Most bacteria developed outside the sea

2009/01/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Mikrobiologia

Microbiologists from the University of Pennsylvania and the University of Arizona have discovered that most bacteria have evolved from the same anchor, but not at sea, but on land.

The difference lies in temperature. Ancestors of marine bacteria evolved in hydrothermal sources, that is, in high temperature zones, which has consequences on the genomes of these microbes: for example, in the bases of genetic information, the relationship between guanine and cytosine is much stronger than between adenine and thymine. Therefore, in the genome of bacteria that live at very high temperatures, the guanine-cytosine couple is more abundant than the other.

This allows microbiologists to know if the ancestor of each bacterium developed in the sea --in short, a genome capable of resisting high temperature-. The result is clear: of the 9,740 species analyzed, 6,157 did not develop in marine hydrothermal sources.