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James' Stack

Chapter 6 Changes Over TIme

Natural Selection The process by which individuals are better adpated to their environment and are more likely to survive and reproduce.
Variations Any differebce between individuals of the same species.
Half Life The time it takes for half of the atoms in a sample to decay.
Scientific Theory A well tested concept that explains a wide range of observations.
Punctuated Equilibrium Theory The theory that species evolve quickly during short burts of time.
Fossil Record Documentation of the millions of fossils scientists have collected over time.
Radio-Active Element Unstable elements that decay or break down into different elements.
Homologous Structures Similar structures that related species have inherited from common ancestors.
Mold A hollow space left where the fossil has decayed of dissolved.
Relative Dating A process comparing the age of two fossils by their placement in the layers of sedimentary rock.
Pretrified Fossils Fossils that are buried in sediments and actually changed to rock.
Adaptation A trait that helps an organism survive and reproduce.
Gradualism Theory The theory that evolution occurs slowly but steadily.
Branching Tree A diagram that shows whow scientists think different groups of organisms are related.
Radioactive Dating/Absolute Dating A process that tests the radioactive materials within a fossil to tell its actual age.
Fossil Preserved remains of an organism that lived in the past.
Extinction When no member of the species is still alive.
Cast A copy of the shape of the organism that made.
Competition This is a factor in Natural Selection as organisms attempt to survive using the same limited resources.
Homologous Structures Evidence that related species had a common ancestor because of the way their bodies anatomically constructed in similar ways.
Over Production This factor in Natural Selection happens when there are move offspri g than can possibly survive on the given resources.
Species A group of organisms that can mate together and produce fertile offspring.
Created by: 22jhagman