Bio. Anthro Exam 2 Terms

Linnaean Classification

Kingdom, Phylum, Class, Order, Family, Genus, Species

Homology

When two or more taxa share characteristics because they inherited them from a common ancestor.

Analogy

When two or more taxa exhibit similar traits that have evolved independently, the similar traits evolve due to similar selective pressures. (Also sometimes called convergent evolution, parallel evolution, or homoplasy)

Primitive trait

A trait that has been inherited from a distant ancestor.

Derived trait

A trait that has been recently modified, most helpful when assigning taxonomic classification.

generalized traits

A trait that is useful for a wide range of tasks. EX: Opposable thumbs

Specialized traits

A trait that has been modified for a specific purpose.

Opposable thumbs

thumb that enables grasping objects and using tools

Postorbital bar

A bony ring that surrounds the eye socket, open at the back, all primates have it

Postorbital Plate

A bony plate that provides protection to the side and back of the eye.

Postorbital Closure

when the orbits are posteriorly encased in bone; closure is found in all anthropoids

Tradeoff

When an organism, which is limited in the time and energy it can put into aspects of its biology and behavior, is shaped by natural selection to invest in one adaptation at the expense of another.

life history

Refers to an organism's pace of growth, reproduction, life span, etc.

Incisors

The spatula-shaped teeth at the front of the mouth

Premolars

Smaller than the molars, used for chewing. In primates, these teeth usually have one or two cusps.

Molars

The largest teeth at the back of the mouth; used for chewing; in primates, these teeth usually have between three and five cusps.

Canines

In most primates, these are the longest of the teeth, often conical in shape and used as a weapon against predators or others of their species.

Sexually dimorphic

When a species exhibits sex differences in morphology, behavior, hormones, and/or coloration.

dental formula

The number of each type of tooth in one quadrant of the mouth, written as number of incisors: canines: premolars: molars.

Cusps

The bumps on the chewing surface of the premolars and molars, which can be quite sharp in some species. Some species have 3 and 5 cusps and one primate had 6 cusps.

Frugivores

Having a diet consisting primarily of fruit, has a intermediately complex digestive tract and large incisors.

insectivores

Eats insects, has sharp pointed molars

Folivores

animals that eat a diet composed mainly of leaves, or foliage, Have shearing crests and a complex digestive tract

Gummivores

Having a diet consisting primarily of gums and saps, not discussed in great detail

Bunodont Molars

Low, rounded cusps on the cheek teeth.

Diurnal

Active during the day.

Nocturnal

active at night

cathemeral

Active throughout the 24-hour period.

Locomotion

How an organism moves around

Vertical clinging and leaping

A locomotor pattern in which animals are oriented upright while clinging to vertical branches, push off with hind legs, and land oriented upright on another vertical branch.

Quadrupedalism

Moving around on all fours, most common form of locomotion for primates

Brachiation

A form of locomotion in which the organism swings below branches using the forelimbs. The primate needs longer arms and legs, flexible shoulders and wrists and a short lower back, and no tail.

Prehensile tails

A tail that is able to hold the full body weight of an organism, which often has a tactile pad on the underside of the tip for improved grip, used by semi brachiators

Semi-brachiation

A form of locomotion in which an organism swings below branches using a combination of forelimbs and prehensile tail.

Bipedalism

Habitually using only two legs to walk. Most mammals do not do it for long distances except for humans.

Grooming claw

A claw present on the second pedal digit in strepsirrhines.

Tooth (dental) Comb

A trait of the front, lower teeth of strepsirrhines in which, typically, the four incisors and canines are long and thin and protrude outward.

Rhinariums

Wet noses, produced when the nose is connected to the upper lip.

Bilophodont

Molar pattern of cercopithecoid monkeys in which there are usually four cusps that are arranged in a square pattern and connected by two ridges.

Ischial callosities

A flattened area of the ischium on the pelvis over which calluses form; functioning as seat pads for sitting and resting atop branches.

Y-5 molars

molar that has five cusps with grooves running between them, forming a Y shape. This is characteristic of hominoids

Sagittal Crests

A bony ridge along the top/middle of the skull, used for attachment of chewing muscles.

Male bimaturism

Refers to the alternative reproductive strategies in orangutans in which males can delay maturation, sometimes indefinitely, until a fully mature, "flanged" male disappears; allows male Orangutans to breed with females without more dominant Orangutans knowing

abundance

How much food is available in a given area.

Distribution

How food is spread out

basal metabolic rate (BMR)

he rate at which an individual uses energy when at rest, increases depending on the size of the animal

Direct Competition

The rivalry between two animals that eat similar food recourses and directly fight each other for it

Indirect competition

Primates engage in indirect competition, which is eating food before another animal finds it

Sympatric

Two or more species that overlap in geographic distribution.

Allopatric

Two or more species that do not overlap in geographic distribution.

Competitive exclusion principle

The idea that two species that compete for the exact same resources cannot coexist.

