Muscle, hair color, height are the 3 most common physical traits affected by the environment.
The left ventricle is responsible for pumping oxygenated blood throughout the entire body, which requires a lot of work and pressure, hence why it is super thick.
Answer:
I. evolved from ancestors that walked
Explanation:
Whales and pythons have vestigial structures, which are structures (hind legs) which are no longer useful to them since they have evolved. The ancestors of the whale and python did use the hind legs but over generations the whale and snake have adapted to new environments and they no longer need them.