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Primate Definitions

These are selected primate related definitions. Click on the letter to move through the page more quickly.

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adaptation: "process whereby an organism changes in order to survive in its given environment; or, a specific new characteristic that enables survival." (Fleagle, 1999)

adaptive radiation: "a group of closely related organisms that have evolved morphological and behavioral features enabling them to exploit different ecological niches." (Fleagle, 1999)

age-graded group: "A social group with several adult females and several adult males who differ in social and reproductive status according to age. Thus, with time, an age-graded group can change from a one-male reproductive system to a multi-male system." (Fleagle, 1999)

age polyethism: "The regular changing of labor roles by members of a society as they age." (Wilson, 1975)

aggregation: "A group of individuals of the same species, comprised of more than just a mated pair or a family, gathered in the same place but not internally organized or engaged in cooperative behavior." (Wilson, 1975)

aggression: "A physical act or threat of action by one individual that reduces the freedom or genetic fitness of another." (Wilson, 1975)

agonistic: "Referring to any activity related to fighting, whether aggression or conciliation and retreat." (Wilson, 1975)

agonistic buffering: "The use of infants by adults to inhibit aggression by other adults, reported among male macaques and a few other monkeys." (Wilson, 1975)

agouti: "A fur color in which each hair has alternating light and dark bands, giving the fur a streaked appearance." (Rowe, 1996)

alarm-defense system: "Defensive behavior that also functions as an alarm signaling device within the colony. Examples include the use by certain ant species of chemical defensive secretions that double as alarm pheromones." (Wilson, 1975)

alarm phermones: "A chemical substance exchanged among members of the same species that induces a state of alertness or alarm in the face of a common threat." (Wilson, 1975)

allogrooming: "Grooming directed at another individual, as opposed to self-grooming, which is directed at one's own body." (Wilson, 1975)

allomone: "A chemical substance released by one species that serves as a communicative signal to another species." (Wilson, 1975)

alloparent: "An individual that assists the parents in care of the young." (Wilson, 1975)

alloparental care: "The assistance by individuals other than the parents in the care of offspring." (Wilson, 1975)

allopatry: "the absence of overlap in the geographical range of two species or populations." (Fleagle, 1999)

alpha: "Referring to the highest-ranking individual within a dominance hierarchy." (Wilson, 1975)

altricial: "Pertaining to young animals that are helpless for a substantial period following birth." (Wilson, 1975)

altruism: "Self-destructive behavior performed for the benefit of others." (Wilson, 1975)

analogue: "Referring to structures, physiological processes, or behaviors that are similar owing to convergent evolution as opposed to common ancestry; hence, displaying analogy." (Wilson, 1975)

analogy: "A resemblance in function, and often in appearance also, between two structures, physiological processes, or behaviors that is due to evolution rather than to common ancestry." (Wilson, 1975)

antisocial factor: "Any selection pressure that tends to inhibit or to reverse social evolution." (Wilson, 1975)

aposematism: "The advertisement by dangerous animals of their identity. Thus the most venomous wasps, coral fishes, and snakes are also often the most brightly colored." (Wilson, 1975)

arboreal: "Living in trees." (Fleagle, 1988)

arboreal quadrupedalism: "Mode of locomotion in which the animal moves along the horizontal branches with a regular gait pattern involving all four limbs." (Fleagle, 1988)

autocatalysis: "Any process the rate of which is increased by its own products. Thus autocatalytic reactions, fed by positive feedback, tend to accelerate until the ingredients are exhausted or some external constraint is imposed." (Wilson, 1975)

automimicry: "The imitation by one sex or life stage of communication in another sex or life stage of the same species. An example is the imitation by the males of some monkey species of female sexual signals, which they appear to employ in appeasement rituals." (Wilson, 1975)

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baculum: "The bone present in the penis of most mammals." (Estes, 1991)

behavioral biology: "The scientific study of all aspects of behavior, including neurophysiology, ethology, comparative psychology, sociobiology, and behavioral ecology." (Wilson, 1975)

behavioral scaling: "The range of forms and intensities of a behavior that can be expressed in an adaptive fashion by the same society or individual organism." (Wilson, 1975)

bilophodonty: "a condition of the molar teeth in which the mesial and distal pairs of cusps form ridges or lophs." (Fleagle, 1999).

