Oh no, they change that much and sometimes even more. The hump is a sexual selection trait - the bigger the hump, the more likely it is that a male will get to mate. This favors genotypes that lead to a big ol’ hump. While not all pink salmon get a hump that large, the Barry Whites of the humpy salmon world have a great big shoulder boulder that makes the lady fish swoon.
Oh no, they change that much and sometimes even more. The hump is a sexual selection trait - the bigger the hump, the more likely it is that a male will get to mate. This favors genotypes that lead to a big ol’ hump. While not all pink salmon get a hump that large, the Barry Whites of the humpy salmon world have a great big shoulder boulder that makes the lady fish swoon.
Here’s one of those fishy freaks: https://www.landbigfish.com/articles/default.cfm?ID=352
Ahhhh it’s a humpy, I stand corrected. Not familiar with them. That’s absolutely wild!
They’re so weird! Imagine going through your life sleek and swift, just to turn into Quasimodo once you hit puberty. Then you die.