Alan is an adopted child who lives with three siblings, all biological children of his adoptive parents. alan's math skills are far better than those of his adoptive parents or his adoptive siblings. this provides evidence that:

The evidence that could be provided could be stated that the genes of a person is much stronger compared of those familial environment to some of the abilities that the person acquires. It is because it is being portrayed above that Alan is better at Math than of his adoptive parents and his adoptive siblings, in which it made the conclusion.