system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 : Why are we taller than our ancestors?

I've been told that it's because of genetics, of our better nutrition etc. What is the exact cause?
gpt
Better nutrition is a good start. Compare the average height in South Korea (5'8 1/2") with the average height in North Korea (5'5").

And that's after just half a century of malnutrition.

Not sure about the rest, but the importance if better nutrition cannot be overstated here.

I can imagine there's been some evolutionary selection in mates favoring taller, stronger, healthier-looking people, as well, but that depends on how far back you go to define "ancestors."