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Evolution

Terms in this set (46)

microevolution
the changes in one gene pool of a population over generations
macroevolution
speciation
population
the members of one species in one place, smallest group that can evolve
evidence for evolution
fossil record, comparative anatomy, comparative biochemistry, comparative embryology, molecular biology, biogeography
prokaryotic cells
first organisms to develop on earth
homologous structures
same internal structure, different function
analogous structure
same function, different internal structure
vestigial structure
evidence that anatomy has evolved, useless structures to us now
comparative biochemistry
organisms that have a common ancestor will have common biochemical pathways
comparative embryology
closely related organisms go through similar stages in their embryonic development because of a common ancestor
molecular biology
comparison of cytochrome c in aerobic organisms can show the relationships between organisms
biogeography
continental drift and Pangaea changed the species and distribution
Lamarck's Theory of Evolution
individuals change in response to their environment
Darwin's Theory of Evolution
populations grow exponentially, overpopulate, and exceed their resources; overpopulation leads to competition; there is variation within a population; natural selection / survival of the fittest
types of natural selection
stabilizing, diversifying/disruptive, directional
stabilizing selection
eliminates the extremes and favors the more common intermediate forms
disruptive/diversifying selection
increases the extreme types in a population and decreases the intermediate forms, may result in speciation
directional selection
one phenotype replaces the other in the gene pool
sources of variation within a population
mutation, genetic drift, and gene flow
mutation
changes in genetic material, raw material for evolutionary change
genetic drift
change in the gene pool due to chance
bottleneck effect
natural disasters reduce the size of a population nonselectively, results in a loss of genetic variation
founder effect
small population breaks away from a larger one to colonize a new area, does not represent the gene pool of the original larger population
gene flow
movement of alleles into/out of a population
Hardy-Weinberg equilibrium
large population, isolated (no migration), no mutations, random mating, no natural selection
species
a population whose members have the potential to interbreed in nature and produce viable, fertile offspring
speciation by isolation
geographic isolation, polyploidy, habitat isolation, behavioral isolation, temporal isolation, reproductive isolation
geographic isolation
occurs when species are separated by geography, allopatric speciation
polyploidy
occurs in plants, mutation from nondisjunction in meiosis, these plants cannot reproduce with normal n plants
habitat isolation
2 organisms live in the same area but encounter each other rarely
behavioral isolation
2 animals become isolated from each other because of some change in behavior by 1 member or group
temporal isolation
isolation because of differences in mating time
reproductive isolation
closely related species may be unable to mate because of anatomical incompatibility
patterns of evolution
divergent, convergent, parallel, coevolution, adaptive radiation
divergent evolution
when a population becomes isolated from the rest of the species and becomes exposed to new selective pressures, results in homologous structurs
convergent evolution
when unrelated species occupy the same environment, are subjected to similar selective pressures and show similar adaptations, results in analogous structures
parallel evolution
2 related species have made similar evolutionary adaptations after their divergence from a common andestor
coevolution
mutual evolutionary set of adaptations of 2 interacting species
adaptive radiation
emergence of numerous species from a single common ancestor introduced into an environment
gradualism
theory that organisms descend from a common ancestor gradually, over a long period of time, in a linear or branching fashion
punctuated equilibrium
theory that new species appear suddenly after long periods of no change
spontaneous generation
theory that living things emerge from no living or inanimate objects
heterotroph hypothesis
the first cells on earth were anaerobic heterotrophic prokaryotes
characteristics that enabled animals to move to land
lungs, skin, limbs, mechanisms for internal fertilization, shell
characteristics that enabled plants to move to land
roots, supporting cells, vascular tissue, cutin on leaves, and seeds
major extinction events
Permian extinction, Cretaceous extinction
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