For example, Himalayan rabbits carry the C gene, which is required for the development of pigments in the fur, skin, and eyes, and whose expression is regulated by temperature (Sturtevant, 1913).

An equation states that two expressions are equal in value, for example \(4b − 2 = 6\). An identity is a statement that is true no matter what values are chosen, for example \(4a \times a^2 = 4a ...

This protocol describes how to assess indirectly acquired threat responses in humans. The reaction to the emotional expressions of others is determined by measuring skin conductance responses.