Absolute Brain Size
The actual size of a brain, usually expressed by a measure of weight or volume. Compare relative brain size.
The scientific study of the origin, the behavior, and the physical, social, and cultural development of humans.
Species that are members of the Families Hylobatidae (gibbons or “lesser apes”) and Hominidae (great apes: chimpanzee, gorilla, gibbon, orangutan and human).
Of, living in, or connected with trees.
An upright posture or form of locomotion that relies on the use of the legs without any assistance from the arms. Humans are the only species of primate that habitually use a bipedal form of locomotion.
Brachiation (pronounced bray kee ay’ shun)
A form of locomotion that relies on the arms without any assistance from the legs. The gibbons are the only true brachiators, although some other aboreal primates are considered semi- or modified brachiators.
Elastic cheeks that allow relatively large amounts of food to be held in the mouth temporarily, usually during foraging; found only in Old World primates.
A construct that references higher-order and complex operations of the brain. Cognition generally is held to be based on mental operations well beyond the bounds of simple associative learning. Its operations are posited whenver we obtain evidence of an organism achieving an understanding of a problem in which behavior reflects comprehension of over-arching principles rather than simple associations, especially in first-time efforts to meet a new challenge. The mastery of symbols and their representations for use in language and mathematics is generally held to be enabled by the operations of cognition.
The transmission of acquired patterns of behavior and problem solving across generations via social learning and rearing. At the human level, culture is reflected in art, discovery, educational institutions, family and community life. At the nonhuman levels, the transmission of learned signals, methods of hunting and foraging, tool fabrication and use, are generally accepted as products of enculturation.
DNA (deoxyribonucleic acid)
The sequence of nucleic acids that is commonly referred to as the genetic “blueprint” for each individual organism. DNA is one of the means of assessing the relative similarities that exist among species.
The process by which the characteristics of a population change over time in relation to the demands of the environment. Evolution is the foundation upon which all of biology rests and is the scientific explanation for the diversity of life on Earth.
Referring to organisms that have a diet composed primarily of leaves or other forms of vegetation; frequently used interchangeably with “leaf-eating.”
Referring to organisms that have a diet composed primarily of fruits.
Hard, thickened areas of hairless skin that are prominent on the rear ends of may species of Old World primates. These structures function primarily as sitting pads.
An acronym for the Lana Language project with the chimpanzee, Lana. Although Lana’s achievements were initially thought to be limited to analogs of language, across time it was clear that she had mastered several significant language skills.
Distinctive geometric symbols embossed on keys of a keyboard where each symbol was intended to function as a word. For a symbol to become a word it must acquire both a functional and symbolic equivalence with a specific referent. a referent might be a food, drink, a person, a place, a color, or the state of something (e.g., a window being open). the term was coined for the LANA Language Project of 1971 in which a chimpanzee was first introduced to language learning through use of a computer-monitored keyboard.
The study of the nature, structure, and variation of language, including phonetics, phonology, morphology, syntax, semantics, sociolinguistics, and pragmatics.
A female who rules a family, clan, or tribe.
New World Monkeys
All species of nonhuman primates that are native to the southernmost portion of North America (Mexico) and Central and South America.
Old World Monkeys
All species of monkey that are native to areas outside the Americas, chiefly Asia and Africa. Prosimians and apes may be correctly labeled Old World primates, but they are not monkeys.
For primates, referring to tails that can function as a third hand or foot by grasping, reaching, or holding. Prehensile tails are only found in the New World monkeys.
Any member of the order Primate. All primates have a shared set of physical features, such as forward-facing eyes, opposable digits, and relatively large brains for mammals of their size.
The study of any member of the order Primate.
Literally, “pre-monkey.” The more primitive species of primate, including the lemurs, lorisies, pottos, and galagos. Some sources include tarsiers as well, although this is debated among taxonomists. Monkeys and apes are not members of the prosimian group.
Relative Brain Size
The proportion of the body made up by the brain. Compare absolute brain size.
A flat, bony protrusion rising from the top of the skull. This structure is most exaggerated in male gorillas and serves as an attachment point for the muscles associated with chewing.
The difference in body size or structure that is correlated with the two sexes within a given species. For example, adult male orangutans may be twice the size of adult female orangutans.
Of two or more populations inhabiting the same geographic area.
The study of the rules whereby words or other elements of sentence structure are combined to form grammatical sentences.
The classification system introduced by Carolus Linnaeus that is based on how closely or distantly species are related to each other.
A comparative-psychological measurement of intelligence defined by Duane M. Rumbaugh in 1969. The measure is based on Harlow’s learning set training methods. The TI serves as a defensible measure of complex-learning skills and the abilities for transferring operationally defined amounts of learning to modified test conditions. This method defined a very high correlation between brain size and intelligence form prosimian to the great apes.