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bio Unit 3a

The gradual change in a species over time Evolution
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits. natural selection
Any difference between individuals of the same species. Caused by mutations and sexual selection Variation
inherited characteristic that increases an organism's chance of survival Adaptation
the struggle between organisms to survive in a habitat with limited resources competition
scientist who formulated a theory of evolution by natural selection Charles Darwin
when the environment pushes an individual or population to adapt or evolve selective pressure
occurs when natural selection favors one of the extreme variations of a trait directional selection
occurs when natural selection favors the average forms of a trait stabilizing selection
natural selection in which most organisms are unlikely to survive, regardless of which adaptations they have. Often happens with natural disasters. disruptive selection
Organisms with certain traits must compete for the attention of a mate. sexual selection
Preserved remains of once-living organisms. These provide evidence of extinct species and common ancestors of currently living species. Fossils
A structure that is present in an organism but no longer serves its original purpose. Left over structures from an organism's ancestors. vestigial structures
Lamarck scientist who believed organisms evolved through acquired traits
Lyell He wrote Principles of Geology and said plants and animals had arisen, developed vairations and then became extinct
Malthus He wrote An essay on the principles of populations and said species outgrow the food supply, compete for resources, and struggle for survival
changes in a population that occur when organisms with favorable variations for that particular environment survive, reproduce, and pass these variations on to the next generation. natural selection
when species become separated and can no longer interbreed reproductive isolation
use of mathematical descriptions of genetic phenomena to help trace evolutionary trends within populations population genetics
adaptive radiation Darwin counted over a dozen different species of finches that he believed evolved from a single founding species. This is an example of ____________ ____________.
This is where unrelated species may independently evolve superficial similarities because of their adaptations to similar environments. convergent evolution
the variety of organisms, their genetic information, and the communities in which they live. biodiversity
the evolution of a new species speciation
when physical barriers cause populations to divide and prevent mating of individuals geographic isolation
evolution that occurs over a long period of time when adaptive changes accumulate slowly and steadily over time in a population gradualism
speciation that occurs quickly in rapid bursts, with long periods of stability punctuated equilibrium
structures in different species that are similar Example- seal's front flipper, horse's foreleg and human arm homologous structures
The percentage of an allele in a gene pool or in a population Gene Frequency
Mechanism of evolution that is random and can lead to decrease in genetic variation Genetic Drift
Mechanism of evolution that introduces alleles through migration Gene Flow
Variation Genetic differences in a population
Differential Reproductive Success Difference between individuals in a given generation and how many offspring they are able to leave
Created by: Jadis_08
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