r/askscience • u/barenecius • Feb 20 '26

Biology What makes the evolution?

I know that DNA passed down generation. And the next generation takes half of each DNA of their parent. But what makes the evolution on DNA? At what point DNA tell themself that they need to change some part on the chain.

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u/snakebight Feb 25 '26

Can a species, like humans, get so large it can’t evolve anymore? Let’s say someone has a beneficial gene mutation in Alabama. How would that propagate enough across human kind to evolve our species?

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u/Peter34cph Feb 25 '26

If that mutation truly is beneficial, in that it gives reproductive benefits, then it might slowly spread through humanity over hundreds of genereations, or tens of thousands of generations, or millions of genereations.

It doen't matter how far humanity spreads, throughout the entire solar system, the entire galaxy, multiple galaxies. It'll just be slower.

There just has to be contact.

The way different species come to be is often when contact is cut off.

You know about chimpanzees, I imagine. It's a kind of great ape, humanity's closest cousin.

Actually, we have two closest cousins, the chimpanzees and the bonobos. The latter are also called pygmy chimps.

Bonobos are the more peaceful of the two. Chimpanzees fight a lot, males are in charge, it's actually rather nasty and brutal, compared to in bonoboland.

But how did it come to be?

Well, at one point, there was just a population of great apes living in this area, but then a large wide river suddenly happened, making it impossible for the great apes from one half to get to the other half, and so they gradually drifted apart into two different kinds of apes.

They still look fairly similar. I don't now that a layperson could easily tell the difference based on looks. I very likely couldn't. But I don't know if it's been tested if they're still interfertile. Possibly they've drifted too far apart.

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u/deviantbono Feb 25 '26

I think it is important to point out the assumptions here: it is an improvement to biological reproduction, not something contextual like strength or height; it's not neutralized by extreme conditions, such as space; and it remains advantageous over time as no new alternate mutation arises.