ocean bacteria oxygen humans breathe

After meeting a virus, bacteria can add pieces of its DNA to their own CRISPR system. These new pieces can then pass to their descendants. In this limited way, bacteria can inherit a change gained through an encounter during life, while the CRISPR machinery itself still evolves through ordinary natural selection.

In many lakes, gases produced during decomposition eventually make submerged bodies float. Lake Superior's exceptionally cold deep water slows bacterial activity and gas production. As a result, some bodies remain underwater instead of resurfacing. Temperature can determine what happens long after someone disappears beneath the surface.