Intro to Physical Anthropology Study Guide Test 2

Vertical Clinging and Leaping (VCL)

- Grasping with flexed knees and ankles - Common in lemurs - Good for mid-canopy mobility (tree trunks) -when an animal grasps a vertical branch with its body upright, pushes off with long hind legs and then lands on another vertical support branch. Animals who move in this way usually have longer legs than arms, long fingers and toes, and smaller bodies. Vertical clinger leapers also tend to have elongated ankle bones, which serve as a lever to help them push off with their legs and leap to another branch.

Brachiation

-- Fast under-branch mobility, thick upper canopy ◆ Extended long limbs ◆ Curved finger bones, reduced thumb ◆ Powerful shoulders ◆ Sometimes prehensile tail, "fingerprints" on tail (New World Monkeys) -BTW, while gibbons are the only true brachiators, all apes and humans have shoulder joints that make them capable of brachiation! -Brachiation involves swinging below branches by the hands. To be an efficient brachiator, a primate needs to have longer arms than legs, flexible shoulders and wrists, a short lower back, and no tail

Modern Primate Classification: clade

-A clade is a grouping of organisms that reflect a branch of the evolutionary tree, a grouping based on relatedness. Clade relationships are determined using derived traits shared by groups of taxa as well as genetic similarities. -An example of a clade would be a grouping that includes humans, chimpanzees, bonobos, and gorillas. These taxa are in what is referred to as the African clade of hominoids. -Nowadays, most scientists prefer to employ evolutionary clades to classify primates: • Strepsirhini (Strepsirhines): • Lorises • Lemurs • Haplorhini (Haplorhines): • Platyrrhines (NW monkeys) • Catarrhines (OW monkeys, apes, humans) • Tarsiers!

Sexual selection

-A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates. -intrasexual selection is selection for traits that enhance the ability of members of one sex to compete amongst themselves ("intrasexual" = within one sex). Intersexual selection is selection for traits that enhance the ability o f one sex to attract the other ("intersexual" = between the sexes).

Behavior

-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 (involve intentional or conscious decision making; opposite: autonomic) -Behaviors can be under strict genetic control (innate = instinctive or impulsive behaviors) ◼ In many birds and mammals, however, innate behaviors can be modified through learning, and those behaviors become more abundant, while the portion of behaviors under strict genetic control decreases ◼ Humans, e.g. control most of their behaviors, yet, there are many examples for impulsive behaviors such as promiscuous sex, getting into a fistfight, etc. ◼ The part of the brain responsible for cognitive functions such as reasoning, forethought, complex problem solving, is the neocortex, which, in humans, has become the largest part of the brain. The prefrontal cortex is a specific part of a brain that controls impulsive behavior

Primate Characteristics

-Common evolutionary history reflected in: -Limbs and locomotion -Teeth and diet -Senses and brain -Behavior -Generalized: -Retain many ancestral mammalian traits that other mammal species lost over time

Primate Traits

-Convergent eyes, Post-orbital bar, Many have trichromatic color vision(the ability to distinguish reds and yellows in addition to blues and greens), Short snouts, Opposable thumbs and big toes, Pentadactyly, Flattened nails, Tactile pads, Highly arboreal, Large brains, Extended life histories, Live in the tropics

sexual dimorphism

-Differences in physical characteristics between males and females of the same species. -Male competition for mates can result in, or increase of, Sexual Dimorphism. Most primate species are polygynous (each male has several females he regularly mates with, while females mate with one male, only). This causes strong male competition for females and often prominent sexual dimorphism.

