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Nat Selection
Question | Answer |
---|---|
a group of organisms that share similiar characteristics | species |
can reproduce among themselves and produce fertile offspring | species |
changes in inherited characteristics over time | evolution |
studied finches on Galapagos island, Found they were all similiar to one type of finch | Darwin |
Believed the finches changed as they competed for food | Darwin |
organisms with traits best suited for the environment survive and reproduce. Traits are passed on to offspring. Unfavorable traits die off with offspring that do not survive | natural selection |
inherited trait that makes an individual different from other members of its species | variation |
can come from mutations | variation |
beneficial mutations are more likely to be passed on due to natural selection | variation |
changes in species can take a long time to appear | variation |
changes can appear when members of same species move into or out of an area | variation |
if small number of individuals are isolated from others variation may appear in one population that are not present in the other | variation |
populations can become so different due to this that they become 2 different species and can no longer breed | variation |
variation that increases an organism's chance for survival | adaptation |
slow process where one species changes into another | gradualism |
rapid evolution occurs when individuals mutate and pass on those mutations/traits | punctuated equilibrium |
when bacteria becomes resistant to antibiotics this is happening | punctuated equilibrium |
remains or traces of once living organism | fossil |
usually found in sedimentary rock | fossil |
carbon that is left after organism decays; can harden to rock | imprint |
sediments fill cavity left by decaying organism's and this is formed | cast |
impression of the shape or track of an organism | mold |
an estimate about the age of a fossil based on the location in the rock | relative dating |
amount of time it takes for 1/2 of radioactive material to decay | radiometric dating |
This is used to determine a fossils age b/c radioactive material is unstable and decays at a set rate | radiometric dating |
More accurate for determining the fossil age | radiometric dating |
Carbon-14 has a half-life for how long? | about 5,700 years |
If a fossil has decayed through 3 C-14 half-lives (5700 years each), how old is the fossil? | 17,100 years |
If a fossil originally has 100 grams of C-14 and now has 25 grams, how old is the fossil? | 11,400 years |