Primate Traits and Social Systems

Flashcards covering key vocabulary and concepts related to primate traits, social systems, and evolutionary biology.

Primate Traits

Characteristics including hair, four limbs, five digits, forward-facing eyes, large brain, social behavior, and a slow life history.

Forward-Facing Eyes

Provide binocular vision and depth perception.

Opposable Thumb

Allows for grasping and manipulation of objects.

Slow Life History

Characterized by long lifespan, slow development, and fewer offspring.

Platyrrhines

New World monkeys distinguished by flat noses, three premolars, and often prehensile tails.

Catarrhines

Old World monkeys and apes with narrow noses, two premolars, and no prehensile tails.

Frugivory

A diet primarily consisting of fruits.

Folivory

A diet based primarily on leaves.

Omnivory

Eating both plant and animal material.

Carnivory/Faunivory

A diet consisting mainly of animal tissue.

Quadrupedalism

The mode of movement using all four limbs.

Arboreal

Living primarily in trees.

Terrestrial

Living primarily on the ground.

Brachiation

A method of moving by swinging from branch to branch.

Suspensory

The ability to hang from branches.

Knuckle Walking

A mode of locomotion where some apes walk on their knuckles.

Bipedalism

Walking on two legs.

Group Living Benefits

Advantages of living in groups include predator protection, food finding, and learning behaviors.

Group Living Costs

Disadvantages that include competition and the risk of disease transmission.

Social System

The composition of individuals within a group.

Mating System

Patterns of reproductive strategies within species.

Monogamy

One male mates with one female.

Polygyny

One male mates with multiple females.

Polyandry

One female mates with multiple males.

Polygynandry

Multiple males and females mating together.

Sexual Dimorphism

Physical differences in size or appearance between male and female members of a species.

Female Reproductive Success

Limited by energy resources, pregnancy, and offspring care.

Male Reproductive Success

Limited by access to females.

Paternity Certainty

Confidence regarding the genetic relationship between a parent and offspring.

Infanticide

The act of males killing unrelated infants to make females available for reproduction sooner.

Altruism

Behavior that benefits others at a cost to oneself.

Kin Selection

Helping relatives to enhance one's own genetic success.

Inclusive Fitness

The sum of direct and indirect reproductive success.

Alloparenting

Care of young by individuals other than their biological parents.

Theory of Mind

The understanding that others have thoughts and intentions.

Life History

Patterns of growth, reproduction, and lifespan.

Slow Life History

Characterized by long development, high parental care, and fewer offspring.

Fast Life History

Characterized by rapid reproduction and a short lifespan.

Brain Energetics

Approximately 20% of total energy is used by the brain.

Expensive Tissue Hypothesis

The tradeoff between energy allocated to the brain and the gut.

Intermembral Index

The ratio of arm to leg length used to infer locomotion patterns.

Derived Traits

Traits that have evolved more recently, as compared to ancestral traits.

Ancestral Traits

Traits that originated in distant ancestors.

Phylogeny

The evolutionary relationships among species.

Vestigial Structure

Reduced structures with little current function that are derived from an ancestral origin.