Niche

The role of a species in its environment; how it meets its needs for food, shelter, etc

Niche partitioning

The process by which potentially competing species reduce competition by using the environment differently.

Fission-fusion

Societies in which group composition is flexible, such as chimpanzee and spider monkey societies. Individuals may break up into smaller feeding groups (fission) and combine into larger groups (fusion).

Interbirth intervals

The length of time between successive births

parental investment

Any time or energy a parent devotes to the current offspring that enhances its survival (and eventual reproductive success) at the expense of the parent's ability to invest in the next offspring.

Social learning

The idea that new behaviors can be acquired by observing and imitating others.

Infanticide

The killing of infants of one's own species, male investment

paternity certainty

Confidence in which male fathered an offspring.

Sexual selection

An aspect of natural selection in which the selective pressure specifically affects reproductive success (the ability to successfully breed and raise offspring).

Intrasexual selection

Selection for traits that enhance the ability of members of one sex to compete amongst themselves.

Intersexual selection

The selection for traits that enhance the ability of the members of one sex to attract the attention of the other.

Sperm competition

Competition between sperm of two or more different males to fertilize the same egg.

paternity confusion

When males are uncertain if they fathered an offspring. This is often a female strategy to reduce the chance of infanticide.

Polygyny

A mating system in which one male mates with multiple females, Orangutans and Mountain Gorillas

Polygamy

A mating system in which multiple males mate with multiple females, Chimpanzees

Polyandry

A mating system in which multiple males mate with a single breeding female.

Piloerection

Raising one's hair or fur in an effort to look bigger.

Sexual swelling

Area of the hindquarters that change in size, shape and often color over the course of a female's reproductive cycle, reaching maximum size at ovulation. Occurs in many Old World primate species.

Extinct

A word used to describe species that are no longer represented by living organisms

Extant

still existing; not exterminated, destroyed, or lost

Deep time

James Hutton's theory that the world was much older than biblical explanations allowed. This age could be determined by gradual natural processes like soil erosion.

Uniformitarianism

The theoretical perspective that the geologic processes observed today are the same as the processes operating in the past.

Catastophism

The theoretical perspective that Earth is young and that any changes in the landscape resulted from sudden catastrophic events like volcano eruptions and floods.

Fossils

Mineralized copies of organisms or activity imprints.

Pangaea

A supercontinent that existed during the Paleozoic era, started splitting 200 million years ago

Continental drift

The slow movement of continents over time.

Taphonomy

The study of what happens to an organism after death. Important to biological anthropology

Fossilization

when living material is replaced with mineral substances in the remains of an organism

Lithification

The process by which the pressure of sediments squeeze extra water out of decaying remains and replace the voids that appear with minerals from the surrounding soil and groundwater.

Relative dating

Dating methods that do not result in numbers of years but, rather, in relative timelines wherein some organisms or artifacts are older or younger than others, remember the lab; based on observation

Stratigraphy

A relative dating method that is based on ordered layers or (strata) that build up over time

James Hutton

Father of deep time, who developed stratigraphy

Law of superposition

The scientific law that states that rock and soil are deposited in layers, with the youngest layers on top and the oldest layers on the bottom.

Biostratigraphy

A relative dating method that uses other plant and animal remains occurring in the stratigraphic context to establish time depth.

Cultural Dating

The relative dating method that arranges human-made artifacts in a time frame from oldest to youngest based on material, production technique, style, and other features.

Fluorine dating

A relative dating method that analyzes the absorption of fluorine in bones from the surrounding soils.

Chronometric dating

Provides specific dates and time ranges; based on the measurement of radioactive decay of particular elements

Isotopes

Atoms of a given element that have different numbers of neutrons

Stable Isotopes

Variants of elements that do not change over time without outside interference.

Unstable Isotopes

Variants of elements that spontaneously change into stable isotopes over time

Radiocarbon Dating

The chronometric dating method based on the radioactive decay of C-14 in organic remains.

Potassium-argon (K-Ar) dating

A chronometric dating method that measures the ratio of argon gas in volcanic rock to estimate time elapsed since the volcanic rock cooled and solidified. See also argon-argon dating.

argon-argon dating

A chronometric dating method that measures the ratio of argon gas in volcanic rock to estimate time elapsed since the volcanic rock cooled and solidified. See also potassium-argon dating.

Sediment cores

Core samples taken from lake beds or other water sources for analysis of their pollen.

Diastema

A space between the teeth, usually for large canines to fit when the mouth is closed

convergent evolution

The independent evolution of a morphological feature in animals not closely related (e.g., wings in birds and bats).

Arboreal Hypothesis

the proposition that primates' unique suite of traits is an adaptation to living in trees, created by Fredrick Wood Jones

Visual Predation Hypothesis

the proposition that unique primate traits arose as adaptations to preying on insects and on small animals, created by Matt Cartmill

Angiosperm-Primate Coevolution Hypothesis

primates and angiosperm (flowers) co-evolved to be better suited for fruit eating, created by Robert Sussman ඞ