Unit 2: Primates Flashcards
Describe the Great Ape DNA Tree
Orangutans (first to split)
Gorillas (second to split)
Humans (third to split)
Fourth split – Bonobos and chimps
nocturnal
active mostly at night
diurnal
active mostly during the day
conspecified
Species that actively defend territories from incursions by other members of their own species
sexual dimorphism
the observation of substantial differences exist in male and female body size (in the same species); usually occurs when men have to compete with other men over access to females
opposable (as a feature of primates)
A defining characteristic of primates; allows one big digit to point opposite the others that helps grasp things
olfactory (as a feature of primates)
relating to the sense of smell; An unspecialized smelling apparatus is reduced in diurnal primates
molar (as a feature of primates)
Primate molars are unspecialized; grinding teeth at the back of a mammal’s mouth
incisor (as a feature of primates)
Primates have a maximum of two per each side of each jaw; narrow-edged tooth near the front of the mouth for cutting food
canines (as a feature of primates)
Primates have a maximum of one per each side of each jaw; a pointed tooth between incisors and premolars (usually enlarged in carnivores, most primates use it for fighting)
premolar (as a feature of primates)
Primates have a maximum of three per each side of each jaw; a tooth situated between canines and molar teeth
brachiation
a form of locomotion in which primates swing underneath branches (apes use this technique)
binocular vision
the fields of vision of the two eyes overlap so that both eyes percieve the same image (likes to hunt)
stereoscopic vision
each eye sends a signal of the visual image to both hemispheres in the brain to create an image with depth (see in 3-D)
strepsirrhines
A suborder of primates (Lemurs/lorises) with pointer/snoutier noses, no color vision, a tooth comb, reflective layer behind the retina, and a greater emphasis on smell
haplorrhines
All non strepsirrhines (tarsiers, new world monkeys, old world monkeys, apes); have complete orbital closure, dry and simple noses (lower emphasis on smell), color vision, and vascularization to the brain
dental formula
a set of numbers that expresses the standard format of one half of one jaw (read from left to right, in order of incisors, canines, premolars, and molaws)
prehensile
grasping; used to describe tails (this trait is restricted to the largest species of platyrrhine monkeys)
cooperative breeding
A domestic arrangement with a single breeding pair and all the other group members help rear the offspring
basal metabolic rate
the rate at which an animal expands energy to maintain life when at rest
gum
a substance that plants produce in response to physical injury that becomes a source of carbohydrates and calcium for some primates
frugivore
eats mostly fruit
folivore
eats mostly leaves
insectivore
eats mostly insects
gummivore
eats mostly gum/sap
territory
fixed areas that primates usually maintain exclusive access to
dominance relationship
when dominance interactions between two individuals have predictable outcomes
social organization
Variation in groups along size, age, sex composition, and degree of cohesiveness
natal
birth
solitary
Organizations in which females maintain separate home ranges and associate mainly with their dependent offspring, males establish their own territories that may encompass that of another female; both sexes disperse; strepsirrhines and orangutans
polygyny
one male, multiple females per territory; resident males mate with multiple females, females mate with only one male; howler monkeys, some langurs, gelada monkeys, gorillas, and hamadryas baboons
mating system
describes the relationship dynamics in a group
polygymandry
multiple male and multiple female groups; both sexes mate with more than one partner; males usually disperse where females stay in natal groups but sometimes this pattern is reversed; macaques, some baboons, capuchin monkeys, squirrel monkeys, some colobines, spider monkeys, chimps, and bonobos
mating effort
all of the activities leading up to conception; for instance the effort required to locate mates and gain access to them, so this can involve courtship displays, competition with rivals, etc
parenting effort
all of the activities that are related to offspring care after conception occurs; for instance sitting on the nest after eggs are laid or carrying infants place to place
interbirth interval
time between successive births
sexual selection
characteristics that increase male success in competition for mates will spread
intrasexual selection
A type of sexual selection when members of the same sex compete for mates, resources, or status (involves direct and indirect competition); favors large body size, large canines, and other armaments
intersexual selection
A type of sexual selection where one sex chooses a mate from the opposite sex (female choice, usually)
estrus
the period of a female’s reproductive cycle when fertilization is possible
sexual selection infanticide hypothesis
The death of nursing infants hastens resumption of maternal receptivity, so a male who takes over a group/rises to the top may benefit from killing nursing infants because their deaths cause their mothers to become sexual receptive sooner
altruism/altruistic behaviors
behaviors that are beneficial to others but costly to themselves/the actor
mutualism/mutualistic behaviors
behaviors (cooperative) that provide benefits to all participants
