Glossary

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
ice age
refers to a period of time when the climate of the earth was much cooler and drier, causing wide-spread glaciation; because the sea level tends to drop during period of high glaciation, Ice Ages are considered to be times of active animal migrations into otherwise isolated parts of the world.
iliac ala
[plural: iliac alea] the "wing" of the ilium; a large fan-shaped structure making up the lateral portion of the ilium.
ilium
[plural: ilia] the bone that fuses into the os coxa, forming the hip; the anterior component to the acetabulum.
industry
tools that have the same characteristics (such as material or design) and are limited to a geographic region.
inferior

a relative term used for bipedal hominins (those that travel on two legs) to describe features on the trunk that are closer to the feet; the opposite of superior. The term caudal is a synonym commonly used when referring to quadrupedal animals.

inherit
to acquire genetic material from a parent
innominate
[syn. os coxae or pelvis] the bone formed by the ilium, ischium, and pubis.
insectivore
a dietary category that describes animals that specialize in eating primarily insects.
insertion
[muscle insertion] a relative term describing the attachment of a muscle or ligament to a location on a bone that is farthest away from the center of the body, and the point on which the force of the muscle works.
instantaneous speciation
[syn. polyploidy] when the multiplication of chromosome (due to mistakes during meiosis or mitosis) produces instant reproductive isolation; only seen in plants.
interglacial
refers to an epoch or time frame between to ice ages, when glaciers have melted and the earth's temperature is relatively warmer.
intermembral index

a measure of the entire length of the arms in proportion to the entire length of the legs; calculated by diving the length of the humerus and radius, by the length of the femur and tibia, multiplied by 100.

interspecific
between different species.
interspecific allometry
looking at differences between size and shape of different species. For example, the size and shape difference between a human and a chimpanzee.
intraspecific
within the same species.
inversion

turning the sole of the foot towards the medial portion of the body; opposite of eversion.
invertebrate
an animal with no vertebral column (i.e., backbone or spine).
ischium
a bone that lies inferior to the ala and extends ventrally to join the pubis.
isotope
atoms of the same element that have the same number of protons, but differ in the amount of neutrons, therefore differing in atomic weight.
⇧ Return to Top