Catarrhini

-Downward facing, tear-drop shaped nostrils, close together -Arboreal and more terrestrial taxa -On average, largest primates -On average, most sexually dimorphic taxonomic group -2:1:2:3 dental formula -All trichromatic

Biomedical Research

-Drug and cosmetic companies used primates. This is now prohibited. • Behavioral, cognitive experiments continue today • Invasive and non-invasive studies --not all primates are hunted specifically for food. Biomedical researchers use primates as models for understanding human biology and as test subjects for the development of vaccines, drugs, and hormones

Visual Communication

-Facial expressions, important during close-up communication • Gestures, body posturing -Raised body hair, "hair-on-end" ◼ Vocalizations and branch shaking ◼ Displays = visual messages, body language that communicate emotional states Gestures: Dominantly studied in Great Apes ◼ Meaning can be context-dependent ◼ E.g. open hand: ◼ Asking for support OR ◼ Wanting to share food ◼ Chimps and bonobos use more gestures than facial expressions Skin and hair color also visually communicates age, sex • Kin recognition • Species recognition -piloerection, or raising one's hair or fur, is used in aggressive interactions to make an individual appear larger than it actually is. The females of many Old World primate species, including macaques, baboons, and chimpanzees, signal sexual receptivity through changes in the size, shape, and, often, color of their hindquarters, called a sexual swelling. The sexual swelling reaches its maximum size at ovulation.

Bipedalism

-Facultative (occasional) and habitual (usual) bipedality -Owing to generalized structure, many primates have more than one form of locomotion -moving around on two feet (humans) -Some primates will occasionally travel on two feet but do so awkwardly and never for long distances. Among mammals, only humans have evolved to walk with a striding gait on two legs as a primary form of locomotion.

Platyrrhini

-Flat nose with rounded nostrils pointing to the side ---Highly arboreal -Less sexually dimorphic on average -2:1:3:3 dental formula* -Polymorphic color vision*

Primate Diet and Teeth

-Generally omnivorous, reflected in their generalized dentition ◆ Most eat a combination of fruits, leaves, and insects, plants, nuts, seeds, meat ◆ Most have four types of teeth: incisors, canines, premolars and molars usually 2:1:2:3 -primates are heterodont: have different types of teeth

Human as primates

-Genetic relationships: analysis of the genetic relationships of living apes and humans has shown that humans and African apes are closely related -Comparative phenotypes: human morphology is closest to that of the great apes and most similar to African apes (chimpanzees, bonobos, and gorillas) -Among the hominoids, humans show particular affinities with other members of the African Clade, Pan and Gorilla. Humans share over 96% of our DNA with gorillas and over 98% with Pan -Our closest living relatives today are chimpanzees and bonobos.Because of our close relationship, humans share many additional traits in common with Pan. Humans, chimpanzees, and bonobos all live in similar social groups that are characterized by territoriality and male cooperation, among other things.

Primate conservation and primate status

-Hot spots are often considered conservation priorities because protecting these areas can result in the protection of large numbers of species. In addition, some conservation organizations focus on highly charismatic primate species (e.g., primates that are large, closely related to humans, or well-known from zoos, such as the golden lion tamarin) to garner attention and resources for conservation. Of the ~650+ recognized species, ~40% are endangered • Madagascar (home of lemurs) is particularly affected • E.g. greater bamboo lemur • Apes heavily threatened as well

Insectivores

-Insectivores need sharp, pointed molar cusps in order to break through the exoskeletons of insects. Insects are easy to digest, so these primates have simple digestive tract -usually smallest of the primates

Lemurs

-Madagascar -Diurnal, nocturnal or cathemeral -Insectivore, frugivore or folivore -Solitary, pairs, or small to large groups -Vertical clinger leapers, quadrupedal

Bushmeat

-Many primates are hunted for meat, skins, perceived medicinal properties • Many species are harvested faster than what they sustain themselves -Problems with bushmeat bans: • Indigenous, local people often eat primate meat because it's cheaper • The real problem are however commercial hunters, who hunt on a larger scale • Blanket bans on primate meat can threaten welfare of local people who may suffer from food insecurity. .

What is a Primate?

