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51 Cards in this Set

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  • Back
Alterations in the organisms genotype which result in slight changes in the organisms phenotype.
Scala Natura
“Ladder of Life”. First proposed by Aristotle, primitive organisms evolve upward in an attempt to achieve perfection.
Charles Darwin
Involved with “theory of evolution”.
Alfred Wallace
Naturalist/ collector. Living things were not “immutable”, but could change and even evolve into new species.
Jean Lamarck
French naturalist. First attempt to explain the diversity if life. Alternate theory of evolution proposed.
Acquired Characteristics
Environmental pressures and the internal needs could bring about changes in an animal or plant. Alternate theory of evolution proposed by Lamarck, stated that environmental pressure and internal needs could bring about characteristics.
Any change in allele frequency resulting from mutation, natural selection, gene flow, genetic drift or some combination of these.
Arise as completely new allele in a specific gene trait (phenotype) or entirely new gene (and resulting new trait/phenotype)
Caused by changes/alterations in DNA. Eg: deletions, inversions, transpositions/tandem repeats, etc.
2 Factors necessary for evolution
Environment which favors the mutation
Natural Selection
What determines which traits are more fit than others is the environment. Process in which Darwins theory of evolution states that features or traits which impart a survival advantage are selected by the environment.
Evolutionary modification in the structure or behavior in organisms over generations that makes them better suited to their enviroment.
Stabilizing Selection
Selection pressure which favors the intermediate for of gene trait and eliminates the extremes.
Disruptive Selection
Natural selection which favors the extremes and not the intermediate forms, as in the guppies in mountain streams of Venezuela.
Sexual Selection
One of the most important survival strategies. If organisms can not breed successfully, then it is doomed to extinction.
Adaptive radiation usually requires the presence of many vacant _______.
Gene Flow
Good gene flow tends to reduce or prevent evolution. Movement of individuals with their genetic makeup.
Genetic Drift
Random change in allele frequency or the loss of an allele over a series of generations.
Directional Selection
When one of the extreme/ homozygote forms are selected.
Founder Effect
If a small sub-population becomes isolated from the rest of the population, such as on an island, this population may begin to diverge into 2 or more species.
Bottleneck Effect
When a population is reduced by intense selection pressure or calamity, and is forced to re-build from a few individuals.
Allopatric Speciation
Type of speciation that occurs when a sub-population is physically separated from the parent population.
Sympatric Speciation
Speciation that occurs when there are on physical barriers.
Adaptive Radiation
Process whereby one species gives rise to not 2 but many species.
Darwin believed that evolution occurred at slow, steady rate referred today as _______ evolution.
Punctuated Equilibrium
Some evolutionists believe that evolution can occur in rapid busts.
Evolution that occurs within a branch (the evolution of variation of the same species)
Evolution of many species is sometime represented as a tree or bush. The evolution resulting from splits or divergences of branches.
Process of identifying and song out the many lines of descent that connect all species.
Evolution of the same or similar structure into organs of different functions.
Unrelated structures which evolve the same functions are referred to as ___________ structures.
Morphological Convergence
Process whereby different animals lineages evolve similar structural forms, for example the fish like appearance of a dolphin.
Molecular Clocks
Process whereby the rate at which mutations occur within DNA, are used to determine when certain evolutionary events occurred.
Hox Genes
Evolutionary “jump” from similar, related species to an entirely different class or organisms may have been made possibly by repetitive mutations in group of genes.
Competitive Advantage
Any trait which provides the animal a
competitive or survival advantage over others of its species.
Cambrian Explosion
The rapid appearance of complex life forms 540
Reproductive Isolation
anything which prevents individuals of a
population from interbreeding
Gene Pool
all the genetic variety (alleles) within a species
process of evolving new species; when no longer able to interbreed or produce fertile offspring.
the act or process of 2 sub populations begin to separate (diverge) genetically
branch of evolution dealing with lines of descent
relatedness or lines of descent
loss of species either by natural selection or man- induced act.
Extinction Event
point in the fossil record indicating the
disappearance of one or more species
K-T Extinction
65 million mya; loss of dinosaurs
“Big Dying”
end Permian extinction; 225 million years ago.
Fossil Record
the record of evolution as observed in the layers of rock
Morphological Divergence
when related organisms or structures
change in response to different environmental demands
DNA/ Protein Comparison
determining evolutionary relatedness by
comparing proteins or DNA
Mitochondrial Eve
mitochondrial DNA evidence indicating Homo sapiens evolved in East Africa 160,000 years ago.
First Life
3.5 billion years ago
Blue-green algae; represent earliest life forms; 3.50 billion years ago