Download Biology First Six Weeks Vocabulary

Unit 6 Vocabulary – Evolution
TERM
DEFINITION
Adaptation
An alteration in an organism’s characteristics that better enables it to survive in its
environment
Anatomical Homologies
Similar anatomical structures that exist between species and can be identified as a
link to a common ancestor
Ancestry
An organism’s lineage of descendants
Biodiversity
The total variation of species within a given ecosystem
Biogeography
Study of past and present geographical distribution of species
Charles Darwin
Scientist who identified the process of natural selection; Darwin studied finches on
the Galapagos Islands
Developmental Homologies
Embryonic similarities between organisms of different species
Evolution
A change in the gene pool of a population that results in a successive change over
time
Fitness
The ability of an organism to survive and reproduce
Fossil Record
The total number of fossils, and their locations in rock formations and sedimentary
layers which provides information about those organisms
Gene Flow
The movement of genes into and out of a population due to interbreeding between
different populations
Gene Pool
The total number of alleles for each gene that is available within a population
Genetic Drift
Random changes in the frequency of alleles within a gene pool; greater effect on
small populations
Genetic Variation
The variety of gene combinations that exist within a population
Gradualism
The theory that species evolve slowly and gradually over extended periods of time
Homology
Two characteristics that are similar because they originated from a common ancestor
Limiting Factor
A biotic or abiotic environmental factor that restricts the growth of a population
Migration
A response to changes in an ecosystem that results in entire populations moving from
one ecosystem to another
Molecular Homologies
DNA and RNA similarities between organisms
Natural Selection
A mechanism of evolution. The process that results in the survival or reproductive
fitness of an individual or group that is best adapted to their environment (survival of
the fittest).
Overpopulation
More organisms in an area than an ecosystem can support
Population
All of the organisms of one species within a particular ecosystem
Recombination
The process by which genetic material from different individuals becomes combined
Reproductive Success
An organism’s ability to pass on its genes
Speciation
An evolutionary event that results in the formation of a new species
Stasis
Describes a long period of time in which little or no change occurs within a species
Vestigial Structure
The remnants of a structure that is no longer needed