I hear folks saying bugs are dying off because of changes in the environment, but shouldn’t bugs be some of the best equipped to handle changes? I imagine they reproduce faster than humans, and so I’d think their genes could adjust faster as well. You’d think we’d be having a worse time than bugs as the environment changes?
In: Biology
Genes aren’t smart. They don’t look out at the environment and change accordingly. They just produce random variations, and if those variations work well in the current environment, that creature reproduces and that gene occurs more often, and if they work poorly, they occur less often.
Take the [peppered moth](https://en.wikipedia.org/wiki/Peppered_moth_evolution) as a buggy example. This is a light colored moth living in England. Occasionally one will hatch and be a very dark color.
Light colored moths are well camouflaged against light colored trees, while dark colored moths are eaten by birds.
During the early Industrial Revolution, coal soot darkened a lot of the surrounding area. Suddenly, the dark moths became way more common and the light moths were rare.
What happened wasn’t a case of the moths getting together and saying “alright lads, time to switch on Dark Mode.” It was a case of birds eating the light colored moths while the dark ones were now well hidden.
Environmental change triggered natural selection, but the key part here as it relates to your question is the adaptive gene *was already in the population.* Dark moths had been showing up presumably for thousands of years, all the coal ash did was flip this from a downside to an upside.
When the environment changes, it will favor the portion of the bug population that is already well adapted to the new environment. If that portion doesn’t exist, then the change will just wipe out the entire population.
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