Land Adaptations Made Bacteria Lethal Weapons

摘要

The ability of bacteria to cause lethal diseases might be down to their move from sea to land. A new family tree suggests that the move led to modern microbial traits such as thick cell walls, which are key to survival on land. Prokaryotic bacteria, the oldest and most basic form of cellular life, come in a variety of shapes and sizes evolved over billions of years. Tracingrnthis evolutionary history has proved difficult because of bacteria's ability to swap genes easily. To solve this problem, researchers have looked for two sets of genes: one codes for core proteins and the other for ribosomal RNA. These genes are less likely to jump between species, but each method leads to a different tree.rnFabia Battistuzzi of Arizona State University in Tempe and Blair Hedges of Pennsylvania State University in University Park sorted 286 species of bacteria by both their genes and whether they live on water or land. By identifying and eliminating from their analysis repeats in ribosomalrngenes, they were able to reconcile the core protein and ribosomal data.