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generation to generation change in the proportion of different inherited genes in a population that account for all of the changes that have transformed life over an immense time


inherited characteristic that improve an organism's ability to survive and reproduce in a particular environment

descent with modification

process by which descendants of ancestral organisms spread into various habitats and accumulate adaptations to diverse ways of life

natural selection

process by which individuals with inherited characteristics well-suited to the environment leave more offspring than do other individuals


preserved remains or marking left by an organism that lived in the past

fossil recordEartg

chronological collection of life's remains in sedimentary rock layers


no longer existing as a living species on Earth

homologous structure

similar structure found in more than one species that share a common ancestor

vestigial structure

remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species


group of individuals of the same species living in a particular area at the same time


difference among members of a species

artificial selection

selective breeding of domesticated plants and animals to produce offspring with desires genetic traits

gene pool

all of the alleles in all the individuals that make up a population

genetic drift

change in the gene pool of a population due to change


contributed that an individual makes to the gene pool of the next generation compared to the contributions of other individuals

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