19 terms

Ch 17 The History of Life

scientists who study fossils
fossil record
information about past life, including the structure or organisms, what they ate, what ate them, in what environment they lived, and the order in which they lived
term used to refer to a species from all parts of its geographical range
relative dating
method of determining the age of a fossil by comparing its placement whi that of fossils in other layers of rock
index fossil
distinctive fossil used to compare the relative ages of fossils
length of time reuired for half of the radioactive atoms in a sample to decay
radioactive dating
technique in which scientists calculate the age of a sample based on the amount of remaining radioactive isotopes it contains
geologic time scale
scale used by paleontologists to represent evolutionary time
one of several subdivisions of the time between the Precambrian and the present
unit of time into which eras are subdivided
large-scale evolutionary patterns and processes that occur over long periods of time
mass extinction
event in which many types of living things become extinct at the same time
endosymbiotic theory
theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms
microscopic fossil
proteinoid microsphere
Tiny bubble, formed of large organic molecule, that has some characteristics of a cell
adaptive radiation
process by which a single species or small group of species evolves into several different forms that live in different ways; rapid growth in the diversity of a group of organisms
convergent evolution
process by which unrelated organisms independently evolve similarities when adapting to similar environments
process by which two species evolve in response to changes in each other
punctuated equilibrium
pattern of evolution in which long stable period are interrupted by brief periods of more rapid change