Glossary of Terms

 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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- A -

adaptive niches   click this icon to hear the preceding term pronounced
see ecological niches.
allogrooming   click this icon to hear the preceding term pronounced
see grooming.
anthropoid   click this icon to hear the preceding term pronounced
an animal within the primate suborder Anthropoidea.  Monkeys, apes, and humans are anthropoids.
arboreal   click this icon to hear the preceding term pronounced
tree-living; referring to animals that are adapted to life in the trees.  Arboreal animals spend most of their time scampering around in trees rather than on the ground, in the air, or water.  See semi-terrestrial and terrestrial.

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- B -

binocular vision   click this icon to hear the preceding term pronounced
seeing with two eyes that have an overlapping field of view.  This is essential to stereoscopic vision.
bipedalism   click this icon to hear the preceding term pronounced
referring to walking and running on two feet.  Humans are the only fully bipedal primates today.
brachiators    click this icon to hear the preceding term pronounced
animals that travel through the trees by swinging under branches with a hand over hand motion.  The smaller apes and some New World monkeys brachiate.  Brachiation is also referred to as suspensory climbing.

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- C -

carnivorous   click this icon to hear the preceding term pronounced
eating only meat.  Animals that have this sort of diet are carnivores.  See herbivorous and omnivorous.
cerebral cortex   click this icon to hear the preceding term pronounced
the outer portion of a brain's cerebrum (two upper frontal lobes of the brain).  This is the area associated with coordination of sensory and motor information as well as higher thought processes.
cheek pouches
cheeks that are so elastic that they can expand to allow temporary storage of food.  This is useful when there is competition.  Old World monkey in the subfamily Cercopithecinae (macaques, baboons, etc.) have cheek pouches of this sort.
Chordata   click this icon to hear the preceding term pronounced
the phylum of animals that is characterized by elongated bilaterally symmetrical bodies.  In some phase of their life cycle, they have a notochord and gill slits or pouches. Chordates also often have a head, a tail, and a digestive system with an opening at both ends of the body. The Chordata include fish, amphibians, reptiles, birds, mammals, and 2 invertebrate subphyla (tunicates and lancelets).
chordate   click this icon to hear the preceding term pronounced
a member of the phylum Chordata.
clavicles    click this icon to hear the preceding term pronounced
collarbones; the bones that connect the sternum with the scapula.  A single clavicle on each side of the body goes from the center of the upper chest to the shoulders.
collarbones
see clavicles.
core body temperature
the temperature of the internal organs in the chest cavity, abdominal region, and head in animals.
cusps   click this icon to hear the preceding term pronounced
the elevated, somewhat pointed portions of the chewing surfaces on premolar and molar teeth.

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- D -

dental formula
the quantity of each type of tooth (e.g., incisor, canine, premolar, and molar) in each quadrant of the mouth, counting from the front.  The human dental formula is 2.1.2.3.  The Old World monkeys and apes also share this dental formula.
digits  click this icon to hear the preceding term pronounced
fingers and toes.  See pentadactylism.
displays
visual messages, or body language, used by primates and other animals primarily to communicate anger, fear, and other basic emotions.  Displays are a strong indication of an animal's emotional state.
diurnal   click this icon to hear the preceding term pronounced
being awake and active during the daylight hours but sleeping during the nighttime.  See nocturnal.
DNA   click this icon to hear the preceding term pronounced    (deoxyribonucleic acid click this icon to hear the preceding term pronounced)
a large organic molecule that stores the genetic code for the synthesis of proteins.  Each chromosome consists mostly of a DNA molecule.  DNA is composed of sugars, phosphates and bases arranged in a double helix shaped molecular structure.  Segments of DNA correspond to specific genes.

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- E -

ecological niches   click this icon to hear the preceding term pronounced
specific micro-habitats in nature to which populations or organisms adapt.   They are usually seen in terms of being food getting opportunities in the environment.
estrus   click this icon to hear the preceding term pronounced
the period of time when female animals are sexually excited and receptive to mating.  Estrus occurs around the time of ovulation in many species.

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- G -

genome   click this icon to hear the preceding term pronounced
the full genetic complement of an individual (or a species).  In humans, it is estimated that each individual possesses approximately 2.9 billion nucleotides in all of the DNA that makes up his or her genome.
gestation   click this icon to hear the preceding term pronounced
the period between conception and birth during which an unborn young is within its mother's uterus.  Pregnancy is another word for gestation.  
great apes
the gorillas, common chimpanzees, and bonobos of Africa and the orangutans of Southeast Asia.  These species are referred to as great apes because they are the largest apes.  See lesser apes.
grooming
carefully picking through hair looking for insects, twigs, and other debris.  Primates frequently allogroom, which is to say they groom each other to reinforce social relationships and reduce psychological tension.

