Since the only type of molecule that a gene can code for is a protein, how is it that a trait relating to the metabolism of carbohydrate can be influenced by genes?

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.

the answer u all are looking for is 4000000000000000000000 million years.