binocular vision: "The visual field within view of both eyes; the frontally placed eyes of cats and primates have most overlap and best depth perception." (Estes, 1991)

bipedalism: "Mode of locomotion using only the hindlimbs, usually alternately rather than together." (Fleagle, 1988)

bit: "The basic quantitative unit of information; specifically, the amount of information required to control, without error, which of two equiprobable alternates is to be chosen by the receiver." (Wilson, 1975)

bonding: "Any close relationship formed between two or more individuals." (Wilson, 1975)

brachiation: "Arboreal locomotion in which the animal progresses below branches by using only the forelimbs." (Fleagle, 1988)

brood: "Any young animals that are being cared for by adults." (Wilson, 1975)

browser: "An ungulate that feeds mainly on plants other than grasses, especially foliage." (Estes, 1991)

bunodont: "(teeth) have low, rounded cusps." (Fleagle, 1999)

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caniniform: "shaped like a canine." (Conroy, 1990)

canopy: "A layer of forest foliage that is laterally continuous and usually distinct vertically from other layers. A tropical forest often has one or more distinct canopies." (Fleagle, 1988)

cantilevering: "Springing out from a branch to catch prey with the hands while the hind legs hold on to the branch." (Rowe, 1996)

casual society (or group): "A temporary group formed by individuals within a society. The casual society is unstable, being open to new members and losing old ones at a high rate. Examples include feeding groups of monkeys within a troop and groups of playing children." (Wilson, 1975)

cathemeral: "Active intermittently throughout the twenty-four-hour day rather than active only during the day (diurnal) or only during the night (nocturnal)." (Fleagle, 1988)

cecum: "A blind sac situated at the junction of the small and large intestine, in which digestion of cellulose by bacteria occurs in nonruminants." (Estes, 1991)

choanae: "Internal nares." (Groves, 2001)

chorus: "A group of calling anurans (frogs or toads) or insects." (Wilson, 1975)

circadian rhythm: "A rhythm in behavior, metabolism, or some other activity that recurs about every 24 hours." (Wilson, 1975)

commensalism: "Symbiosis in which members of one species are benefited while those of the other species are neither benefited nor harmed." (Wilson, 1975)

communal: "Applied to the condition or to the group showing it in which members of the same generation cooperate in nest building but not in brood care." (Wilson, 1975)

communication: "Action on the part of one organism (or cell) that alters the probability pattern of behavior in another organism (or cell) in an adaptive fashion." (Wilson, 1975)

competition: "The active demand by two or more organisms (or two or more species) for a common resource." (Wilson, 1975)

composite signal: "A signal composed of two or more simpler signals." (Wilson, 1975)

coniferous forest: "Cone-bearing, usually evergreen trees, such as cedars, pines, and firs." (Rowe, 1996)

consortship: "Exclusive association with a female maintained by a male during the period of estrus to keep any other male from mating with her." (Estes, 1991)

conspecific: "Belonging to the same species." (Wilson, 1975)

contagious behavior: "An action that stimulates other animals to follow suit." (Estes, 1991)

control: "According to strict sociobiological usage, particularly in primate studies, control is intervention by one or more individuals of the group." (Wilson, 1975)

conventional behavior: "According to the hypothesis proposed by V.C. Wynne-Edwards, any behavior by which members of a population reveal their presence and allow others to assess the density of the population. A more elaborate form of such behavior is referred to as an epideictic display." (Wilson, 1975)

core area: "The area of heaviest regular use within the home range." (Wilson, 1975)

cranial capacity: "The volume of the brain, usually determined by measuring the volume of the inside of the neurocranium." (Fleagle, 1999).

crenulation: "wrinkled surface of the tooth enamel of some primates." (Conroy, 1990)

crepuscular: "Active primarily during the hours around dawn and dusk." (Fleagle, 1988)

cryptic: "Hidden; not normally visible." (Fleagle, 1999).

cursorial: "refers to a type of terrestrial locomotion characterized by fast running." (Conroy, 1990)

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dear enemy phenomenon: "The recognition of territorial neighbors as individuals, with the result that aggressive interactions are kept at a minimum. The more intense forms of aggression are reserved for strangers." (Wilson, 1975)

deciduous dentition: "The milk teeth or first set of teeth in the mammalian jaw. The deciduous dentition is replaced by the permanent dentition." (Fleagle, 1999).

demographic society: "A society that is stable enough through time, usually owing to its being relatively closed to newcomers, for the demographic processes of birth and death to play a significant role in its composition." (Wilson, 1975)

dental formula: "A notation of the number of incisors, canines, premolars, and molars in the upper and lower dentition of a species. In humans, the adult dental formula is 2:1:2:3/2:1:2:3." (Fleagle, 1999).

derived feature: "A specialized morphological (or behavioral) characteristic that departs from the condition found in the ancestors of a species or group of species." (Fleagle, 1999).

