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43 Cards in this Set
- Front
- Back
Fossil
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The remains or traces of organisms from the past.
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Srata
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Compressed layers of sediment that have turned into superimposed layers of rock.
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Paleontology
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The study of fossils
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Catastrophism
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The principle that events in the past occurred suddenly and were caused by mechanisms different from those operating in the present.
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Uniformaitarianism
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A principle which states that mechanisms of change are constant over time.
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Adaptaions
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Characteristics of organisms that enhance their survival and reproduction in specific environments.
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Artificial Selection
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When humans modify a species over many generations by selecting and breeding individuals that possess desired traits.
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Natural Selection
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A process in which individuals that have certain heritable characteristics survive and reproduce at a higher rate than other individuals.
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Heritable Traits
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Traits that are passed from organisms to their offspring.
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Homology
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Similarity in characteristics resulting from a shared ancestry.
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Homologous Structures
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Structures that represent variations on a structural theme that was present in their common ancestor.
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Vestigial Structures
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Remnants of features that served important functions in the organism's ancestors.
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Evolutionary Tree
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A diagram that reflects evolutionary relationships among groups of organisms.
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Convergent Evolution
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The independent evolution of similar features in different lineages.
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Biogeography
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The geographic distribution of species.
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Continental Drift
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The slow movement of Earth's continents over time.
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Pangaea
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All of Earth's landmasses combined to for a landmass called Pangaea.
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Microevolution
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Change in allele frequencies in a population over generations.
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Average Heterozygosity
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The average percent of loci that are heterozygous.
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Geographic Variation
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Differences in the genetic composition of separate populations.
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Cline
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A graded change in a character along a geographic axis.
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Mutation
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A change in the nucleotide sequence of an organism's DNA.
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Point Mutation
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A change of one base in a gene.
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Population
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A group of individuals of the same species that live in the same area and interbreed, producing fertile offspring.
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Gene Pool
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Consists of all the alleles for all the loci in all individuals of the population.
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Hardy-Weinberg Equilibrium
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Principle that states that the frequencies of alleles and genotypes in a population will remain constant from generation to generation, provided that only Mendelian segregation and recombination of alleles are at work.
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Hardy-Weinberg Principle
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The gene pool of a population that is not evolving.
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Genetic Drift
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Cance events can also cause allele frequencies to fluctuate unpredictably from one generation to the next, especially in small populations.
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Founder Effect
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When a smaller group branches away and establishes a new population whose gene pool differs from the source population.
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Bottleneck Effect
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A severe drop in population size. Such as a fire or bomb lol
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Gene Flow
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The transfer of alleles into or out of a population due to the movement of fertile individuals or their gametes.
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Relative Fitness
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The contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals.
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Directional Selection
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Occurs when conditions favor individuals exhibiting one extreme of a phenotypic range, thereby shifting the frequency curve for the phenotypic character in one direction or the other.
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Disruptive Selection
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Occurs when conditions favor individuals at both extremes of a phenotypic range over individuals w intermediate phenotypes.
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Stabilizing Selection
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Selection that acts against both extreme phenotypes and favors intermediate variants.
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Sexual Selection
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A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.
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Sexual Dimorphism
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Marked differences between the two sexes in secondary sexual characteristics.
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Intrasexual Selection
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Selection within the same sex. Bucks fighting over a doe
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Intersexual selection
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When the a female choses her mate.
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Balancing Selection
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Occurs when natural selection maintains two or more form in a population.
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Heterozygote Advantage
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If individuals who are heterozypous at a particular locus have greater fitness than do both kinds of homozygotes.
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Frequency-Dependent Selection
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The fitness of a phenotype declines if it becomes too common in the population.
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Neutral Variation
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In humans, many of the nucleotide differences in non-coding sequences appear to confer no selective advantage or disadvantage.
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