E. coli showing evolution? Yes! Researchers at Michigan State University have been growing Escherichia coli for 25 years, which is over 58,000 generations, in a project called the Long-Term Experimental Evolution project. And during this time, through studying 12 populations of E. coli, they have found that the bacteria continues to adapt to its environment, with no upper limit in sight- even in the 40,00-50,000 generation range, E. coli‘s “fitness” (a measure of how the organism has adapted to its environment) increased by 3-4% per generation!
Another interesting find: several genetic changes that took place over thousands of generations allowed one of the E. coli colonies to develop the ability to eat the chemical citrate in the presence of oxygen (an ability that E. coli hasn’t had since the Miocene epoch!). Careful record-keeping allowed the researchers to look back at previous generations and track the development of this ability.
Just a fun fact for you- it would take almost two and a half million years to look at 58,000 generations of humans. Bacteria and animals with short lifespans can give us incredible insights into genetic changes that we wouldn’t be able to see in humans.