https://phys.org/news/2018-11-small-genomes-cells-hot-soils.html

This isn't the case of simply one microbe embracing an economical approach, either; the majority of populations living in the steaming ground have these same traits.

"This isn't an evolutionary study; we are seeing organisms that are competitive in the hot environment when they already have these traits," Shade said. "The populations living nearby in the cooler, ambient temperature zones are different than the organisms living in the thermal areas."