Anthropology 101 Chapter 7

Anything organisms do that involves action in response to internal or external stimuli.

The response of an individual, group, or species to its environment.

Such responses may or may not be deliberate and they aren’t necessarily the results of conscious decision making.

The underlying principles of behavioral evolution lie in the interactions  between a number of environmental and physiological variables.

Pertains to relationships between organisms and all aspects of their environment (temperature, predators,  vegetation, availability of food and water, types of food, disease organisms, parasites, etc.).

Focuses on the relationship between behaviors, natural environment, and biological traits of the species.

Based on the assumption that animals, plants, and microorganisms evolved together.

Behaviors have evolved through the operation of natural selection, or

Some behaviors are influenced by genes and are subject to natural selection the same way physical characteristics are.

Behavior constitutes a phenotype

Individuals whose behavioral phenotypes increase reproductive fitness pass on their genes at a faster rate.

Genes do not code for specific behaviors, however (i.e. aggression, cooperation, etc.)

Species vary in their limits and potentials for learning and behavioral flexibility, set by genetic factors.

Natural selection acts on genetic factors shaped by ecological setting of past and present

The composition, size, and sex ratio of a group of animals.

The social structure of a species is, in part, the result of natural selection in a specific habitat, and it guides individual interactions and social relationships.

Primates are among the most social of animals, and social behavior is one of the major topics in primate research.

The subject is broad, including all aspects of behavior that occur in social settings

Body Size

Larger animals require fewer calories per unit of weight than smaller animals.

Larger animals are better able to retain heat and their overall energy requirements are less than for smaller animals.

The chemical processes within cells that break down nutrients and release energy for the body to use.

• When nutrients are broken down into their component parts, such as amino acids, energy is released
• and made available for the cell to use.

Basal Metabolic Rate (BMR) and Diet

Smaller animals generally have a higher BMR than larger ones.

Consequently, smaller primates require an energy-rich diet high in protein, fats, and carbohydrates

Nutritional needs have evolved along with BMR and body size

Benefits are considered in terms of energy (calories) obtained from food versus costs (energy expended) of obtaining and digesting them.

Leaves are abundant, dense, and support large groups of animals.

Insects are widely scattered, causing animals to feed on them alone or in small groups of two or three

Fruits and nuts occur in clumps and are most efficiently exploited by smaller groups of animals; large groups break up into smaller subunits to feed.

Species that rely on foods distributed in clumps tend to be protective of resources, especially if the feeding area is small enough to be defended.

• These subunits may consist of one-male, multi-female groups (example: baboons) or matrilines (example: macaques)
• that consist of a female, her daughters, and their offspring

One-male units, able to join with others because food is plentiful, form large, stable communities (examples: howlers and baboons)

Predation:

Primates are vulnerable to many predators, including snakes, birds of prey, leopards, wild dogs, lions, and even other primates.

Where predation pressure is high, large communities are advantageous.

These may be multi-male, multi-female groups or congregations of one-male groups.

When a baboon strays too far from its troop,  it is more likely to fall prey to predators.

Leopards are the most serious nonhuman threat to terrestrial primates.

Relationships with Nonpredatory Species: Many primate species associate with other primate and nonprimate species for various reasons, including predator avoidance.

• Dispersal: Members of one sex leave the group in which they were born when they become sexually mature.
• Individuals who leave find mates outside their natal group, so dispersal is believed to decrease the likelihood of close inbreeding.

Characteristics or developmental stages that typify members of a species and influence reproductive rates.

Examples: length of gestation, time between pregnancies, period of infant dependency and age at weaning, age of sexual maturity, and life expectancy.

Unpredictable environments favor shorter life histories and stable ones, longer lives

Today, the slow rate of reproduction increases the threat of extinction for all  the great apes

Most primates are diurnal (of or during the day), but several small-bodied promisians and the owl monkey are nocturnal

Nocturnal primates tend to forage for food alone or in groups of 2 or 3, and use concealment to avoid predators

Virtually all nonhuman primate populations are impacted by human hunting and forest clearing.