dialect: "In the study of animal behavior, local geographic variants of bird songs, honeybee waggle dances, and other displays used in communication." (Wilson, 1975)

diastema: "space or gap between adjacent teeth in the dental row." (Conroy, 1990)

digitigrade: "Animals that walk on their digits rather than the whole foot." (Estes, 1991)

dimorphism: "In caste systems, the existence in the same colony of two different forms, including two size classes, not connected by intermediates." (Wilson, 1975)

dipterocarp forest: "Southeast Asian forest with a large portion of tall trees of the family Dipterocarpaceae." (Rowe, 1996)

disassortative mating: "The nonrandom pairing of individuals that differ from each other in one or more traits." (Wilson, 1975)

discrete signal: "A signal used in communication that is turned either on or off, without significant intermediate gradations." (Wilson, 1975)

dispersal: "Movement of animals away from their natal home range, typically before maturity." (Estes, 1991)

displacement activity: "The performance of a behavioral act, usually in conditions of frustration or indecision, that is not directly relevant to the situation at hand." (Wilson, 1975)

display: "A behavior pattern that has been modified in the course of evolution to convey information. A display is a special kind of signal, which in turn is broadly defined as any behavior that conveys information regardless of whether it serves other functions." (Wilson, 1975)

distraction display: "A performance by a parent that draws the attention of predators away from its offspring." (Wilson, 1975)

diurnal: "Active during the day." (Rowe, 1996)

dominance hierarchy: "The physical domination of some members of a group by other members, in relatively orderly and log-lasting patterns. Except for the highest- and lowest-ranking individuals, a given member dominates one or more of its companions and is dominated in turn by one or more of the others. The hierarchy is initiated and sustained by hostile behavior, albeit sometimes of a subtle and indirect nature." (Wilson, 1975)

dorsal: "Toward the back side of the body; the opposite of ventral." (Fleagle, 1999).

duetting: "The rapid and precise exchange of notes between two individuals, especially mated birds." (Wilson, 1975)

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ecology: "The scientific study of the interaction of organisms with their environment, including both the physical environment and the other organisms that live in it." (Wilson, 1975)

ecosystem: "All of the organisms of a particular habitat, such as a lake or forest, together with the physical environment in which they live." (Wilson, 1975)

ecotone: "The transition zone or 'edge' between two different types of habitat." (Estes, 1991)

emergent trees: "Trees that grow above the top of the canopy." (Rowe, 1996)

enculturation: "The transmission of a particular culture, especially to the young members of the society." (Wilson, 1975)

endemic: "Referring to a species that is native to a particular place and found nowhere else." (Wilson, 1975)

epideictic display: "In theory at least, a display by which members of a population reveal their presence and allow others to assess the density of the population. An extreme form of 'conventional behavior' as postulated by V.C. Wynne-Edwards." (Wilson, 1975)

epigamic: "Any trait related to courtship and sex other than the essential organs and behavior of copulation." (Wilson, 1975)

estrus: "The period of heat, or maximum sexual receptivity, in the female." (Wilson, 1975)

ethmoid bone: "small bone in the skull that contributes to the medial orbital wall in some primates and also forms a small portion of the floor of the braincase under the frontal bones." (Conroy, 1990)

ethocline: "A series of different behaviors observed among related species and interpreted to represent stages in an evolutionary trend." (Wilson, 1975)

ethology: "The study of whole patterns of animal behavior in natural environments, stressing the analysis of adaptation and the evolution of the patterns." (Wilson, 1975)

extant: "Living, as opposed to extinct." (Fleagle, 1999).

exudate: "A substance, such as gum, sap, or resin, which flows from the vascular system of a plant." (Fleagle, 1988)

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floaters: "Individuals unable to claim a territory and hence forced to wander through less suitable surrounding areas." (Wilson, 1975)

fission-fusion society: " A type of social organization in which individuals regularly form small subgroups for foraging but from time to time also join together in larger groups; the variation in grouping usually depends on the type of food." (Fleagle, 1988)

folivore: "An animal that eats leaves." (Wilson, 1975)

foraging strategy: "The behavioral adaptations of a species related to its acquisition of food items." (Fleagle, 1999).

foramen magnum: "large hole in the base of the skull through which the spinal cord passes, joining the base of the brain." (Conroy, 1990)

fraser darling effect: "The stimulation of reproductive activity by the presence and activity of other members of the species in addition to the mating pair." (Wilson, 1975)

frenulum: "small fold of skin immobilizing the upper lip; present in all extant strepsirhines but reduced or absent in extant haplorhines." (Conroy, 1990)

frugivore: "An animal that eats fruit." (Wilson, 1975)

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gallery forest: "A forest along a river or stream." (Fleagle, 1988)

gecker: "Cackling sound of distress/protest made by fearful monkey, mongooses, jackals, etc." (Estes, 1991)

gestation: "The period between conception and birth."