-Primates are mammals • Primate order is best defined in terms of adaptability: • Arboreal, evolutionary and behavioral tendencies. - Today, the Order Primates is a diverse group of animals that includes lemurs and lorises, tarsiers, monkeys of the New and Old Worlds, apes, and humans -All members of this class share certain characteristics, including, among other things, having fur or hair, producing milk from mammary glands, and being warm-blooded. -Placental mammals internally gestate for a longer period of time and give birth to fairly well-developed young who are then nursed. Primates, including ourselves, belong to this last group. Among the diversity of mammalian orders alive today, primates are very likely one of the oldest. -Vertebrate class - Mammalia - Subgroup of placental mammals

Primatology

-Scientific study of living and extinct primates • In natural and built environments (e.g. zoos, laboratories) • Studies: - Primate characteristics - Classification - Primate ecology - Sexual and social behavior - Biomedical studies - Conservation -

Lorises, Pottos and Galagos

-South and Southeast Asia Central Africa -Nocturnal -Insectivore, Frugivore -Solitary -Slow quadrupedal climbers and active quadrupedal runners

Behavioral Ecology Principles and Methods

-Studies the relationship between behaviors, the natural environment, and biological traits of species • Suggests behaviors are adaptations to environmental circumstances, and are acted on by natural selection Methods: Studies free-ranging primates within an ecological and evolutionary framework • Free-ranging: non-captive animals in their natural habitat • Ideally, behavior of wild study groups would be free of human influence -These aspects of primate ecology have significant impacts on every part of a primate's life, including their morphology, physiology, and body size as well as their interactions with other individuals inside and outside their social group. They even play a role in determining whether a primate lives in a group or is solitary and lives alone. A primate's habitat determines the food to which they have access and the community of other species with whom they interact, including predators.

Haplorrhini

-The primate suborder that includes tarsiers, monkeys, apes, and humans. -Haplorrhines also evolved to have a fovea, a depression in the retina at the back of the eye containing concentrations of cells that allow us to see things very close up in great detail. -The heavier reliance on vision over olfaction is also reflected in the shorter snouts ending with the dry nose(no rhinarium) of haplorrhines. -Larger -more species that are folivorous and frugivorous, and fewer that are insectivorous. This dietary difference is reflected in the teeth of haplorrhines, which are broader with more surface area for chewing. -many members of this group show moderate to high sexual dimorphism in body size and canine size -Suborder Haplorrhini is divided into three infraorders: Tarsiiformes, which includes the tarsiers of Asia; Platyrrhini, which includes the New World monkeys of Central and South America; and Catarrhini, a group that includes the Old World monkeys and apes of Asia and Africa, as well as humans.

Streppsirrhines

-The strepsirrhines include the groups commonly called lemurs, lorises, and galagos. Strepsirrhines differ from haplorrhines in many ways, most of which involve retaining primitive traits from the last common ancestor of primates -The two derived traits are the grooming claw, which is on the second digit of each foot, and the tooth comb(or dental comb), located on the lower, front teeth -Compared to haplorrhines, strepsirrhines rely more on nonvisual senses. Strepsirrhines have longer snouts than haplorrhines and get their name because they all have wet noses (rhinariums) like cats and dogs. The long snout and rhinarium reflect strepsirrhines' greater reliance on olfaction relative to haplorrhines. -all have postorbital bars -All strepsirrhines have a tapetum lucidum, a reflective layer at the back of the eye that reflects light and thereby enhances the ability to see in low-light conditions. -more of them have a diet consisting of insects and fruit, with few taxa eating primarily leaves. -most strepsirrhines are good at leaping, with several taxa specialized for vertical clinging and leaping. -strepsirrhines can be found all across the Old World: in Asia, Africa, and on the island of Madagascar. -Strepsirrhini is divided into two groups: (1) the lemurs of Madagascar and (2) the lorises, pottos, and galagos of Africa and Asia.

Quadrupedal

-Using all four limbs to support the body during locomotion; the basic mammalian (and primate) form of locomotion. -- Arboreal (in trees) ◆ Forelimbs shorter - Most monkeys - Terrestrial ◆ Limbs approx. equal lengths - Most apes - Gorillas, bonobos, and chimps: Knuckle or Fist walking -Moving around on all fours -the most common form of locomotion among primates -Animals that move in this way usually have legs and arms that are about the same length and typically have a tail for balance. Arboreal quadrupeds usually have shorter arms and legs and longer tails, while terrestrial quadrupeds have longer arms and legs and, often, shorter tails.

