Two different species cannot live for long duration in the same niche or habitat. This law is:

Step-by-step solution

The Principle of Competitive Exclusion states that two species or populations cannot inhabit the same niche: one will consistently outcompete the other. Allen rule states that in a warmblooded animal species having distinct geographic populations, limbs, ears and other appendages of animals living in cold climate tend to be shorter than in animals of same species living in warm climates. Weismann proposed the theory of the continuity of germ-plasm, a theory of heredity.