genetic drift: "Change in allele frequencies in a population due to chance rather than selection." (Fleagle, 1999).

glabella "A forward protrusion in the midline between the two supraorbital bars." (Groves, 2001)

gracile: "describes any slender, lightly built body or body part." (Conroy, 1990)

graded signal: "A signal that varies in intensity or frequency or both, thereby transmitting quantitative information about such variables as mood of the sender, distance of the target, and so forth." (Wilson, 1975)

graminivore: " An animal that eats primarily grains; often also used to describe an animal that eats seeds." (Fleagle, 1988)

grazer: "A herbivore that eats mainly grass." (Estes, 1991)

grooming: "The cleaning of the body surface by licking, nibbling, picking with the fingers, or other kinds of manipulation." (Wilson, 1975)

group: "Any set of organisms, belonging to the same species, that remain together for a period of time while interacting with one another to a distinctly greater degree than with other conspecific organisms." (Wilson, 1975)

group defense: "Cooperative defense (usually against predators) by two or more individuals, as distinct from the more common defense by just one individual." (Estes, 1991)

group effect: "An alteration in behavior or physiology within a species brought about by signals that are directed in neither space nor time. A simple example is social facilitation, in which there is an increase of an activity merely from the sight or sound (or other form of stimulation) coming from other individuals engaged in the same activity." (Wilson, 1975)

group predation: "The hunting and retrieving of living prey by groups of cooperating animals. This behavior pattern is developed, for example, in army ants and wolves." (Wilson, 1975)

gummivore: "an animal that eats exudates-gum, saps, or resin." (Fleagle, 1988)

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habitat: "The organisms and physical environment in a particular place." (Wilson, 1975)

harem: "A group of females guarded by a male, who prevents other males from mating with them." (Wilson, 1975)

herd: "A social group consisting of at least two same-sex adults; generally applied to gregarious ungulates." (Estes, 1991)

hierarchy: "In general, a system of two or more levels of units, the higher levels controlling at least to some extent the activities of the lower levels in order to integrate the group as a whole. In dominance systems within societies, a hierarchy is the sequence of dominant and dominated individuals." (Wilson, 1975)

hindgut fermenter: "Nonruminant herbivore or omnivore, in which breakdown of cellulose occurs in the cecum and large intestine." (Estes, 1991)

home range: "The area that an animal learns thoroughly and patrols regularly. The home range may or may not be defended; those portions that are defended constitute the territory." (Wilson, 1975)

homologue: "Referring to a structure, physiological process, or behavior that is similar to another owing to common ancestry; hence, displaying homology." (Wilson, 1975)

homology: "A similarity between two structures that is due to inheritance from a common ancestor." (Wilson, 1975)

honing facet: "surface on the anterior portion of the anterior lower premolar (a sectorial tooth) used to sharpen the posterior edge of the upper canine when the two teeth come into contact." (Conroy, 1990)

hyoid bone: "A bone or bone complex in the throat that supports the larynx and trachea." (Rowe, 1996)

hypocone: "cusp on the posterior lingual surface of the upper molars." (Conroy, 1990)

hypoconid: "cusp on the lateral rim of the talonid of lower molars." (Conroy, 1990)

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igapo: "Forest in a black-water river basin that floods seasonally." (Rowe, 1996)

imitation: "The copying of a novel or otherwise improbable act." (Wilson, 1975)

incisiform: "shaped like an incisor." (Conroy, 1990)

indirect role: "A behavior or set of behaviors that benefits only the subgroups that display it and is neutral or even destructive to other subgroups of the society." (Wilson, 1975)

individual distance: "The fixed minimal distance an animal attempts to keep between itself and other members of the species." (Wilson, 1975)

infanticide: "The killing of infants." (Fleagle, 1988)

infraorbital foramen: "external opening of the infraorbital canal on the anterior surface of the maxilla for passage of blood vessels and nerves to the lower surface." (Conroy, 1990)

instinct: "Behavior that is highly stereotyped, more complex than the simplest reflexes, and usually directed at particular objects in the environment. Learning may or may not be involved in the development of instinctive behavior; the important point is that the behavior develops toward a narrow, predictable end product." (Wilson, 1975)

intention movement: "The preparatory motions that an animal goes through prior to a complete behavioral response; for example, the crouch before the leap, the snarl before the bite, and so forth." (Wilson, 1975)

interorbital distance: "distance between the orbits measured at their medial margins." (Conroy, 1990)

ischial callosities: "The two pads on the rump, upon which Old World monkeys and gibbons sit." (Rowe, 1996)

