New investigation from Dartmouth College hoisted uncertainty regarding how scientists must interpret observed groupings of bacteria. The study advises forethought with the postulation that bacterial groups are at all times a result of environmental and genetic forces.
The study, appearing in the Proceedings of the National Academy of Sciences, state that unsystematic diversification and extinction of cells could categorize bacteria into taxonomic units just as efficiently as categorization based on selection-driven environmental forces.
Olga Zhaxybayeva, assistant professor of biological sciences at Dartmouth College said that a reliable classification system was the key in understanding microbial biodiversity. He also stated that through their research they found that organizing microorganisms was much trickier than previously thought.
Scientists are at present in conflict over what features to consider when classifying bacteria and other microorganisms. Some support the so-called “periodic selection” model, in which the descendant of the most-fit genotype takes over the population and establishes a new group. Others believe in the “recombination” model, in which the frequent exchange of material between genes within bacterial populations causes organisms to bunch together.
“Not knowing what is driving the organization of microorganisms makes the task of providing fast, accurate identification of bacteria difficult,” said Zhaxybayeva. “Surprisingly, we found that a simple alternative may also explain grouping patterns, eliminating the need to invoke current models.”
The team, guided by Zhaxybayeva, tested the idea that a simple birth-death model of cells can produce microbial clusters that look like groupings observed in nature. Hundreds of genomes within four bacterial groups – Escherichia spp., Borrelia spp., Neisseria spp. and Helicobacter pylori were analyzed which produced patterns indistinguishable from those observed in most genes from three of the four bacterial groups.
As an outcome of the findings, the study urges to check diversification of microbial groups against the proposed birth-death model before calling for more complex explanations.