Scientists reveal the lifestyle evolution of wild marine bacteria

This figure shows the likely habitats of vibrio bacteria populations mapped onto a phylogenetic tree for all strains found in the samples taken from the Atlantic Ocean near Plum Island, Mass. Dot colors indicate the predicted habitat of the bacteria (red are believed to attach to zooplankton, yellow to large organic particles, green to small organic particles, and finally blue are free-floating). The outer ring indicates the microbe’s preference for warm weather (gray) or cold (black). The inner ring shows where the microbes were found (attached or free-floating). The 25 shaded bands within show the ecological populations based on habitat and genetic similarity, all of which originated from a common ancestor hundreds of millions of years ago. Populations 9 through 25 are all called V. splendidus, even though they have distinct habitat preferences and genetic lineage distributions. Two of those (15 and 17) appear to be in the process of radiating into a different habitat. Credit: Lawrence David and Dana Hunt, MIT