Frugivores

-characterized by large incisors, bunodont molars, and digestive tracts that are intermediate in complexity between the other two dietary types.

Traditional Primate Classification: grades

-groupings that reflect levels of adaptation or overall similarity and not necessarily actual evolutionary relationships. An example of a grade would be placing orangutans, gorillas, bonobos, and chimpanzees into a group, and excluding humans. Grouping in this way is based on the superficial similarities of the apes in being large-bodied, having lots of body hair, living in tropical forests, using trees, and so on. -Traditionally, primates were classified based on grades into: • Prosimii (Prosimians): • Lorises • Lemurs • Tarsiers • Anthropoidea (Anthropoids): • Platyrrhines (NW monkeys) • Catarrhines (OW monkeys, apes, humans)

Folivores

-have broad molars with high, sharp cusps connected by shearing crests. These molar traits allow folivores to physically break down fibrous leaves when chewing. Folivores then have to chemically break down cellulose molecules into usable energy, so these animals need specialized digestive systems.

Parental Investment

-in many species, including primates, maternal behavior is not purely instinctual; it is dependent on social learning(behavior learned by observing and imitating others), as well. -although females invest more in offspring than males, there are some conditions under which males will invest. Male investment takes many forms, ranging from carrying or grooming infants to sharing food with them, to protecting them from infanticide(killing of infants of one 's own species) or predators, to simply tolerating their presence -Basic social unit among primates: Female and her infant(s) ◼ Males do not directly help in rearing offspring. Except in some species in which polyandry (one female, more than one male) or bonded pairs occur - Only when they know for sure they are the father?

Dietary plasticity

-organism's flexibility in adapting to diets from various environments -. The most common dietary types among primates are those whose diets consist primarily of fruit (frugivores), those who eat mostly insects (insectivores), and those who eat primarily leaves (folivores). Fewer primates are gummivores, who specialize in eating gums and saps

Conservation Strategies

-protected areas, community-based conservation, captive breeding -Establishment of national parks, nature reserves, wildlife sanctuaries • Reintroduction programs • Zoos, sanctuaries, breeding programs

Arboreal adaptation

-suite of physical traits that allow organisms to live in trees. -The hands and feet of different primates clearly show the opposable thumbs and big toes, pentadactyly, flattened nails, and tactile pads that are characteristic of our Order. Primates also differ from other animals in our hands and feet. The Order Primates is a largely arboreal taxonomic group, which means that most primates spend a significant amount of their time in trees. As a result, the hands and feet of primates have evolved to move around in a three-dimensional environment. Primates have the generalized trait of pentadactyly— possessing five digits (fingers and toes) on each limb. Many non-primates, like dogs and horses, have fewer digits because they are specialized for high-speed, terrestrial(on the ground) running.Pentadactyly is also a primitive trait, one that dates back to the earliest four-footed animals. Primates today have opposable thumbs and, except humans, opposable big toes Opposable thumbs/toes are a derived trait that appeared in the earliest primates about 55 million years ago

Social structure

-the composition, size, and sex ratio of a group of animals ◼ The results of natural selection in specific habitats ◼ Influences individual interactions and social relationships ◼ Primates among the most social of animals -social system describes the typical number of males and females of all age classes that live together.

Why Study Primates?

1) Our closest living relatives! 2) Models of human origins and behaviors. 3) Learn more about ourselves...plus, they are really cool

Factors influencing Social Structure

Activity Patterns • Nocturnal species tend to forage alone or in small groups (2-3 individuals) Human Activities • Virtually all nonhuman primate populations are impacted by human hunting and forest clearing • Disrupts and isolates groups, reduces numbers, reduces resource availability, and eventually can cause extinction

Semantic Vocal Communication

Alarm calls • In presence of predators • Vervet monkeys: • Distinct calls for specific predators, that cause different adaptive responses in receivers • E.g. aerial versus canine predator -Vervets clearly understand the meaning of each type of alarm call, as they respond appropriately even when they do not see the actual predator. Such semantic communication, which involves the systematic use of signals to refer to objects in the environment, was once believed to be unique to humans. It may be a precursor to the symbolic capacities of human language.