kin selection (theory)
the idea that selection favors altruistic alleles if animals interacted selectively with their genetic relatives
Hamilton’s rule
Predicts that altruistic behaviors will be favored by selection if the costs of performing the behavior are less than the benefits multiplied by the coefficient of relatedness between the actor and participant; rb > c
coefficient of relatedness
measures the genetic relationship between interacting individuals
phenotypic matching
a method of kin recognition where primates recognize kin by their likeliness to themselves
grooming
The act of one animal licking another; behavior that has a hygienic functions and friendship functions to create/reinforce social bonds; more common among kin than non-kin because costs are high
affiliative
friendly
coalition
an alliance for combined action
matrilineage
a line of descent traced through a female’s line of family
parent-offspring conflict
the phenomenon of upset when infants are weaned from their parents; due to a fundamental asymmetry in the genetic interests of mothers and their offspring
reciprocal altruism
the idea that altruism among individuals can evolve if altruistic behavior is balanced between partners over time (giving back after you benefit from something)
theory of mind
the ability of a non-human primate to predict what others will do based on their knowledge of the mental states of others
primate
A very diverse group, but all of them have a petrosal bulla, emphasize vision rather than smell (generally), have binocular eyes, and big brains in comparison to body size
gregarious
live in some sort of social rgoup
philopatry
remaining in group of birth
cathemeral
active at random times of the day (usually dawn and dusk but time varies still)
omnivores
eats almost everything
tarsiers
An infraorder of haplorhines with eyes so large they cannot rotate in its socket, but behavior is similar to streppsirrhines
simiformes
Non tarsiers/tarsiiformes (NW Monkeys, OW Monkeys, and apes)
platyrrhines
New World Monkeys (within anthropoidea); mostly diurnal, almost exclusively arboreal, social systems and diets vary by size
catarrhines
Old World Monkeys and Apes; all diurnal, arboreal or terrestrial, social systems vary, have an extra premolar; two major infraorders – old world monkeys and hominoids
cercopithecoidea/Old World Monkeys
Diet and social systems vary, splits into two groups Colobines and Cercopithecines; have shoulder blades on the sides of their rib cade
hominoids
Non-cercopithecoidea in catarrhines; Apes (gibbons, orangutans, chimps, bonobos, gorillas, and humans); mostly gregarious (except orangutans), mostly frugivores (except gorillas), arboreal and terrestrial, diverse social systems; shoulder blades on the back of their rib cade
colobines
A kind of Old World Monkeys with sacculated stomachs (to digest leaves) and reduced or absent thumbs; mostly arboreal and mostly folivores
cercopithecines
A kind of Old World Monkey with cheek pouches for food storage; varying social systems and both arboreal and terrestrial
Describe body size adaptations with relation to primate diets
In general, smaller bodied eat small amounts of high quality food, and larger-bodied primates eat large amounts of low quality food because of Clyber’s Law (BMR doesn’t scale linearly with body size so larger animals need less energy per unit weight); gut and stomach size change on diet – some intestines are longer because it allows the gut to get as much fiber as possible from the food
anthropoids
A sub-group of haplorrhines that includes NWMs, OWMs, and apes
What are the five major taxonomic groups of primates?
Lemurs and lorises, tarsiers, new world monkeys, old world monkeys, apes
social system
the ratio between adult males and females in a group; not inherently related to mating systems
armaments
weapon-like structures that tend to form from male-male competition
secondary sexual characters
traits that function in reproduction but are not necessary for reproduction
ornaments
showy, beautiful features that alter mate choice
Darwin’s Theory of Sexual Selection
Reduced survivorship by males with elaborate structures is compensated by their advantage in reproductive success
male
the sex that produces small mobile gametes (sperm)
female
the sex that produces large relatively immobile gametes (eggs, ova)
strategy
A shorthand for evolved behaviors that are non-conscious decisions that are a product of natural selection
costs & benefits
Trade-offs in reproductive success; traits that maximize benefits and minimize costs are more likely to be selected for
The Bateman Principle
Male reproductive success is more variable than female reproductive success in most species (males depend more on number of copulation partners)
What limits female reproduction?
Access to food because female reproduction is costlier and time consuming
What limits male reproduction?
Access to females because sperm/reproduction is cheap; therefore, men should always be seeking out partners to increase reproductive success
sexual reproduction
A basic rule of mammals – sperm and egg must come together
female gestation
pregnancy by the female; the larger the babies are the longer you are pregnant – primates have large brains and therefore it takes longer
female lactation
mammary glands; more energeticaly costly than gestation; primates have long infant periods
senescence
The process of aging/deterioration of functional characteristics/cells and organisms
How does rank affect reproductive success?