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Jarmin-Bell principle: "rule relating body size of mammals to the nutritional quality of the foods they eat: small mammals eat high-quality (high-energy), quickly digested foods such as insects, while larger mammals, needing relatively fewer calories per unit of body weight, can subsist on more low-quality, harder-to-digest foods processed in bulk, such as leaves." (Conroy, 1990)

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K selection: "Selection favoring superiority in stable, predictable environments in which rapid population growth is unimportant." (Wilson, 1975)

Kay's threshold: "approximate body weight (around 500 g) that separates primarily insectivorous from noninsectivorous primates." (Conroy, 1990)

keystone resources: "Critical elements in a species' ecology that limits its population size and distribution." (Fleagle, 1999).

kinopsis: "Attraction to other members of a society by the sight of their movement alone." (Wilson, 1975)

knuckle-walking: "A type of quadrupedal walking, used by chimpanzees and gorillas, in which the upper body is supported by he dorsal surface of the middle phalanges of the hands." (Fleagle, 1988)

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lek: "An area used consistently for communal courtship displays." (Wilson, 1975)

lingual: "toward the tongue." (Conroy, 1990)

lowland forest: "Forest below 1 kilometer (3281) feet in altitude. Lowland forests often have the most biodiversity." (Rowe, 1996)

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mandibular body: "horizontal portion of the mandible; also called the horizontal ramus of the mandible." (Conroy, 1990)

mandibular symphysis: "The joint between the right and left halves of the mandible. In humans and other higher primates, this joint is fused." (Fleagle, 1999).

mass communication: "The transfer among groups of individuals of information of a kind that cannot be transmitted from a single individual to another. Examples include the spatial organization of army ant raids, the regulation of numbers of worker ants on odor trails, and certain aspects of the thermoregulation of nests." (Wilson, 1975)

matrifocal: "Pertaining to a society in which most of the activities and personal relationships are centered on the mothers." (Wilson, 1975)

matrilineal: "Passed from the mother to her offspring, as for example access to a territory or status within a dominance system." (Wilson, 1975)

maxillary sinus: "air space within the maxillary bone." (Conroy, 1990)

mesial: "toward the anterior side of a molar or premolar tooth or to the side of an incisor tooth nearest the midline of the jaw." (Conroy, 1990)

mesopterygoid fossa: "The fossa bounded by the pterygoid plates, continuous with the nares anteriorly." (Groves, 2001)

metacommunication: "Communication about communication. A metacommunicative signal imparts information about how other signals should be interpreted. Thus a play invitation signal indicates that subsequent threat displays should be taken as play and not as serous hostility." (Wilson, 1975)

metacone: "one of three primary cusps on the crown of upper molars; found on the posterior buccal (outer back) corner of the tooth." (Conroy, 1990)

metaconid: "one of three main cusps on the trigonid (anterior triangular portion) of lower molars; found on the distal lingual (inner back) corner of the trigonid." (Conroy, 1990)

metapopulation: "A set of populations of organisms belonging to the same species and existing at the same time; by definition each population occupies a different area." (Wilson, 1975)

mobbing: "The joint assault on a predator too formidable to be handled by a single individual in an attempt to disable it or at least to drive it from the vicinity." (Wilson, 1975)

molariform: "molarlike in form and function." (Conroy, 1990)

monogamy: "The condition in which one male and one female join to rear at least a single brood." (Wilson, 1975)

monogyny: "In animals generally, the tendency of each male to mate with only a single female." (Wilson, 1975)

montane forest: "Forest found at higher altitudes and characterized by shorter trees covered with mosses and lichens." (Rowe, 1996)

morphology: "The shape of anatomical structures." (Fleagle, 1999).

multi-male group: "A group of animals in which several adult males and several adult females are reproductively active." (Fleagle, 1988)

multiplier effect: "In sociobiology, the amplification of the effects of evolutionary change in behavior when the behavior is incorporated into the mechanisms of social organization." (Wilson, 1975)

mutualism: "Symbiosis in which both species benefit from the association." (Wilson, 1975)

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nectivore: "An animal that eats nectar." (Fleagle, 1999).

neoteny: "The retention of the features of a juvenile animal of one species in the adult form of a different species." (Fleagle, 1999).

neotropics "The tropical regions of North America, Central America, and South America." (Fleagle, 1999).

neurocranium: "portion of the skull enclosing the brain, as distinct from the facial bones and the basicranium." (Conroy, 1990)

neurophysiology: "The scientific study of the nervous system, especially the physiological processes by which it functions." (Wilson, 1975)

niche: "The range of each environmental variable, such as temperature, humidity, and food items, within which a species can exist and reproduce. The preferred niche is the one in which the species performs best, and the realized niche is the one in which it actually comes to live in a particular environment." (Wilson, 1975)

nuchal crest: "bony shelf on the back of the skull for the attachment of powerful neck muscles." (Conroy, 1990)

noyau: "A social structure in which a male's territory overlaps the smaller territories of several females; found in several nocturnal primates." (Rowe, 1996)