Life History Traits

Characteristics or developmental stages that influence reproduction rates ◼ Length of gestation, interbirth intervals, period of infant dependency, age at weaning or sexual maturity, and life expectancy

Culture and Social Learning

Cultural behavior is learned, passed from generation to generation ◼ Many cultural traditions have been observed in non-human primates ◼ Japan's macaques washing their potatoes before eating them ◼ Chimpanzees playing in water (they cannot swim, and are normally scared of water and avoid it, but somehow one specific population has learned to enjoy it and it has become a tradition within that specific group) ◼ Both, human children and young non-human primates acquire a tremendous amount of knowledge through learning ◼ Most primatologists agree that in its most basic sense, non-human primates have the ability to develop cultural traditions.

Dispersal

Dispersal (Leaving birth group after maturation to live solitary, with a different group, or to find mates outside natal group) ◼ Both, male and female dispersal found in primates ◼ Why? Lowers competition for mates and decreases likelihood for inbreeding -group-living species, one or both sexes must disperse at sexual maturity. Which sex disperses depends on the relative costs and benefits to each. In most primate species, males are the dispersing sex because the benefits of dispersal, including increased access to mates and reduced competition from other males, outweigh the costs -For most female primates, the opposite is true: they usually benefit from remaining philopatric, or in the group of their birth. This allows them to maintain strong social alliances so that they can compete successfully against other groups for food. -Members of both sexes may experience aggression from same-sex members of their chosen group because they are viewed as potential competitors. Aggression toward transferring individuals has been documented in multiple species, and aggression directed toward transferring males is almost universal and can be lethal.

Habitat Destruction

Effects are highly variable • Fragmentation (see image) affects movement of animals, predators, can cause inbreeding • Affects seed dispersal, health of forests -Recent analysis showed human demands for agricultural land threaten 76% of primate species, followed by demands for logging (60%) and livestock farming (31%). -Tropical rainforests are rich in biomass, land • Losing 2.4 acres per second • Only about 10% is legally preserved/protected

Factors influencing social structure

Factors influencing primate feeding habits: ◼ Body size: Larger animals better able to retain heat and overall energy requirements ◼ Basal Metabolic Rate (BMR) - Metabolism: Rate at which body uses energy to maintain bodily functions at a resting state ► Smaller animals - higher BMR ◼ Often rely on higher quality foods (e.g. insects) - more likely to live solitary, since high quality food sources are usually less abundant ► Larger animals - lower BMR ◼ More likely able to rely on less quality food sources (e.g. leaves) - which can often more abundant. More likely to be able to sustain larger groups sizes -Distribution of Resources ◼ Leaves abundant - support larger groups ◼ Fruits and nuts occur in clumps - better exploited by smaller groups ◼ Insects are harder to catch - and not easy to share Type and dispersal of predators ◼ Common predators: snakes, birds of prey, leopards, wild dogs, lions, and other primates ◼ Where predation pressure is high, large communities are advantageous

Limbs and Locomotion

Generalized, flexible limb structure - Wide range of limb movement, functions - Retain 5 digits with opposable thumb/big toe ◆High degree of prehensility: use hands and feet to grasp, manipulate objects, nails instead of claws ◆ Upright posture - Orthograde - When sitting, leaping, climbing ◆ some: occasional bipedal walking

Primate Reproductive Strategies

Goal: to produce and successfully rear to adulthood as many offspring as possible ◼ Female strategy: long birth intervals, high physiological investment, long dependent care ► Try to maximize the amount of resources available to her and her offspring. Common behaviors: aggressive defense of resources, or avoidance of other females (e.g. Chimpanzees) ◼ Male strategy: typically low investment in offspring, no assured fatherhood, typically do not invest in offspring, continuous sperm production in testes ► Try to secure as many mates and produce as much offspring as possible -Female strategies, on the one hand, focus on obtaining the food necessary to sustain a pregnancy and choosing the best male(s) to father offspring. Male strategies, on the other hand, focus on obtaining access to receptive females.

Distribution and Types of Sleeping Sites

Gorilla = only nonhuman primate that sleeps on the ground, all others sleep in trees ◼ Primate sleeping sites can be in trees or on cliff faces, their spacing can be related to social structure, predator avoidance, and availability of sleeping sites

Tactile Communication

Grooming (cleaning each other's fur) • Hygiene, pick out dirt and parasites • Reinforces relationship/conflict negotiation (If you help me, I will help you) • Solidarity • Mating • Giving and seeking assurance • Avoiding aggression -Huddling and sitting in contact • Manual inspection • Play -Physical contact is used to comfort and reassure, is part of courtship and mating, and is used to establish dominance and alliances. Grooming is an important and clearly enjoyable form of tactile communication for all primates -Not only does grooming serve to clean the skin and fur, removing parasites and debris, but it is an important affiliative(non-aggressive) behavior that helps reinforce social bonds, repair Relationships, and cement alliances.

Language

Humans capable of language displacement (use language to talk about things not happening momentarily or immediately in front of them), capacity to think symbolically ◼ Nonhuman animals not capable of communicating about external events, objects, or other animals -Some Apes can learn arbitrary symbols, but there is little evidence that they use acquired skills when communicating with each other. ◼ ALSO: Primate behavior in captivity can be very different from their behavior in the wild...

Olfactory, Gustatory Communication

In species with well-developed sense of smell • Mostly strepsirhines, some callitrichids and cebids • Scent spread by glands, urine, or feces • Active and passive signals • Least researched, difficult to measure and manipulate, no experimental studies Modes of communication: Main functions: ◼ Species recognition ◼ Claiming resources, marking home range ◼ Displaying individual characteristics, e.g. reproductive state, social rank, immunocompatibility ◼ Sometimes actively and strategically released, other times by-products of metabolic processes -All primates use scent to c ommunicate. Females secrete chemicals from their anogenital region ( the area of the anus and genitals) that provide males with information about their reproductive state. -Olfactory communication is particularly important for New World monkeys, lemurs, and lorises.

Senses and Brain

Increased reliance on vision - Frontation and convergence of orbits ◆ Binocular vision: overlapping visual field ◆ Stereoscopic (3D) vision: depth perception ◆ Color vision: almost all species ◆ Reduced olfaction ◆ Increased behavioral plasticity: ◆ Enlarged brain provides new ways to interact with environmental circumstances

Inventing

Inventing and using tools was long thought of as an exclusively human activity ◼ Requires foresight and planning ◼ Non-human primates use tools to open nuts (Capuchins), fish for termites (Chimpanzees), etc. ◼ There are regional variations in tool use = cultural variants ◼ Orangutan have been observed using natural remedies to cure themselves

Reproductive Strategies: R & K

K-selected: ◼ Producing only a few young in whom they invest increased parental care. R-selected: ◼ An adaptive strategy that emphasizes large numbers of offspring and reduced parental care, e.g. insects, most fishes, mice and rabbits.

Pet Trade

Lots of people keep primates as pets, it's a bad idea • For the rich, it's become a status symbol • Often primate parents are killed during capture • Risk of disease transmission • 80-90% of macaques carry Herpes B, deadly to humans, harmless in macaques -Less than 50% of US states ban private primate ownership -Primates have dominance hierarchies, can be aggressive • Removal of canines, other teeth and nails does not prevent accidents/attacks