High ranking females tend to eat better (for fights patterned by rank); this has been seen b/c it leads to earlier ages of first reproduction, shorter IBIS, higher infant survival rates, and better survival during a mortality crisis; rank can also promote the quality and quantity offspring
What are the factors of female RS?
Longevity, age, group size, rank, and sociality
lactational amenorrhea
The idea that while a female primate is lactating, they don’t have enough energy to ovulate at the same time; major idea is that the allocation of energy to one offspring comes at the expense of others
weaning
The process of gradually reducing nursing, infants becoming more independent, and the bringing back of energy available for the mother to conceive again (the time of this varies among primates)
direct competition (m-m)
Males fight with each other and form a linear dominance hierarchy that affects access to females
How do low ranking males have babies?
Sneaky copulations and behavioral flexibility (having more than one male per unit to help out, or if they live in communities without dominance hierarchies)
dimorphism
A trait that occurs in two distinct forms/morphs within a given species
indirect competition (m-m)
the sperms fight each other to fertilize the egg
sperm competition
competition between sperm of two or more males for the fertilization of a single female; occurs in multi-male multi-female social systems
sperm plugs
A method of preventing sperm competition – a gelatinous plug that blocks the sperm of other males from reaching the egg (but there is also a baculum which is a bone that dislodges this)
extrapair copulations
Mating with a male that is not her pair-bond partner (in hopes of increasing male investment)
infanticide
The killing of infants (usually being nursed) when a man is POSITIVE they are not the father of that infant; usually follows a change in male residence or status; this allows the female to ovulate instead of nurse so they can have babies with this male instead
paternity confusion
A female counterstrategy to infanticide – females are highly motivated to have sex with every male in a group so that every male has a non-zero chance of being the father (tends to mate with lower ranking primates before max ovulation in cycle)
friendship (f-m)
A counterstrategy to infanticide; females without male friends have the highest increase in the stress hormone cortisol compared to those with a friend; usual exchange is female grooms male in exchange for protection
parous
ready to have a baby – older parous females are more attractive to chimps
dilution/selfish herd effect
A benefit of living in groups – your chance of being eaten is lower in a larger group (being the least worst)
vigilance
A benefit of living in groups – a lot of eyes, so a higher change of someone noticing a threat
active defense
A benefit of living in groups – attacking in a group (mobbing) can sometimes deter a large predator; those who live with higher predation risks are more likely to live in large groups, this is often driven by the number of females in the group
troops
A type of society in which they have predictable membership – they are together all day
fission-fusion
A type of society in which there is predictable community membership, but there is unpredictable party/subgroup membership (smaller groups leave and then come back together sometimes)
scramble competition
Equal access to food (regardless of dominance), so increasing the group size results in less food for every individual because everyone is competing
contest competition
Dominants get access to food over subordinates, so there is competition to be dominant
The Socio-Ecological Model
gibbons
The only kind of apes that are not great apes; they have low sexual dimorphism and are small (~5kgs), live in Asian tropical forests, form pair-bonds, one male one female
orangutans
A kind of great ape with a lot of sexual dimorphism (females 40kg males 100kg - within males there’s flanged and unflanged); females are usually solitary with uni-male polygyny
The Great Ape Phylogeny (in hominoids)
Gibbons and Orangutans from Asia, Gorillas, Chimps, Bonobos, and Humans from Africa ** I think
gorillas
Largest living primates and high sexual dimorphism (females 100kg males 200kg), live in low forests and social uni-male polygyny (one male, a lot of females), and they eat leaves
chimps
Moderate sexual dimorphism (females 40kg males 50kg), frugivores, travel more, fission-fusion communities, disperse at adolescence, mostly solitary with core areas, intense male-male competition
bonobos
Moderate sexual dimorphism (females 30kg, males 40kg), frugivores, generally don’t kill each other — they have sex to solve conflicts likely due to strong female coalitions in these communities
cooperation
When an individual acts in a manner that benefits others (usually at cost to the actor)
assortment
Being with other cooperators — this is key to explaining how altruism evolves
altruism in relation to kinship
Kin biases are ubiquitous in primates - altruistic behaviors are more likely to occur among kin; cooperative breeding occurs and kin influences strength of social bonds
How do primates recognize kin?
