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14 Cards in this Set

  • Front
  • Back
fossil record
information about past life
relative dating
the age of a fossil is determined by comparing its placement with that of fossils in other layers of rock.
index fossil
used to compare the relative ages of fossils
half life
the length of time required for half of the radioactive atoms in a sample to decay
radioactive dating
is the use of half lives to determine the age of a sample
geologic time scale
used to represent evolutionary time
three periods of time between precambrian and present. they include: palezoic, mesozoic, and cenozoic.
proteinoid microspheres
tiny bubbles formed by large organic molecules
endosymbiotic theory
proposes that eukaryotic cells arose from living communities formed by prokaryotic organisms
large scale evolutionary changes that take place over lonf periods of time
adaptive radiation
studies of fossils show that a single species has evolved into several different forms that live in different ways
convergent evolution
unrelated organisms come to resemble one another
co evolution
two species evolve in respoce to changes in each other over time
punctuated evolution
pattern of long, stable periods interrupted by breif periods of more rapid changes