It would be primary since the writer himself is getting the information from a direct source.
It is said that the materials found in the giant cloud that formed our solar system are comparable to the ones we have in the solar system today, which are Hydrogen and Helium!
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.
It's a fundamental law of how the universe organized.
Answer:
An adequate sample of a population for studies of natural selection should
be large enough to:
represent the genetic variation in the population
Explanation:
