Looking at Evolution through Germs part: I

Or, screwed, screwed, we are all screwed.

When it comes to talking about evolution, I like to go big and old. I mostly base my research on whales with legs, giant snakes, and dinosaurs because , well, I geek out over big animals that lived a while ago. If I could figure out why, I probably wouldn’t have this blog.

Today I’d like to switch things up and talk about evolution that’s happening in modern times, sometimes under our own noses.

Bacteria. The word itself sounds kind of icky. Bacteria themselves are one celled organisms so tiny that more than 100,000 of them could fit on the period at the end of this sentence. Something really interesting about them is exactly how they reproduce and how fast they reproduce.

Bacteria make more of themselves through a neat trick called binary fission. That is, they split (fission) into two (binary). Both copies have they exact same DNA, which I am required by science writer code to call, “the building blocks of life.” Some species of bacteria can double their population in 20 minutes by way of binary fission.


Bacteria reproduction.

What brings us to the subject of evolution is mutation in bacterial reproduction. Evolution itself is tiny genetic mutations spread out through many, many generations. Since generations in bacteria last hours instead of years, these creatures make excellent subjects for evolution.

Mutations are generally a bad thing. Downs syndrome is a mutation. Sickle cell anemia is another one. Sometimes mutations can be neutral, like blue eyes or pointer toes that are longer than big toes. Every once in a great while, something beneficial comes out of a mutation. For many organisms, beneficial mutations typically come in the form of eating or reproducing more efficiently. For bacteria, it’s most often antibiotic resistance.

We live in a world covered in germs, and a world covered in antibiotics. We put antibiotics in ourselves when we get sick, we put antibiotics in the animals we eat, we put antibiotics in our soap. It’s little wonder that when one of these fast-mutating “bugs” gets a gene promoting antibiotic resistance, the new type spreads like wildfire. As you will see in the next post, this can lead to some very hairy situations.