Primate Social Behavior: Dominance Hierarchies

Many primate societies organized into Dominance Hierarchies (also called "Pecking orders") ◼ Individuals within a group impose a hierarchical order by establishing parameters of individual behavior ◼ Higher-ranking animals have greater access to preferred food and mating partners ◼ Hierarchies can exists within females or males ◼ Dominant hierarchies, when present, increase the amount of physical violence within a group -The ranked organization of individuals established by the outcome of aggressive-submissive interactions. -. A dominance hierarchy reflects the place of each individual in the group in comparison to others. An individual's place in the hierarchy, or " rank," determines their priority of access to resources. -Dominance in chimps: High-Ranking Females: ◼ Higher rates of infant survival ◼ Daughters mature faster ◼ Shorter interbirth intervals, more offspring High-Ranking Males: ◼ Better access to mates, food

Vocal communication

Most primates vocalize, main channel of communication • Vocal repertoires species-specific (develop under strict genetic control) • Territorial calls • Alarm calls • Contact calls • Social interaction vocalizations • Species recognition -Primates use sound to claim and maintain a territory, make contact with other group members, or to communicate danger or threats, among other things. Loud calls are designed to travel great distances and are use d in territorial defense by many primate species including indris, orangutans, gibbons, howler monkeys, and siamangs.

Different from human language?

No evidence of use of call combinations in generative and creative way to "make infinite use of finite means", no grammar. ◼ No social learning of language (instead, genetically programmed). ◼ Able to predict impact of signals on others (audience awareness), but only to some degree (understand physical response, not so much changes of mental state?). ◼ Not much evidence of intent.

Aggression and Territory Defense

Primate groups associated with a Home Range (permanent area they find food in) ◼ Portion of their home range containing the highest concentration and most reliable supplies of food and water = Core Area (which they will defended) Conflict/Aggression arises out of competition for resources, mates and food, and to establish or maintain hierarchies or core area • Females: attack in order to maintain pecking order, may cause weight loss and poor nutrition in lower-ranking females, lower reproductive success • Males: may result in injury and death

Disease

Primates can be exposed to human diseases and vice versa; can experience same disease in similar ways • Ebola • Fatal, liquefies organs • In gorillas, Ebola is 95% fatal • 2002 Republic of Congo, 95% of gorillas died • 2006 Gabon, 5000 gorillas died • Scientists estimate that 25% of the world's gorilla population has died from Ebola in the last 12 years -Disease is especially intertwined with climate change and has increasingly become a critical threat to primates. Shifting temperatures, unpredictable precipitation, crowding in fragmented habitats, and increased human contact can contribute to increased disease transmission among primates

Primate Communication

Purpose: Communicating biological and social needs • predator avoidance • interacting with others • maintaining cohesion during travel • bond with others • maintaining and establishing dominance hierarchy • persuade others to behave in a desired way -Olfactory, Gustatory (taste) • Tactile • Visual • Auditory • The type of communication used depends on proximity/group structure

The Primate Continuum

Seen as a continuum, many aspects of human behavior are but elaborate extensions of those of our hominin ancestors and close primate relatives ◼ Recognizing our primate heritage is a significant aspect in our exploration of how humans came to be and how we continue to adapt ◼ Many qualities that were thought of as exclusively human capabilities can be found among nonhuman primates as well...

Suborder primates

Strepsirhini (lemurs & lorises) - Haplorhini (tarsier, monkeys, apes, and humans)

Tarsiers

Tarsiers have a mix of traits that lead to debate about their classification. Some of their traits superficially resemble strepsirrhines, but they share many derived traits with haplorrhines.

Brain and Body Size

The relationship between body and brain size is the index of encephalization ◼ Modern human brain size is well beyond that expected for a primate of similar body weight ◼ Most primates are close to predicted ratios for brain-body size A central component of recent human evolution!

Parental investment

time and energy parents expend for their offspring's benefit

Maturation, Learning, Behavior

◆ Longer gestation - Less offspring, single birth norm ◆ Altricial young (born in an undeveloped state) - Long period of infant dependency ◆ Delayed maturation ◆ Strong mother-infant bond - Greater dependence on learned behavior ◆ Esp. in social groups