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observational learning: "Unrewarded learning that occurs when one animal watches the activities of another. Same as empathic learning." (Wilson, 1975)

omnivore: "An animal that eats both animal and vegetable materials." (Wilson, 1975)

one-male group: "A social group containing several reproductively active females but only one reproductively active male." (Fleagle, 1988)

ontogeny: "Individual development, from conception to maturity." (Groves, 2001)

opportunistic species: "Species specialized to exploit newly opened habitats. Such species usually are able to disperse for long distances and to reproduce rapidly; in other words they are r selected." (Wilson, 1975)

outcrossing: "The pairing of unrelated individuals." (Wilson, 1975)

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panmictic: "Referring to a population in which mating is completely random; a panmictic population is often referred to as a deme." (Wilson, 1975)

paracone: "one of three primary cusps on the crowns of primate upper molars; found on the mesial buccal (outer front) corner of the tooth." (Conroy, 1990)

paraconid: "cusp on the mesial lingual surface of the lower molars." (Conroy, 1990)

parallel evolution: "Independent evolution of similar (and homologous) morphological features in separate lineages." (Fleagle, 1999).

parasitism: "Symbiosis in which members of one species exist at the expense of members of another species, usually without going so far as to cause their deaths." (Wilson, 1975)

parental investment: "Any behavior toward offspring that increases the chances of the offspring's survival at the cost of the parent's ability to invest in other offspring." (Wilson, 1975)

perineum: "The area that includes the anus and external genitalia." (Estes, 1991)

pheromone: "A chemical substance, usually a glandular secretion, that is used in communication within a species. One individual releases the material as a signal and another responds after tasting or smelling it." (Wilson, 1975)

philopatry: "The tendency of animals to remain at certain places at least to return to them for feeding and resting." (Wilson, 1975)

philtrum: "vertical cleft in the rhinarium of extant strepsirhines; not present in haplorhines." (Conroy, 1990)

phylogeny: "Evolutionary history." (Groves, 2001)

polyandry: "The acquisition by a female of more than one male as a mate." (Wilson, 1975)

plantigrade: "Flat-footed: applies to animals which walk on the whole foot, e.g. elephants, hyraxes, and man." (Estes, 1991)

polygamy: "The acquisition, as part of the normal life cycle, of more than one mate." (Wilson, 1975)

polygyny: "In animals generally, the tendency of each male to mate with two or more females." (Wilson, 1975)

population: "A set of organisms belonging to the same species and occupying a clearly delimited space at the same time. A group of populations of the same species, each of which by definition occupies a different area, is sometimes called a metapopulation." (Wilson, 1975)

precocial: "Referring to young animals who are able to move about and forage at a very early age; especially in birds." (Wilson, 1975)

predator: "Any organism that kills and eats other organisms." (Wilson, 1975)

prehallux: "small sesamoid (accessory) bone sometimes occurring in the tarsometatarsal joint of the hallux." (Conroy, 1990)

prehensile: "Capable of grasping; for example, the prehensile tail of some platyrrhine monkeys." (Fleagle, 1988)

presenting: "The act of directing the hindquarters toward another individual, either in sexual solicitation or as a gesture of appeasement derived from sexual presenting." (Estes, 1991)

presocial: "Especially in insects, applied to the condition or to the group possessing it in which individuals display some degree of social behavior short of eusociality. Presocial species are either subsocial, i.e., the parents care for their own nymphs and larvae; or else parasocial, i.e., one or two of the following three traits are shown: cooperation in care of young, reproductive division of labor, and overlap of generations of life stages that contribute to colony labor." (Wilson, 1975)

primary rainforest: "Rainforest characterized by the later stages of the vegetational succession cycle." (Fleagle, 1988)

primer pheromone: "A pheromone (chemical signal) that acts to alter the physiology of the receiving organism in some way and eventually causes the organism to respond differently." (Wilson, 1975)

prognathism: "Prominence of the snout." (Fleagle, 1999).

prosthion: "The most anterior point on the cranium, between the upper central incisor alveoli." (Groves, 2001)

protocone: "one of three main cusps on the crowns of primate upper molars; found on the lingual side of the tooth." (Conroy, 1990)

protoconid: "one of three main cusps on the trigonid (anterior triangular portion) of lower molars; found on the buccal side of the tooth." (Conroy, 1990)

proximal: "closer to any particular point of reference." (Conroy, 1990)

pterygoid plates: "The bony plates behind the choanae; usually two pairs, internal and external." (Groves, 2001)

