Everybody should understand “Muller’s Ratchet.”
https://en.wikipedia.org/wiki/Muller%27s_ratchet
https://biology.stackexchange.com/questions/93021/mullers-ratchet-and-viruses
https://www.nature.com/articles/348454a0
“Mullers Ratchet”. Very interesting. I have come up with “Handydandy’s Ratchet Theory”. A lot of people used to compare the political swinging pendulum of left then right then left then right, and on and on. I don’t see that as a pendulum anymore. It is more like a ratchet. A ratchet set to tighten, so that every swing to the left tightens the nut, and every swing to the right it merely freewheels. The end result is a steady tightening of the nut.