So important are these "batteries," Dr. Scharf said, that the temperature at which they break down, about 160 Celsius (320 Fahrenheit), is considered the high-temperature limit for life.
Though water within hydrothermal chimneys is at temperatures well above the limit for life (Fournier 1989; Fournier et al. 2014), hydrothermal gradients radiating through pore spaces around these channels establish a range of temperatures and physico-chemical conditions compatible with thermophilic communities (Fig. 5), entirely independent of photosynthesis (Gold 1992; Fisk et al. 1998).
"There isn't a consensus over how small a free-living organism can be, and what the space optimization strategies may be for a cell at the lower size limit for life," Dr. Birgit Luef, a former postdoctoral researcher in Banfield's group who is now at the Norwegian University of Science and Technology in Trondheim, said in the statement.
Currently an Aw of 0.6 is recognized as the lower limit for life [ 6].
Each country's female average life expectancy at birth was used as the upper limit for life when calculating the potential years of life lost [ 16].
In a sense, diffusion rates set the speed limit for life, just as the speed of light sets the limit in the physical world.
Further concentration of thalassic (seawater derived) hypersaline environments leads to the precipitation of magnesium salts thereby forming the absolute limit for life, since magnesium saturated waters (bitterns) are devoid of active life [ 1].
Inhibition of autophagy in adult Drosophila [ 85] or C. elegans [ 86] was found not to affect longevity, however autophagy was required for the increased life span caused by several pharmocologic and genetic manipulations in yeast, Drosophila and C. elegans [ 87- 90], suggesting that autophagy may be limiting for life span under some conditions but not others.
Both metals recorded much lower values than their average concentrations in the Earth's crust as well as the recommended limits for freshwater life.
Extreme vent fluid regimes with temperatures around 250°C as measured on the surface walls of several black smoker chimneys are above the limits for eukaryotic life, currently thought to be about 45 55°C [82].
