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Why Are Microbes Such an Evolutionary Success Story?

Which traits do microbes have that make them so good at survival?

  fossilized microbes
3.5 billion-year-old microbes
© David Phillips/Visuals Unlimited

Microbes have been around longer than ANYthing else on earth—longer than dinosaurs, plants or people. Here's the clue to prove it: fossils of single-celled creatures that date back at least 3.5 BILLION years! We humans only came on the scene about 2 million years ago.

If you imagine all time since the Earth began as a single day...

bacteria appeared at dawn
© 1999 Eric S. MacDicken

...microbes would have appeared sometime around 5:00 a.m...

dinosaurs appeared at 10:00 p.m.
© 1999 Eric S. MacDicken

...dinosaurs don't pop up until around 10:00 at night...

humans appeared at midnight
© 1999 Eric S. MacDicken

...and we humans don't figure in until just seconds before midnight!

Microbes developed when the Earth was still relatively new, a mass of steaming lava, boiling water and a swirl of methane, ammonia and other smelly gases. Out of these basic elements, proteins—the building blocks of life—developed. These proteins came together to form bacteria, the first creatures that could reproduce themselves and contained a genetic blueprint, or DNA. Early cells eventually developed into more complex single-celled creatures, such as the first algae and protozoa. For more details on how all this might have happened and the impact microbes have had on the development of our planet, check out this detailed web site on the Origins of Life made by the folks at NASA.

Microbes became so good at survival that they've continued to live on the planet through today and they are now EVERYwhere. If all the microbes on and in the Earth could be gathered in one place, they would take up more space than all the animals put together!

There are a lot of clues that tell us why microbes have been such an evolutionary success. Here are the top three:

  1. DNA: The Blueprint for Life
  2. Microbial Reproduction
  3. Mutations Make a Hardy Microbe