What DNA base-pair change created the light-skin form of the human protein from the gene that coded for the dark-skin form

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.

answer axon terminal,synaptic cleft; and motor end plate;