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- H -

herbivorous   click this icon to hear the preceding term pronounced
eating only vegetable foods.  Animals that have this sort of diet are herbivores or vegetarians. See carnivorous and omnivorous.
homologies   click this icon to hear the preceding term pronounced
anatomical structures in different species that are similar due to descent from a common ancestor that had them.  Homologies are also referred to as homologous structures or features

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- I -

incisors   click this icon to hear the preceding term pronounced
chisel shaped teeth at the front of the mouth in mammals.  All primates normally have 8 incisors (2 in each quadrant of the mouth).  The common mammal pattern is 12 incisors (3 in each quadrant).  See dental formula.
invertebrate   click this icon to hear the preceding term pronounced
an animal that lacks an internal skeleton.  All animals other than fish, amphibians, reptiles, birds, and mammals are invertebrates.  Approximately 95% of all animals are invertebrates.
ischial callosities   click this icon to hear the preceding term pronounced
hairless, callused areas on either side of the rump of monkeys in the Old World monkey subfamily Cercopithecinae (macaques, baboons, etc.) and the small apes of Asia. 

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- J -

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- K -

knuckle walking
the form of four legged locomotion used by gorillas and chimps.  They walk on the soles of their feet but not on the palms of their hands.  They bend their fingers and support the head end of their bodies with their knuckles instead of their open palms.

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- L -

lesser apes
the gibbons and siamangs of Southeast Asia.   These species are referred to as lesser apes because they are the smallest apes. See great apes.
locomotor patterns   click this icon to hear the preceding term pronounced
the methods an animal uses to move.  These may include such things as swimming, jumping, walking, brachiating, etc.

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- M -

mammal   click this icon to hear the preceding term pronounced
a class of warm blooded, usually hairy animals, that feed their young with milk secreted by the mammary glands of females.  All primates are mammals.
 
manual dexterity   click this icon to hear the preceding term pronounced
referring to the ability to manipulate objects with the hands.
monogamous   click this icon to hear the preceding term pronounced
having only one mate at a time.  Monogamy is rare among nonhuman primates but common among humans.

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- N -

New World
The New World is the Americas.  The Old World is Europe, Asia, and Africa.  This distinction is an ethnocentric reflection of the European origin of our modern sciences.
niche
see ecological niches.
nocturnal   click this icon to hear the preceding term pronounced
being awake and active when it is dark but sleeping during the day.  See diurnal.
nuclear family
an adult male and female mating pair along with their children.

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- O -

Old World
The Old World is Europe, Asia, and Africa.  The New World is the Americas.  This distinction is an ethnocentric reflection of the European origin of our modern sciences.
olfactory   click this icon to hear the preceding term pronounced
the sense of smell.  With the exception of prosimians, primates are relatively poor at olfactory sensing.
omnivorous   click this icon to hear the preceding term pronounced
the ability to live by eating both meat and vegetable foods.   See carnivorous and herbivorous.
order
a Linnaean classification category above the level of species and genus and below class.  Each order can consist of many species and genera.

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- P -

pelvis   click this icon to hear the preceding term pronounced
the bowl-shaped ring of bones in the hip region at the base of the torso, supporting the spinal column and resting on the legs.  It is also referred to as the pelvic girdle.
pentadactylism    click this icon to hear the preceding term pronounced
having five digits on the end of feet and hands.  This trait is characteristic of all primates except for the spider monkey which has five toes on each foot but only four fingers on each hand.  Pentadactylism is an ancient mammalian trait that was inherited from their reptile ancestors.
peripheral vision   click this icon to hear the preceding term pronounced
the field of view outside of the line of direct site.   Primates and most other binocular animals only see two dimensions (2-D) peripherally since these are areas beyond their overlapping field of view.  See stereoscopic vision.
pheromones   click this icon to hear the preceding term pronounced
chemicals produced and secreted by an animal that can have a powerful affect on the behavior and development of other animals (usually in the same species).  Pheromones are common throughout the animal world, including humans.  
placental mammal   click this icon to hear the preceding term pronounced
the infraclass of mammal species in which females produce a placenta to connect the fetus to the uterus.   This enables nutrients and oxygen to get to the fetus and provides a means of eliminating waste products.  As a result, placental mammals can carry their young within the uterus until late in fetal development.  This has a selective advantage because it results in decreased infant mortality.  Placental mammals are also called Eutherian click this icon to hear the preceding term pronounced mammals.  Included in this infraclass are dogs, cats, bears, whales, monkeys, humans, etc. 
prehensile   click this icon to hear the preceding term pronounced
the ability to physically grasp something.  All primates have prehensile hands.  With the exception of humans, they all also have effective prehensile feet.  The larger New World monkeys (Cebidae) have prehensile tails as well.  Some marsupials living in the eastern islands of Indonesia and New Guinea also have this characteristic.

