ANTH 1101 Unit 2: Living Primates

What is the historical problem with the concept of race?

Race was often treated as a biological classification, and physical traits were wrongly linked to behavioural, intellectual, psychological, and moral traits.

What is monogenism?

The belief that all humans descended from one original pair.

What is polygenism?

The belief that different races descended from multiple original pairs.

What is a cline?

A gradual change in genetic or phenotypic traits across a geographic area.

What does the phrase “there are no races, only clines” mean?

Human variation is continuous rather than divided into a few discrete biological races.

Approximately how genetically similar are humans?

Humans are approximately 99.6–99.9% genetically identical.

Where does most human genetic variation occur?

Within populations: approximately 85% within populations, 7% within continents, and 8% between continents.

What is the discrete sampling problem?

Comparing a limited set of people from different places can make continuous human variation appear divided into distinct groups.

How is race best described in biological anthropology?

As a social and cultural concept rather than a set of discrete biological categories.

What is homology?

Similarity inherited from a common ancestor.

What is analogy or convergence?

Similarity that evolved independently.

What is a primate example of homology research?

Studying chimpanzee gestures, tool use, or cooperation to help infer traits of our ancestors.

What are common primate grasping adaptations?

Many primates have grasping hands and feet, opposable thumbs and/or big toes, and flat nails rather than claws.

What visual characteristics are common in primates?

Forward-facing eyes, binocular and stereoscopic vision, enclosed eye sockets, reduced snouts, and well-developed visual-processing regions.

What is trichromatic vision?

Vision using three retinal receptor types associated with red, green, and blue wavelengths.

How many teeth do humans, apes, and Old World monkeys generally have?

32 teeth.

How many teeth do New World monkeys generally have?

36 teeth.

What are the two major primate groups?

Strepsirrhines and haplorhines.

What are strepsirrhines?

Primates with moist noses, including lemurs and lorises.

What are haplorhines?

Primates with dry noses, including tarsiers and anthropoids.

What are anthropoids?

Monkeys and apes, including humans.

What are platyrrhines?

New World monkeys from the Americas.

What are catarrhines?

Old World monkeys and apes.

Where do lemurs naturally occur?

Madagascar; they are endemic to the island.

What is adaptive radiation?

The diversification of a group into multiple forms occupying different ecological niches.

What is a tooth comb?

A set of forward-projecting lower teeth used in grooming, found in lemurs and lorises.

How do galagos differ from lorises?

Galagos are fast-moving, good leapers with excellent hearing; lorises and pottos move slowly and rely strongly on smell.

What is notable about slow lorises?

They are venomous.

What do tarsiers eat?

Insects and small vertebrates; the lecture describes them as the only truly carnivorous primate.

Where do tarsiers live, and when are they active?

They live in Southeast Asia and are nocturnal.

What is distinctive about marmoset and tamarin social systems?

They usually form monogamous pairs or polyandrous groups and show extensive paternal care.

What are common traits of capuchins and squirrel monkeys?

They are diurnal, arboreal, omnivorous, and some use tools.

What is a prehensile tail?

A tail adapted to grasp or hold objects; many atelid New World monkeys have them.

What are common traits of colobines?

They are mostly leaf-eaters, have complex stomachs, are mostly arboreal, and may have small home ranges.

What is distinctive about cercopithecines?

They have cheek pouches; many are larger and more terrestrial than colobines.

What is brachiation?

Movement by swinging from branch to branch using the arms.

What is fission-fusion social organization?

A system in which a larger social group separates into smaller subgroups and later reunites.

What is socioecology?

The study of interactions among members of a species and between individuals and their environment.

What is frugivory?

Eating fruit.

What is folivory?

Eating leaves.

What is gummivory?

Eating plant exudates such as gum.

What is faunivory?

Eating animals.

What is granivory?

Eating seeds.

What is insectivory?

Eating insects.

What are the three types of food challenges discussed in the lecture?

Ecological challenges (finding/accessing food), chemical challenges (toxicity or nutrition), and mechanical challenges (effort to obtain or process food).

What is Kleiber’s law?

Metabolic rate scales approximately with body mass raised to the three-quarter power: q₀ ∝ M^(3/4).

How do energy needs differ between small and large primates?

Small primates have high energy needs per unit of body weight but low total needs; large primates have lower needs per unit of body weight but high total needs.

What is Kay’s threshold in the lecture?

Approximately 500 g, presented as an upper threshold for insectivory and a lower threshold for folivory.

What is alloparenting?

Care of young by individuals other than the mother.

Name three benefits of group living for primates.

Protection from predators, access to resources and mates, and help such as alloparenting.

