Final answer:
Anxiety is explained through biological factors from an evolutionary perspective, as it may have helped our ancestors survive by increasing alertness to threats.
Step-by-step explanation:
The emotion of anxiety through the evolutionary perspective on psychology is explained by biological factors. Evolutionary psychology suggests that certain psychological phenomena, including anxiety, may have evolved as adaptations to help our ancestors survive and reproduce. Anxiety could have served as a mechanism to increase alertness and readiness in response to potential threats, aiding in survival. This view aligns with the ultimate biological causes of behavior that focus on genetic impact on behavior patterns, which are adaptive to both the physical and social environment.