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25 Cards in this Set

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evolution
change in the herediatry features of a species over time
what is a species?
group of organisms whose members successfully mate & have fertile offspring
what is a population?
organisms of one species who live in the same place at the same time
what was Lamark's hypothesis
Jean Baptiste Lamark's hypothesis stated that aquired characteristics could be passed on to offspring
what was lamark's example?
giraffes started out w/ short necks & then aquired long necks
what was the problem with his theory?
his hypothesis was never tested by Lamark & evenutally others disproved it
what was charles darwins theory?
said that organisms w/ traits most favorable for their environment sruvived & passed these traits on to their offspring

*tested and is evoltion*
what is natural selection?
tje process by which nature selects organisms best adapted 2 a given environment @ a particular time
theory of evolution by natural selection
variations exist within a species & these variations can be passed from generation to generation
limiting factor
any physical or biological factor that regulates the welfare of an organism
explain the gradual chart
things change gradually
a species might take thousands of years to change color, which is gradual evolution
explain the punctuated evolution chart
periods of stability followed by periods of rapid change

things (changes) happen almost instantly
what are the different types of fossils
imprint
mold
cast
petrifed
what is an imprint?
formed by tiny bones, leaf veins, feathers as the soft part of decompose
*when you put your hand in wet cement to make a print that's an imprint*
what is a mold?
formed by impressions of large bones that decompose leaving a negative space where the bone used to be
*when you take something out of cement the part left behind is the mold*
what is a cast?
formed when the space left behind a mold is filled with minerals and sediment
*looks like the original bone*
what is petrified?
formed when minerals replace decomposing tissue leaving a perfect replica of the organism in stone
*a rock that was once a living tree*
what is relative age?
position of the fossil in the rock layers (stratum) indicates its age relative to other fossils found
what is absolute age?
actual age of the fossil determined by radiocative dating
which is more accurate radioactive or relative dating?
radioactive dating is more accurate (exact)
what is a fossil?
traces of dead organisms found in sedimentary rock
sedimentary rock is layers of sediment compacted to make a rock
why did ppl used 2 believe that species never changed?
during human lifetime it appears that species do not change. scientists began to suspect that species do chang SLOWLY
took many years for scientists to discover evolution
who was charles darwin?
he was a captains boy on the HMS
he observed & noted everything & created a detailed catolague. he collected plant animal & fossil specimens
was charles darwins observations accurate?
no because he took bad notes
he didnt write down where and when he saw things (he wasnt specific enough)
what is a naturalist?
someone who studies nature