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33 Cards in this Set

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What is biological evolution?

a change in the genetic composition of a population that occurs across generations

what evolves?

populations involve NOT individuals

what changes when something evolves?

the proportions of genes in a gene pool

what is a gene pool?

the total of all the genes in all the individuals of the population. Changes take place across generations

Since humans change.. do they undergo evolution?

humans undergo development and metamorphosis, not evolution.

how long does it take for evolution to occur?

shortest possible time in one generation. For evolutions of species/families usually 100s or 1000s of generations

what changes when a population undergoes evolution?

the frequency of alleles change- even if it is a small change in frequency

what can cause evolution to happen?

Mutation, migration/gene flow, random genetic drift

what is mutation?

ultimate source of genetic variation

what is migration/gene flow?

when a few individuals from one population interbreed with another population- introducing genes into a population

what is random genetic drift?

accidental events involving very small population shifts the frequencies of genes (volcanic eruption on a small population)

what must be present in a population in order for it to evolve?

genetic variation and phenotypic variation

what is genetic variation?

different forms of alleles- usually results in phenotypic variation

what is phenotypic variation?

must be genetically based

what is the evolutionary theory?

it is an organizing principle of science- not a hypothesis

what is the theory of common descent?

all life on Earth is descended from one ancestral population

difference between micro and macro evolution

micro- small changes in frequencies of genes in a population- takes millions of years



macro- evolution of new species, families and other major groups

what is the static earth hypothesis?

that the physical and biological nature of Earth remains unchanged over time

this hypothesis is based on two things

the scala nature and the great chain of being

what is the scala nature?

levels of fixed life forms

what is the great chain of being?

earth has to remain just as god created it- that means nature is unchanged

what is the principle of stratigraphy?

positioning of fossils- different layers

what is the theory of uniformity?

geological processes are continually changing the Earth

what is believed through the Lamackian evolution?

it is an inartistic drive toward perfection


- acquisition of characters through use and disuse


- inheritance of acquired characteristics

what is an example of Lamackian evolution?

the mud skipper uses its fins to move from puddle to puddle- eventually muscles become stronger

according to the theory of common descent, is their a common ancestor to all life on earth?

Yes. assuming that simple life only arose once from non-life

who do humans share ancestors with?

all- orangatans, gorillas, chimps, bonobos

what is homology?

refers to similarities among species or function that results from shared ancestry- same # of bones. same function

what is the static model?

species arise separately and do not change over time

what is transformation model?

species arise separately but change over time to adapt to changing environment

what is the separate types model?

species change over time, new species can arise, derive from a common ancestor

what are vestigial structures

those who appear to have greatly reduced function compared to similar structures in other species- no longer function as they once did

what is the theory of island biogeography?

distribution of organisms on Earth, especially on land- islands nearest to mainland