Download Evolution- over time new types of organisms are developed from

Evolution- over time new types of organisms are developed from preexisting organisms
Strata- rock layers that are formed when new rock layers are deposited
Natural Selection- a process in which organisms that adapt well to a different environment will survive
and grow in population more easily than those that don’t
Adaptation- a trait that makes helps individuals live in their environment
Fitness- a measure of an individual’s genes carried on to the next generation
Fossil- the evidence of an organism that died a long time ago
Superposition- a principle that states if the location of rock strata has yet to be disturbed then the
lowest stratum was formed before the strata above it
Relative Age- a fossil’s age compared to other fossils’ ages
Absolute Age- the time since the formation of the object
Biogeography- the study of locations of organisms around the world
Homologous Structures- anatomical structures that happen in different species that originated by
heredity from a structure in the most recent common ancestor of the species
Analogous Structures- closely related functions but don’t derive from the same ancestral structures
Vestigial Structures- structures where evidence of evolution is found that serve no function but that
resembles structures with functional roles in related organisms
Phylogeny- the connections by ancestry among groups of organisms
Convergent Evolution- a process in which different species evolve similar traits
Divergent Evolution- a process in which the descendants of a single ancestor become more varied in
species that each fit different parts of the environment
Adaptive Radiation- a new species in a new place will undergo divergent evolution until the population
fills many parts of the environment
Artificial Selection- a process tat happens when a human breeder chooses individuals that will parent
the next generation
Coevolution- a situation when two or more species have evolved adaptations to each other’s influence
Population Genetics- the study of evolution from a genetic point of view
Microevolution- a change in the collective genetic material of a population
Bell Curve- the shape of a curve looks like a bell
Gene Pool- the total genetic information available in a population
Allele Frequency- determined by dividing the number of a certain allele by the total number of alleles of
all types in the population
Phenotype Frequency- equal to the number of individuals with a particular phenotype divided by the
total number of individuals in the population
Hardy-Weinberg Genetic Equilibrium- a principle that states that the frequency of alleles in a population
does not change over generations unless outside forces act on the population
Immigration- the movement of individuals into a population
Emigration- the movement of individuals out of a population
Gene Flow- the process of genes moving from one population to another
Genetic Drift- the phenomenon by which allele frequencies in a population change as a result of chance
Sexual Selection- when females tend to choose the males they mate with based on certain traits
Stabilizing Selection- individuals with the average form of a trait have the highest fitness
Disruptive Selection- individuals with either extreme variation of a trait have greater fitness than
individuals with the average form of the trait
Directional Selection- individuals that show a more extreme form of a trait have greater fitness than
individuals with an average form of the trait
Speciation- the process of species formation
Morphology- the study of the form and structure of an organism
Biology Species Concept-a population of organisms (species) that can interbreed successfully but can’t
breed with other species
Geographic Isolation- the physical departure of members of a population
Allopatric Speciation- a result when species arise as a result of geographic isolation
Reproductive Isolation- results from barriers to successful breeding between population groups in the
same area
Prezygotic Isolation- or premating isolation happens before fertilization
Postzygotic Isolation- or postmating isolation happens after fertilization
Sympatric Speciation- happens when two subpopulations become reproductively isolated within the
same geographic area
Gradualism- the idea that speciation happens at a regular or gradual rate
Punctuated Equilibrium- a model of evolution in which short periods of dramatic change in species
along with mass extinctions and fast speciation are separated by long periods of little or no
change