[LS2-8] Social Behaviors and Evolution
This standard focuses on animal behavior, specifically on the distinction between individual and group behavior, and how group behavior can contribute towards species survival.
Resources for this Standard:
Here’s the Actual Standard:
Evaluate evidence for the role of group behavior on individual and species’ chances to survive and reproduce.
The basic idea behind this standard is that there are group behaviors that can increase the survival and reproductive rate of a population. Group behaviors likely evolved because populations of social organisms share a large portion of their DNA. This shared DNA gives organisms to engage in social behaviors like altruism because it contributes a fitness benefit to genes they carry, even if engaging in the behavior lowers individual fitness and survival.
Comparisons should be made between solitary and social animals, as well as between individual and group behaviors. Further, these dichotomies are not mutually exclusive. Normally, solitary animals (such as snakes) must engage in group or social behaviors in order to reproduce. Likewise, animals that live in a colony exhibit many individual behaviors related to their own survival (such as breathing).
An important point of this whole concept is that most organisms use a combination of group and individual behaviors in order to maximize their fitness and survival. Eusocial organisms (bees, ants, termites) exhibit high levels of group behavior, whereas other social animals show more individual behaviors mixed in with group behaviors.
A little clarification:
The standard contains this clarification statement:
Clarification Statement: Emphasis is on: (1) distinguishing between group and individual behavior, (2) identifying evidence supporting the outcomes of group behavior, and (3) developing logical and reasonable arguments based on evidence. Examples of group behaviors could include flocking, schooling, herding, and cooperative behaviors such as hunting, migrating, and swarming.
Let’s take a look at each one of these points:
Individual vs Group Behavior
Individual behavior is typically carried out by a single organism to increase their chances of surviving and reproducing. Group behaviors are carried out by multiple organisms at the same time, and they contribute to the survival of the group. This is a broad definition, and many behaviors have both individual and group aspects.
The best way to clarify this point for students is to separate the assumed function of each behavior into aspects that support the individual and aspects that support the group. Some behaviors are entirely individual (breathing), some are entirely group-based (bees attacking), and some behaviors are beneficial for both individuals and the group (play-based learning, such as baby wolves
Evidence of Group Behavior
Analyzing evidence of group behavior involves seeing the benefits that a group of organism obtains by expressing group behavior. For example, larger meals obtained through pack hunting shows how a group increases the survival of all individuals in the group. Likewise, protective behaviors in herding animals ensure young individuals survive to adulthood, ensuring the existence of the group.
If no evidence can be found of a benefit to the group, the behavior in question may be an individual behavior. For example, a male deer will rub its antlers on trees to remove the velvet-like covering. This behavior increases the male’s chances of mating, but it does nothing for the entire herd.
Developing Arguments based on Evidence
One of the central aspects of this standard is encouraging students to form their own hypotheses and logical conclusions based on evidence. A great way to do this is to provide measurements, facts, and statistics about various animal behaviors, and help students create their own arguments as to why certain behaviors are individual or group-based. Since the line between individual and group behaviors is blurred, there are many valid arguments for every behavior.