What do you think would happen if you kept cutting off a family's arms over generations? Or would it still be too built-in for a change?
It would not have an affect on the genes. It doesn't necessarily get any more complex than that.
Also a prime example of beneficial mutation is; People who live high up, i.e the Himalayas, are much better at dealing with the air up there than those born at sea level.
Is that mutation or just evolution through natural selection? Where the hunters with better lungs were much better at running, chasing and genuinely staying alive as a result of the harsh environment -- as a result, not only being the fittest, but also being the primary options as others would dissipate faster, they would evolve in that way.
You'd have to give a selective disadvantage to a certain characteristic, like, cutting the arms of those with the longest arms, less of them might survive, and over many generations perhaps people will start getting smaller arms..
But that isn't a result of the arms being cut off specifically -- that's lowering their survival capabilities and probabilities. If you removed the legs of the people with the longest arms, they still would not be able to reproduce as a result -- and as such you would not pass on the genes that held the trait of having long arms.
As such,
over many generations perhaps people will start getting smaller arms.. Rock climbers do this when they go to climb the tallest mountains in the world, they sit at the base/partially up the mountain for weeks, letting their bodies become used to operating with less oxygen.
A few questions.
Do these traits last permanently? Even if it's just a diminished state?
Can this be compared to say, weight training, where you're put under stressful circumstances and when your body has restored itself makes sure it is capable of withstanding more? (The rejuvenation of your body in a less oxygen-concentrated air doesn't take part, of course)
Oh. Then humans haven't changed in a while then, we're suited to "okay at almost everything"
As long as we have enough water, can sustain our temperature at around 37.5 degrees celsius and aren't crushed by the pressure of deep deep water... yeah -- we're fine. We're actually quite good at some things we're not necessarily "meant" to be good at, swimming being one of them.
Oh! I see! We need a drastic thing to happen to undergo a mutation,
Not necessarily. Mutations can be random, they can be cosmetic, they can be beneficial, or a harmful one. Kind of like Sickle-Cell Disease where the cells would be far less effective in absorbing oxygen, however if only one of the alleles of your two genes contained this trait then you'd have red blood cells but some sickle-shaped ones too.
If you was infected with, I believe it's malaria, they could not effect the sickle shaped ones, which as a result would still grant passage for not being entirely screwed.
As a result where malaria was a constant, people with Sickle-Cell Disease would still live on to reproduce in league with those otherwise completely healthy.
- H
