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Microbe Clock

Evolution is often thought of as a process that takes millions of years, but that's not always the case. Single-celled organisms, in particular, ride an evolutionary fast track. Within weeks, a population of bacteria can virtually reinvent itself.

In recent decades, this phenomenon has pitted doctors and researchers against mutating bacteria in an anxious battle over antibiotic resistance.

Experts now estimate that as many as two dozen types of bacteria have evolved resistance to most, if not all, antibiotics available today. A battle that we have been winning handily for 50 years, thanks to advances in medicine, appears now to be an even match.

-> Explore what allows brainless bacteria to challenge
the best of 21st-century medicine.

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