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quadritubercular: "having four cusps; refers to a four-sided (squarish) molar tooth." (Conroy, 1990)

quasisocial: "Applied to the condition or to the group showing it in which members of the same generation use the same composite nest and cooperate in brood care." (Wilson, 1975)

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r selection: "Selection favoring rapid rates of population increase, especially prominent in species that specialize in colonizing short-lived environments or undergo large fluctuations in population size." (Wilson, 1975)

rank order: "A hierarchical arrangement of the individuals in a group." (Estes, 1991)

reciprocal altruism: "The trading of altruistic acts by individuals at different times." (Wilson, 1975)

redirected activity: "The direction of some behavior, such as an act of aggression, away from the primary target and toward another, less appropriate object." (Wilson, 1975)

releaser: "A sign stimulus used in communication. Often the term is used broadly to mean any sign stimulus." (Wilson, 1975)

releaser pheromone: "A pheromone (chemical signal) that is quickly perceived and causes a more or less immediate response." (Wilson, 1975)

ritualization: "The evolutionary modification of a behavior pattern that turns it into a signal used in communication or at least improves its efficiency as a signal." (Wilson, 1975)

robust: "describes any large, or heavily built body part." (Conroy, 1990)

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sagittal crest: "bony crest running along the midline of the skull for attachment of enlarged temporalis muscles." (Conroy, 1990)

savanna: "Open, flat tropical grassland with varying amounts of trees and seasonal rainfall." (Rowe, 1996)

scent mark: "An olfactory message communicated by rubbing glandular secretions or leaving urine or feces at a specific site." (Rowe, 1996)

schizodactyly: "Grasping between the second and third digits of the hand rather than between the pollex (thumb) and second digit." (Fleagle, 1999).

sclerocarpic frugivore: "An animal that eats hard-shelled fruits and seeds as a major percentage of its diet." (Rowe, 1996)

secondary rainforest: " Rainforest characterized by immature stages of the succession cycle, commonly found on the edges of forests, along rivers, and around tree falls." (Fleagle, 1988)

sectorial tooth: "tooth in the lower jaw (usually the anterior premolar) with a honing facet for sharpening the upper canine during occlusion." (Conroy, 1990)

selfishness: "In the strict usage of sociobiology, behavior that benefits the individual in terms of genetic fitness at the expense of the genetic fitness of other members of the same species." (Wilson, 1975)

semiotics: "The scientific study of communication." (Wilson, 1975)

sexual dimorphism: "Any consistent difference between males and females beyond the basic functional portions of the sex organs." (Wilson, 1975)

sexual skin: "The external genitalia and surrounding skin in female primates, which in many species varies in color and size with reproductive condition, being most colorful and swollen at the height of estrus." (Estes, 1991)

sexual swelling: "The swelling of sexual skin during the primate menstrual cycle, which reaches maximum inflation at estrus, then deflates, to begin again as the next ovarian follicle matures." (Estes, 1991)

sign stimulus: "The single stimulus, or one out of a very few such crucial stimuli, by which an animal distinguishes key objects such as enemies, potential mates, and suitable nesting places." (Wilson, 1975)

signal: "In sociobiology, any behavior that conveys information from one individual to another, regardless of whether it serves other functions as well." (Wilson, 1975)

social drift: "Random divergence in the behavior and mode of organization of societies." (Wilson, 1975)

social facilitation: "An ordinary pattern of behavior that is initiated or increased in pace or frequency by the presence or actions of another animal." (Wilson, 1975)

social homeostasis: "The maintenance of steady states at the level of the society either by control of the nest microclimate or by the regulation of the population density, behavior, and physiology of the group members as a whole." (Wilson, 1975)

social parasitism" "The coexistence of two species of animals, of which one is parasitically dependent on the societies of the other." (Wilson, 1975)

sociality: "The combined properties and processes of social existence." (Wilson, 1975)

socialization: "The total modification of behavior in an individual due to its interaction with other members of the society, including its parents." (Wilson, 1975)

society: "A group of individuals belonging to the same species and organized in a cooperative manner. The diagnostic criterion is reciprocal communication of a cooperative nature, extending beyond mere sexual activity." (Wilson, 1975)

sociobiology: "The systematic study of the biological basis of all social behavior." (Wilson, 1975)

sociocline: "A series of different social organizations observed among related species and interpreted to represent stages in an evolutionary trend." (Wilson, 1975)

sociogram: "The full description, taking the form of a catalog, of all the social behaviors of a species." (Wilson, 1975)

song: "In the study of animal behavior, any elaborate vocal signal." (Wilson, 1975)

