Ecological success of recently emerged bacterial hybrids living in the wild
Microbial species are one of the most ubiquitous living group on Earth’s biosphere, showing incredible ability to thrive even in ambient conditions to the limit of human endurance. By virtue of their rapid growth, bacteria are ideal for unraveling the molecular mechanisms of many evolutionary processes. Their rapidity to respond to changes has been associated to the combined effect of evolutionary processes, species composition or gene expression shifts. Most of the studies have focused so far on isolation and comparison of cultured bacterial population, while very few data are available concerning free-living bacteria. Therefore, it is still controversial how quickly, to which extent and by which mechanism microorganisms evolve in their natural environment. Two researchers of the University of California, Denef and Banfield, have tried to answer this question, as described in a paper recently published in Science. Their work report evolutionary rate estimates from bacterial populations living in a really challenging site, the hot, humid, low-pH, metal-rich and low-oxygen acid mine drainage in the Richmond Mine (Iron Mountain, CA), over the course of 9 years. This would seem not the ideal model system for conducting such kind of study, for the low accessibility at the sites only in limited …
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