function in a
resting state. The ATmax are predicted from the Metabolic Index, as the
temperature at which the O 2 threshold for metabolic rate in either resting
state (Pcrit) or under sustained activity levels (Pcrit × Φcrit), reaches the mean
atmospheric O 2 pressure, Patm (see Methods, equation ( 10 )). The extrapolation
of Pcrit curves to the atmospheric pressure is based on n = 3 independent
estimates of the linear increase in Eo with temperature (see Methods). Points for
each species are the mean, and error bars show the range among the resulting
n = 3 estimates of ATmax. Data are shown for all species in Fig. 5 , for which all
parameters are available (n = 7). For four out of seven species, the ATmax is
reached before the CTmax, even in a resting state. For all seven species, the active
ATmax is reached at a lower temperature than the CTmax, and is comparable to the
maximum temperature that the species inhabits at atmospheric pressure.