These activities disrupt and isolate groups, reduce numbers, reduce resource availability, and eventually can cause extinction.

Group living exposes animals to competition with other group members, so why  not live alone?

Costs of competition are offset by the benefits of predator defense provided by associating with others.

Group living evolved as an adaptive response to a number of ecological variables.

• Many primate societies are organized into dominance hierarchies that impose order and
• establish parameters of individual behavior. 

Higher-ranking animals have greater access to preferred food items and mating partners than lower ranking individuals.

Dominance hierarchies are sometimes called “pecking orders” that change throughout one’s life and are learned

¤Sex

¤Age

¤Aggression

¤Time in the group

¤Intelligence

¤Motivation

¤Mother’s social position

Any act that conveys information to another individual.

Frequently, the result of communication is a change in the behavior of the recipient.

Communication may be the result of involuntary processes or a secondary consequence of an intentional action.

Raised body hair is an example of an autonomic, or unintentional, response.

Gestures, facial expressions, and vocalizations are examples of deliberate communication.

The fear grin, seen in all primates, indicates fear and submission.

Grooming serves to indicate submission or reassurance.

Displays communicate emotional states.

Lead to group disruption, as opposed to affiliative behavior, which promote group cohesion.

Conflict within a group frequently develops out of competition for resources, including mating partners and food items.

Most intragroup aggression occurs in the form of various signals and displays within the context of a dominance hierarchy.

Most tense situations are resolved through various submissive and appeasement behaviors.

Primate groups are associated with a home range where they remain permanently.

Within the home range is a portion called the core area, which contains the highest concentration of predictable resources, and it’s where the group is most frequently found.

The core area can also be said to be a group’s territory, and it’s the portion of the home range defended against intrusion.

Common affiliative behaviors include reconciliation, consolation, and interactions between friends and relatives.

Hugging, kissing and grooming are used in reconciliation.

Relationships are crucial to nonhuman primates and the bonds between individuals can last a lifetime.

Altruism, behaviors that benefit another while posing risk to oneself, are common in primate species.

In most primate societies, sexual behavior is tied to the female’s reproductive cycle--estrus.

Permanent bonding between females and males is not common among nonhuman primates.

Male and female Bonobos may mate even when the female is not in estrus, a behavior that is not typical of chimpanzees.

A type of natural selection that operates on one sex, usually males.

Long-term, this increases the frequency of traits that lead to greater success in acquiring mates.

Sexual selection in primates is most common in species in which mating is polygynous and male competition for females is prominent.

Sexual selection produces dimorphism with regard to a number of traits, most noticeably body size.

One way males increase their chances of reproducing is by killing infants fathered by other males.

Individuals maximize their reproductive success, no matter the effect on population or species.

When an infant dies, its mother resumes cycling and becomes sexually receptive.

An infanticidal male avoids waiting two to three years for the infants to be weaned before he can mate with their mothers.

Infanticidal males don’t kill their own offspring.

Once a male has killed an infant, he subsequently fathers another infant with the victim’s mother.

What data would support the hypotheses?

Cultural behavior is learned; it is passed from generation to generation through observation and instruction.

Nonhuman primate infants, through observing their mothers and others, learn about food items, appropriate behaviors, and how to use and modify objects to achieve certain ends.

More complex, chimpanzee culture includes tools such as termite fishing sticks and leaf sponges.

Viewing nonhuman animals in terms of human motives, and experience and capabilities; emphasizing the importance of humans over everything else

Human brains are larger than primate brains, but the neurological processes are functionally the same.

The necessity of close  bonding with at least one parent

Need for physical contact

Developmental stages and dependence on learning

Capacity for cruelty, aggression, compassion, altruism, with humans more adept at cruelty and compassion and capability to reflect on behavior

Answer: b 

Dominance hierarchies result in dominan tindividuals having priority access to food.

Answer: b

Affiliative behaviors enhance group cohesiveness.

c) includes specific sounds for different categories of predators (air, tree or ground).

Answer: core

In a group’s territory there is usually a core area where the highest concentration of resources can be found.