This evolves independently of taxa but familiarity and age proximity are common
non-kin cooperation
This usually occurs when there is good reason that you will be compensated for your altruistic behavior later
reciprocity
Theory that you are more likely to cooperate with those who have paid you back before
life history
The timing of key events in an organism’s life cycle (ex. Patterns of growth, development, reproduction, or mortality)
trade-offs/life history theory
Energy is allocated to various trade offs (growth, maintenance, and reproduction are the big three events) — at a specific age, we turn our energy to a different event
extrinsic mortality
When things from the outside that cause you to die (disease, predation, starvation)
What is the advantage of aging before you reproduce?
Delaying maturity (waiting to reproduce) often improves offspring survival (especially of the first) — Trade off between extrinsic mortality and being a bigger mom → selects age at first reproduction
What are the unique aspects of human life history?
Large, fat, relatively undeveloped infants, born way too early given brain size, early weaning (much earlier than expected then what would be expected of a chimp), shorter IBIs, slower development and extended childhood, menopause, long life (esp. Post reproduction)
antagonistic pleitropy
Genes that code for something with positive effects on fitness early in life, but can have negative effects later in life
The Grandmother Hypothesis (why do we live past reproductive age)
There is an evolutionary advantage to ceasing reproduction (menopause) and having a long post-fertile period and at this age, it makes better sense to invest in your kids and grandkids than to continue investing in your own reproduction; by stopping having kids and helping their kids raise grandkids, they are helping their reproductive fitness; Presence of a mother (when maturing) reduces age at first birth
Why do men live long too if they don’t reproduce?
Long-lived males possibly byproducts — sometimes the presence of both grandmothers and grandfathers is not positive (always) because they are usually torn between energy towards their husband and their grandbabies
The Need to Learn Hypothesis (long juvenility)
The idea that primates have a long juvenility because social and ecological complexity takes a long time to learn — juvenile period allows for acquisition of adult competence; it also takes a while for brains to grow
hindbrain
Part of the brain that controls a lot of bodily functions (contains the cerebellum and brain stem)
midbrain
The part of the brain that deals with the senses
forebrain/cerebrum
The decision making & behavioral flexibility part of the brain
absolute brain size
Compares the size of brain between species without taking into account other factors (like body size proportions)
relative brain size
Compares size among species while accounting for body size proportions
relative neocortex size/executive brain ratio
Neocortex mass related to brain mass — (neocortex + stratium) / (brain stem of medulla) = EBR
How does brain size relate to cognitive ability?
Global cognitive ability correlates with absolute brain and relative neocortex size, but is NOT correlated with relative brain size
Why don’t all animals have large brains?
Brain tissue is expensive and requires a lot of energy — energy spent on the brain takes away from energy towards other organs like the gut
The Expensive Tissue Hypothesis
There is an energetic trade-off between the brain and other expensive tissues (ex. gut, immune system) — for some, energy is better allocated to the other expensive tissues
Why do primates have large brains? The Social Brain Hypothesis
Natural selection has favored large brains to negotiate the social arms race – social behaviors in primates are cognitively demanding and flexible compared to most other taxa (which suggests other abilities are just byproducts of a large brain)
Why do primates have large brains? The Ecological Brain Hypothesis
Some types of foraging are more cognitively demanding than others
(Ex. Fruit is harder to find than leaves so fruit eating primates have more folds in neocortex)
Why do primates have large brains? The Behavioral Flexibility Hypothesis
Primates in social groups that will face dilemmas need to learn to be flexible and learn new solutions for different problems
and large brains allow for innovation and behavioral flexibility
cognition
The processing of information and the application of knowledge
mirror self-recognition test
Used to test if primates know they are seeing themselves in a mirror rather than another primate (uses the mark test — if they rub their head they have some indication that they know they see themselves)
human social cognition (is that of children better than that of adult apes)
Studies have found that children and apes perform equally well at physical cognition, but humans outperform apes in social tasks/cognition
infanticide
murdering babies, usually in the feeding stage (* check that terminology)
What are the two subfamilies of NWMs?
Cebidae Pitheciidae
What are the subfamilies of Cebidae?
Atelinae, Aotinar, Callitrichinae, Cebine, Samirinae
How does age affect female reproductive success?
Young mothers are still growing their own brains which requires a lot of energy that would otherwise be put towards the growth of the embryo, they also lack experience and thus have higher infant mortality rates than older mothers
What are the morphological and behavioral adaptations of sperm competition?
Chimps devote the same time to brain production as they do to production of sperm; testes size can sometimes increase (depending on social system); some species like chimps and macaques have sperms that swim faster than that of humans and gorillas
The Bruce Effect
Another female counterstrategy to infanticide – when a new male takes over who isn’t the father of the baby (for sure), pregnant females terminate the pregnancies (*we don’t really know how this happens but estrogen plummets)
