Certain species of blind fish living in perpetual darkness in the ocean depths have evolved from ancestors that could see. Research indicates that the brain centers for vision in these fish is degenerating, whereas the brain centers controlling other senses are enlarging. What might be the MOST probable reason for the loss of vision in these fish

Explanation:

Evolution for lack of light. If there is no reason for it you lose the ability but it strengthens other senses. It's compensation. The need to tell if the temperature has increased because of something nearby or ability to feel miniscule movement will increase to compensate for that lack of sense.

there is not 1 highest source of protein, but there are many; meats, fish, poultry, seafood, cheese, eggs, yogurt and milk. the only non complete animal food that is beneficial is gelatin.

sorry if this did not , have a great day!