47 terms


inherited characteristic that increases an organism's chance of survival
adaptive radiation
the development of many different forms from an originally homogeneous group of organisms as they fill different ecological niches
one of two alternate forms of a gene that can have the same locus on homologous chromosomes and are responsible for alternative traits
allopatric separation
when a geographical barrier physically isolates populations and blockes gene flow
ex: antelope squirrel on south of grand canyon are different species as those on the north side
analogous structure
structures that are not the same in form but are used for the same purpose ex: bird wing and fly wing
artificial selection
The selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits.
behavioral isolation
form of reproductive isolation in which two populations have differences in courtship rituals or other types of behavior that prevent them from interbreeding
bottle neck effect
natural disaster eliminates most of the population- members left contribute the alleles for the new pop.
Part of Horiz. Spp Concept, plugs into population genetics framework. Species are groups of interbreeding natural populations that are reproductively isolated. If individuals interbreed, allele frequencies stay similar within population. If no interbreeding, alleles between populations vary. Can Explain similarities within species. Concerned with isolating mechanisms like Pre/Post-zygotic barriers. Probs with BSC is concerning asexual organisms like bacteria, fossils and poorly known species where interbreeding cannot be tested, also incomplete isolation in ring spp or hybrid zones.
a system of biological taxonomy based on the quantitative analysis of comparative data and used to reconstruct cladograms summarizing the (assumed) phylogenetic relations and evolutionary history of groups of organisms
diagram that shows the evolutionary relationships among a group of organisms
the occurrence of two or more things coming together
convergent evolution
process by which unrelated organisms independently evolve similarities when adapting to similar environments
derived character
Characteristic that appears in recent parts of a lineage, but not in its older members
the act of moving away in different direction from a common point
founder effect
when a few individuals become isolated from a larger population, this smaller group may establish a new population whose gene pool isn't reflective of the source population
sequence of DNA that codes for a protein and thus determines a trait
gene flow
exchange of genes between populations
gene pool
combined genetic information of all the members of a particular population
genetic drift
The gradual changes in gene frequencies in a population due to random events
genetic equilibrium
condition in which the frequency of alleles in a population remains the same over generations
genetic makeup of an organism
geographic isolation
Form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water
hardy weinberg equilibrium
condition that occurs when the frequency of alleles in a particular gene pool remain constant over time
having two different alleles for a trait
homologous structures
Structures in different species that are similar because of common ancestry.
homozygous dominant
Both alleles (factors) for a trait are the same and dominant (AA)
homozygous recessive
Both alleles (factors) for a trait are the same and recessive (aa)
lamark vs darwin
LaMarck (1809)
Tendency toward perfection
Use and Disuse
Inherit acquired traits

Darwin (1859)
Heritable traits
said human population cannot continue to increase exponentially; consequences will be war, famine & disease
natural selection
a natural process resulting in the evolution of organisms best adapted to the environment
null hypothesis
hypothesis that states there is no difference between two or more sets of data making it opposite of the research hypothesis
Physical characteristics of an organism, determined by genotype
phylogenic tree
a branching diagram that shows how organisms are related through evolution
a group of organisms of the same species populating a given area
punctuated equilibrium
pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change
radiometric dating
the process of measuring the absolute age of geologic material by measuring the concentrations of radioactive isotopes and their decay products
reproductive isolation
Separation of species or populations so that they cannot interbreed and produce fertile offspring
a change from one state to the opposite state
scientific name
the two-part, scientifically recognized name given to an organism, consisting of its genus and species. for some reason it is written in a dead language
a form of natural selection in which individuals with certain inherited characteristics are more likely to obtain mates
the formation of new species as a result of evolution
sympatric isolation
two subpopulations become reproductively isolated within the same geographic area
practice of classifying plants and animals according to their presumed natural relationships
timing isolation
a reproductive barrier; different animals go into heat at different times.
(biology) an organism that has characteristics resulting from chromosomal alteration
viable offspring
Offspring that can reproduce