Answer:
The genetic variations that are best suited for their enviornment
Explanation:
Those that are not well suited for their environment will die off, leaving only the ones that are suited for it. This species will slowly take hold until the species has adapted and become a completely different one.
Answer:
The genetic variations that are best suited for their environment
Explanation:
This way they may also have a chance to evolve if natural selection kept going until everyone of the species had that trait.