Eolution Unit Vocabulary List
Adaptation – An inherited characteristic that
increases and organism’s chance of survival.
Adaptive Value – Having traits that enable an
organism to survive in a changing environment.
Artificial Selection – selection by humans for breeding of useful traits from
the natural variation among different organisms.
Biodiversity – Biological diversity; the number of different organisms in the
biosphere. (Remember high levels of biodiversity is a good thing.)
Competition - The struggle among organisms, both of the same and of
different species, for food, space, and other things they need to stay alive.
Species that occupy the same niche compete most.
Diversity – differences between organisms; variation. (Remember genetic
diversity is a good thing.)
Evolution – Change in a kind of organism over time; process by which
modern organisms have descended from ancient organisms.
Extinction – Disappearance of a species from the Earth.
Fitness (Fittest) – The individuals that have the best adaptations to survive
in their environment.
Fossil Record – The information about past life, including the structure of
organisms, what they ate, in what environment they lived and the order in
which they lived.
Geological Time Scale – Scale used by paleontologists to represent
evolutionary time.
Genetic Variation – Differences in the genetic makeup of individuals of the
same species. Clones have no genetic variation. Genetic variation drives
evolution.
Homologous Structures – structures that have different mature forms in
different organisms but develop from the same embryonic tissue. Examples:
a whale’s fin, a bird’s wing and a mammal’s leg.
Natural selection – Process by which individuals that are better suited to
their environment survive and reproduce most successfully; also called
survival of the fittest.
Niche – The place a certain species occupies in its environment. Niche
includes the job it does, the food it eats, the place it lives, etc…
Speciation – Formation of a new species.
Species – A group of similar organisms that can breed and produce fertile
offspring.