WIKIMEDIA, BRIAN BAER AND NEERJA HAJELAIn a 2013 Science paper, researchers running the Long-Term Evolution Experiment (LTEE)—a project that has been monitoring 12 flasks of Escherichia coli for almost three decades—predicted that the bacteria would continue to adapt to their never-changing environment forever. Now, two years and 10,000 bacterial generations on, it’s clear that their prediction is holding true. The team’s latest report, published in Proceedings of the Royal Society B today (December 16), shows that the fitness of the bacterial populations is indeed continuing to improve.
“We would certainly expect, in the real world, where environments are more heterogeneous, where populations are coevolving with other populations, that evolution is going to continue,” said ecologist and evolutionary biologist John Thompson of the University of California, Santa Cruz, who did not take part in the study. “But what this [paper] says is that, even in the absence of any external forces . . . evolution is going to be relentless nonetheless.”
In 1988, evolutionary biologist Richard Lenski of Michigan State University initiated the LTEE. His team divided one starter culture of E. coli into 12 separate flasks and, for the last 27 years, those 12 cultures have been kept in identical conditions, being diluted by a factor of 100—to allow for growth—with the ...
