Phylogenetic
Scientist use a phylogenetic tree to track the evolutionary history of a species.
I think that the best phrase to fit into the blank is a "scientific theory".
A scientific theory is developed through experiments which use the scientific method, and a theory can be improved if additional data is available or if people provide suggestions which make the theory fit the data better.
The list that is composed of substances that are widely used for many years without apparent ill effects is the GRAS. GRAS is an abbreviation for generally recognized as safe; it is an American food and drug adminstration designation where chemical or substance added to food is considered safe by experts, and therefore, it is exempted from the usual federal food, drug, and cosmetic Act.
Melanin
is
the
answer
you're
looking
for
I can t find out the cost, but there is your answer!