Answer: 1. Cambrian period, 5. rotation at the shoulder joint. 3. d. notochord, 4. d 2. d.
Explanation:
The answer is scientific theory. It amalgamates scientific law about objects and events that are widely accepted and tested. Scientific theory rationalizes phenomenon, that is not rigorously understood, through science. Examples of scientific theories today are the special relativity theory of Albert Einstein.
The scientist you're looking for is an anthropologist.
Cells, tissue, organs, organ systems, and organisms.