The Theory of Evolution by Natural Selection (HSC SSCE Biology): Flashcards
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Gradualism definition
Gradualism definition
Slow, continuous evolutionary change over time
Punctuated equilibrium definition
Punctuated equilibrium definition
Rapid bursts of change, then long stable periods (stasis)
Scientist who proposed gradualism
Scientist who proposed gradualism
Charles Darwin
Scientists who developed punctuated equilibrium (1970s)
Scientists who developed punctuated equilibrium (1970s)
Stephen Jay Gould and Niles Eldridge
Fossil evidence for gradualism
Fossil evidence for gradualism
Trilobites (slow, continuous change)
Fossil evidence for punctuated equilibrium
Fossil evidence for punctuated equilibrium
Horseshoe crabs (unchanged for 445 million years)
Expected in gradualism fossil record
Expected in gradualism fossil record
Intermediate or transitional forms
Stasis in punctuated equilibrium
Stasis in punctuated equilibrium
Long periods with populations stable, little change
Do both models challenge natural selection?
Do both models challenge natural selection?
No, both accept natural selection as the mechanism
Macroevolution meaning
Macroevolution meaning
Large-scale evolutionary changes