Name four costs of social living.

Disease, aggression, infanticide, and feeding competition.

What is contest competition?

Direct competition for clumped resources.

What is scramble competition?

Indirect competition for dispersed resources, as individuals try to obtain enough before others do.

What is a home range?

The area an animal uses; home ranges may overlap.

What is a territory?

An area an animal actively defends.

When is territoriality more likely to be worthwhile?

When resources are valuable and clumped, making exclusive access worth the costs of defence.

What are the costs of territoriality?

Time and energy spent establishing, patrolling, and monitoring boundaries, plus risks during defence.

What is the main energetic constraint on female mammalian reproduction?

Pregnancy and lactation are energetically expensive.

What often constrains male reproductive success?

Access to females.

What is cooperation?

Social behaviour such as grooming, coalitions, cooperative breeding, territorial defence, hunting, food sharing, and care of young.

What is mutualism in terms of fitness?

Both the actor and the recipient benefit.

What is altruism in terms of fitness?

The actor pays a cost while the recipient benefits.

What is competition in terms of fitness?

The actor benefits at the recipient’s expense.

What is spite in terms of fitness?

Both the actor and the recipient are harmed.

What is the group-selection fallacy?

Assuming a behaviour will evolve because it benefits the group, even if it costs the individuals performing it.

What is a free rider?

An individual that receives the benefits of cooperation without paying the cost of helping.

What is kin selection?

An explanation for how costly behaviour can evolve when it benefits genetic relatives.

What is inclusive fitness?

Direct fitness from an individual's own reproduction plus indirect fitness from effects on relatives’ reproduction.

What is direct fitness?

Fitness gained through an individual's own reproduction.

What is indirect fitness?

Fitness gained through effects on relatives’ reproduction.

What is Hamilton’s rule?

r × b > c: relatedness multiplied by the benefit to the recipient must exceed the cost to the actor.

What does r mean in Hamilton’s rule?

The coefficient of relatedness.

What does b mean in Hamilton’s rule?

The benefit to the recipient.

What does c mean in Hamilton’s rule?

The cost to the actor.

What is the coefficient of relatedness between parent and child?

0.5.

What is the coefficient of relatedness between full siblings?

0.5.

What is the coefficient of relatedness between half siblings?

0.25.

What is the coefficient of relatedness between grandparent and grandchild?

0.25.

What is the coefficient of relatedness between cousins?

0.125.

How is relatedness calculated through a family tree?

Each parent–offspring link contributes a factor of 0.5; add contributions from each path through shared ancestors.

What are three kin-recognition cues?

Spatial cues, familiarity through prior association, and phenotype matching.

What is a spatial cue for kin recognition?

Using location or proximity as an indirect clue to relatedness.

What is familiarity-based kin recognition?

Recognizing relatives through prior association or having encountered them before.

What is phenotype matching?

Recognizing relatives by comparing appearance, smell, or vocalizations with oneself or known relatives.

What is evolutionary disequilibrium in kin recognition?

When a once-reliable cue becomes unreliable after social or environmental conditions change.

What is the difference between kin recognition and kin discrimination?

Recognition means identifying kin; discrimination means treating kin differently from non-kin.

What is reciprocal altruism?

Helping another individual with the possibility that the recipient will repay the help later.

What conditions support reciprocal altruism?

Interactions occur often enough for repayment, individuals track previous behaviour, and they cooperate selectively with reciprocators.

Does reciprocal altruism require repayment in the same form?

No. Repayment does not have to be in the same form or “currency” as the original help.

What is life history?

The pattern and timing of growth, maintenance, and reproduction between birth and death.

What are the three main energy-allocation demands in life history?

Growth, maintenance, and reproduction.

What is a K-selected life-history pattern?

Typically larger body and brain size, long gestation, small litters, low mortality, and long lifespan.

What is an r-selected life-history pattern?

Typically smaller body and brain size, short gestation, large litters, higher mortality, and short lifespan.

How can high predation risk affect life history?

It may reduce the time available to invest in large bodies, large brains, long pregnancies, and long childhoods.

What is senescence?

Age-related decline.

Why does natural selection generally weaken with age?

Younger individuals generally contribute more genes to future generations, so traits affecting survival early in life are often under stronger selection.

Why are primates generally described as K-selected?

They tend to mature slowly, have long gestations, produce small litters, and live relatively long lives.

What is absolute brain size?

The actual size or mass of the brain without adjusting for body size.

Why is relative brain size useful?

It accounts for body size when comparing brains across different animals.

What is allometry?

How one body part grows relative to the whole body or another measurement.