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- Q -

quadrupedal   click this icon to hear the preceding term pronounced
having a four footed means of locomotion.  Humans are bipedal all other primates are primarily quadrupedal.

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- R -

rhinarium    click this icon to hear the preceding term pronounced
a moist, hairless pad of skin at the end of a nose.  This is a characteristic of prosimians (except for tarsiers), dogs, and some other animals.

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- S -

sacculated   click this icon to hear the preceding term pronounced
referring to a stomach with "saccules," or sack-like compartments, in which bacteria slowly break down cellulose, thereby providing more useable calories.  Among the primates, only the Colobinae (colobus, langurs, and proboscis monkeys) have this characteristic.  Cows and some related animals also have sacculated stomachs.
savannas   click this icon to hear the preceding term pronounced
usually semi-arid plains regions covered with grasses and occasional scattered trees.
semi-terrestrial    click this icon to hear the preceding term pronounced
referring to animals that spend much of their day on the ground but usually return to the trees to sleep.  See arboreal and terrestrial.
septum   click this icon to hear the preceding term pronounced
the soft tissue separating the two nostrils of a mammal's nose.
sexual dimorphism   click this icon to hear the preceding term pronounced
referring to anatomical differences between males and females of the same species.  Primate males are usually significantly larger and more muscular than females.  This is especially true of semi-terrestrial monkeys and the great apes.  Humans are also sexually dimorphic.
sexual skin or swelling
a nearly hairless large swollen patch of skin around the genital area of females that becomes very prominent when they are in estrus click this icon to hear the preceding term pronounced.  These areas swell with fluids and turn bright pink or red due to hormonal changes that occur in preparation for ovulation.  The sexual skin also produces odors that excite males of the species. They become highly attentive to the females at this time.  Sexual skins are found among many of the Old World monkey species in the subfamily Cercopithecinae (e.g., baboons) as well as the chimpanzees and bonobos.
species
the largest natural population of organisms that can potentially interbreed to produce fertile offspring.  It is commonly assumed that members of one species are reproductively isolated from members of all other species (i.e., they cannot mate with them to produce fertile offspring.  However, we must be cautious in defining species with this criterion because members of very closely related species can sometimes produce offspring together, and a small fraction of those may be fertile to some degree.  This is the case with mules, which are the product of mating between horses and donkeys.  About one out of 10,000 mules is fertile.  This suggests that some species differences are a matter of degree.
  drawing of a human head shown from above with the field of view of each eye superimposed to show the overlapping vision range
stereoscopic vision    click this icon to hear the preceding term pronounced
the ability to see things in three dimensions (3-D).   Stereoscopic vision is what allows for true depth perception.  See peripheral vision and binocular vision.
subadult
the stage of maturation in which animals are beyond infancy and early childhood but are not yet fully grown.
suspensory climbing
see brachiators.
symbol   click this icon to hear the preceding term pronounced
a thing, such as a word, that can represent something else that is not here and now.  The meaning of a symbol is arbitrary and is given by those who use it.  Human languages are systems of symbols.

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- T -

tactile pad   click this icon to hear the preceding term pronounced
a skin surface that is unusually sensitive to pressure, temperature, and pain because there are high concentrations of nerve endings immediately below these areas.
taxonomy   click this icon to hear the preceding term pronounced
naming, describing, and classifying organisms into different categories on the basis of their appearance and other diagnostic characteristics as well as their evolutionary relationships.  The biological sciences primarily use the Linnaean classification system for this purpose.
terrestrial   click this icon to hear the preceding term pronounced
referring to animals that spend most of their time on the ground rather than in the air, water, or trees.  See arboreal and semi-terrestrial.

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- V -

Vertebrata    click this icon to hear the preceding term pronounced
the subphylum of chordates that includes the animals that possess a spinal chord protected by a segmented vertebral column of cartilage and/or bone.
vertebrates   click this icon to hear the preceding term pronounced
members of the animal subphylum Vertebrata.
vestigial   click this icon to hear the preceding term pronounced
referring to body parts that are remnants of parts that were more fully developed and functional in an earlier stage of evolution in the species.
vocalizations
sounds produced primarily by the throat and mouth.  Primate vocalizations include a wide variety of hoots, whistles, grunts, etc.

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- W -

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- X -

X-linked   click this icon to hear the preceding term pronounced
referring to a gene that is carried by a X sex chromosome.

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- Y -

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- Z -

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Copyright 1998-2012 by Dennis O'Neil. All rights reserved.
illustration credits