Science commentator Simon Pollard on bacteria and evolution

While human generation is usually 20 to 30 years, bacteria can have a generation time of 15-20 minutes. Such a short time span is ideal for showing how evolution works, and the impact of natural selection on a tiny tweak on a single gene. A recent study has suggested that seeing an organism evolve in just over a week, is far more comprehensible to people, than trying to comprehend the enormous passage of time, given life has been on earth for around 3.5 billion years.