Chapter 4

What Doesn't Kill You

If you missed it, here are Chapter 1, Chapter 2 and Chapter 3

And this is the last chapter I’ve written for now, which means it’s time to cancel your paid subscriptions. Seriously, please cancel, I doubt I’ll be releasing anything else soon and I don’t want any charity.

What Doesn't Kill You

For as long as humans have existed, we have been in an evolutionary arms race against many invisible enemies. From an evolutionary perspective, these enemies want the same thing as us: to survive and reproduce. These enemies are a variety of infectious microorganisms, viruses, bacteria, parasites, etc. And just like us, these micro-organisms have genetic material that can develop random mutations, some beneficial, some not. So, just as natural selection favours mutations that protect people against various infections, those infectious microorganisms develop mutations that make them more infectious.

COVID-19 is a good example of this, the various ‘variants’, Alpha, Delta, Omicron, etc, all came about because the virus accumulated mutations over time. What these mutations have done over time is drastically change the effects of COVID-19 infections. Over time, COVID-19 infections have changed from often severe, frequently deadly, infections, to something more contagious but usually more akin to the flu and cold viruses we are used to. This is because it’s actually detrimental to viruses to be too deadly, if they kill people immediately, it’s harder for them to find new victims, especially when quarantines and other safety measures are implemented. So over time, COVID viruses found the sweet spot to survive and thrive, many people with COVID feel well enough to go out in the world while they are coughing and sneezing, making it easy to find new victims.

Because most of the deaths caused by COVID-19 are in the elderly, people who aren’t in a position to pass on their genes anymore, it’s unlikely that the pandemic has affected our evolution in any major way. But our genome is littered with the effects of past infections. And unfortunately, many of the variants positively selected due to their ability to fight particular infections, are detrimental to us when that particular bug is not around.