The behavior is often shaped by natural selection. The behavior that is favored by nature will increase the organism’s fitness. As a result, the organism will survive and such behavior, which is influenced by the genes, will spread through a population.

Humans can learn classical conditioning using a stimulus that is associated with either a positive or negative experience. For example, classical conditioning occurs when a kid learns a crying behavior when he sees an injection. When a kid cries due to the pain that he felt when the needle was pierced in his body, the next time he sees an injection, he would exhibit a learned behavior–crying. His response was associated with his previous experience.

Animals respond to the changes that occur in the environment by altering their behaviors. The behavior cycles that occur every day is called the circadian rhythms. On the other hand, there are behavior cycles that occur seasonally. Examples of behavior changes that are related to environmental cycles include the hibernation during extreme winter climates and migration when there is a scarcity of food and other resources.

When animals stay in groups, they have higher survival and reproductive advantages. When they are seen in groups, they protect each other and their territory. This is the reason why many predators prefer an organism that is alone and they tend to avoid preys that are a part of a group.

As a part of the social behavior of animals, they communicate with one another by using the following:

a. visual signals (gestures, color patterns, and displays)
b. sound signals (sound and vibration)
c. chemical signals (pheromones)
d. language (combination of sound, gestures, and symbols)

Here are the two ways in which animal behaviors influence their evolutionary fitness:

a. Chemical signals such as pheromones play an important in the reproduction of species. As soon as an organism releases pheromones, it may signal other organisms that it is ready for mating. The ability of an organism to detect pheromones indicate an increase in the reproductive fitness of species. Eventually, this trait will spread through the population.

b. When animals stay in groups, particularly with their relatives, they would gain higher survival and reproductive advantages. When they are seen in groups, they protect each other and their territory against predators. More importantly, when relatives stay together, they have higher chances of passing down traits to their next generation. This increases the chances of the offspring to share many similar traits with their relatives.