spite: "In the strict terminology of evolutionary biology, behavior that lowers the genetic fitness of both the perpetrator and the individual toward which the behavior is directed." (Wilson, 1975)

stable age distribution: "The condition in which the proportions of individuals belonging to different age groups remain constant for generation after generation." (Wilson, 1975)

subspecies: "A geographic segment of a species, distinguishable from other such segments by strong gene frequency differences (traditionally, 75% of individuals are different from members of all other subspecies)." (Groves, 2001)

surface pheromone: "A pheromone with an active space restricted so close to the body of the sending organism that direct contact, or something approaching it, must be made with the body in order to perceive the pheromone. Examples include the colony odors of many species of social insects." (Wilson, 1975)

suspensory behavior: "Locomotor and postural habits characterized by hanging or suspension of the body below or among branches rather than walking, running, or sitting on top of branches." (Fleagle, 1988)

symbiont: "An organism that lives in symbiosis with another species." (Wilson, 1975)

symbiosis: "The intimate, relatively protracted, and dependent relationship of members of one species with those of another. The three principal kinds of symbiosis are commensalism, mutualism, and parasitism." (Wilson, 1975)

sympatry: "Overlap in the geographical range of two species or populations." (Fleagle, 1999).

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talonid: "posterior heellike portion of lower molars." (Conroy, 1990)

taxis: "The movement of an organism in a fixed direction with reference to a single stimulus. Thus, a phototaxis is a movement toward or away from a light, a geotaxis is a movement up of down in response to gravity, and so forth." (Wilson, 1975)

taxonomy: "The classification of organisms." (Groves, 2001)

terra firma forest: "Lowland forest that is not flooded seasonally." (Rowe, 1996)

terrestrial: "On the ground." (Fleagle, 1999).

terrestrial quadrupedalism: "Four-limbed locomotion on the ground." (Fleagle, 1988)

territory: "An area occupied more or less exclusively by an animal or group of animals by means of repulsion through overt defense or advertisement." (Wilson, 1975)

tooth comb: "A formation of the lower incisors into a comblike structure for grooming." (Fleagle, 1999).

total range: "The entire area covered by an individual in its lifetime." (Wilson, 1975)

tradition: "A specific form of behavior, or a particular site used for breeding or some other function, passed from one generation to the next by learning." (Wilson, 1975)

trigone: "portion of the upper molars formed from the three main cusps: protocone, metacone, and paracone." (Conroy, 1990)

trigonid: "anterior triangular portion of the lower molars; contains the paraconid (when present), protoconid, and metaconid." (Conroy, 1990)

tritubercular: "having three cusps; refers to a triangular-shaped tooth." (Conroy, 1990)

trophobiosis: "The relationship in which ants receive honeydew from aphids and other homopterans, or the caterpillars of certain lycaenid and riodinid butterflies, and provide these insects with protection in return. The insects providing the honeydew are referred to as trophobionts." (Wilson, 1975)

type locality: "The locality at which a type specimen was obtained." (Groves, 2001)

type species: "The species on which a genus (or subgenus) was orginally founded and to which the name is forever indissolubly attached." (Groves, 2001)

type specimen: "The specimen on the evidence of which a species or subspecies was originally named and to which the name is forever indissolubly attached." (Groves, 2001)

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Umwelt: "A German expression (loosely translated, 'the world around me') used to indicate the total sensory input of an animal. Each species, including man, has its own distinctive Umwelt." (Wilson, 1975)

understory: "The lowest forest level, between the ground and 10 meters (33 feet)." (Rowe, 1996)

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vertical clinging and leaping: " A type of locomotion and posture in which animals cling to vertical supports and move by leaping between these vertical supports." (Fleagle, 1988)

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zoology: "The scientific study of animals." (Wilson, 1975)

zoosemiotics: "The scientific study of animal communication." (Wilson, 1975)

zygomatic-arch: "bony arch on the lateral part of the skull formed by projections of the zygomatic bone and the temporal bone for attachment of the masseter muscle." (Conroy, 1990)

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Conroy, G.C. 1990. Primate Evolution. W.W. Norton and Co.: New York.

Estes, R.D. 1991. The Behavior Guide to African Mammals. University of California Press: Berkeley.

Fleagle, J.G. 1988. Primate Adaptation and Evolution. Academic Press: New York.

Fleagle, J.G. 1999. Primate Adaptation and Evolution. Academic Press: San Diego.

Groves, C. 2001. Primate Taxonomy. Smithsonian Institution Press: Washington, DC.

Rowe, N. 1996. The Pictorial Guide to the Living Primates. Pogonias Press: East Hampton, New York.

Wilson, E.O. 1975. Sociobiology: The New Synthesis. Harvard University Press: Cambridge.

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