Update
Evolution devolution
Evolutionary evidence
More evidence
Mapping plants
Time line
History of a dispute
Evolution solution
The Ancient Debate.
A long-playing story
12 billion years ago
Universe forms during Big Bang
4.5 billion years ago
Earth coalesces from hot gas and dust
About 3 billion years ago
First living organisms
About 600 million years ago
First multi-cellular organisms
65 million years ago
Dinosaurs meet their doom
About 1800
French biologist Jean Baptiste de Lamarck says organisms change by adapting to their environment. These "acquired characteristics," he says, are then inherited: giraffes' necks are long because they must reach for their food.
1817
French naturalist Georges Cuvier proposes that floods and other catastrophes divide the geologic record into distinct eras where different kinds of organisms lived. He figures that since fossils from upper layers ("strata") of rocks are closer to today's life than those in lower strata, lower rocks are older, and contain older organisms.
1859
Charles Darwin, in "The Origin of Species," and Alfred Russell Wallace, both propose theories of evolution through natural selection. Organisms that are better suited to the environment are more likely to survive and reproduce, forcing species to change, or evolve.
Late 1800s
Evolution -- the change of organisms through time -- gains acceptance among scientists, but many assume that God directed the changes. Some scientists hold Lamarck's view -- that new features are acquired rather than gained through natural selection.
1900-1945
Social Darwinism, the notion that unbridled competition allows the "best" people to rise to the top, and eugenics, a drive to "improve" people through breeding, result in scientific racism and are used to justify Nazi atrocities.
1920s
Modern view of evolution develops: random mutations occur among organisms, and those that survive natural selection are represented in later generations. Fossil evidence shows gradual change and development of organisms in both plant and animal realms.
1925
John Scopes, a Tennessee high school teacher, is convicted for teaching evolution in the classroom (see "Inherit the Wind and Summer for the Gods" in the bibliography).
1953
Francis Crick and James Watson discover the double-helix structure of DNA, unlocking heredity's "memory storage" mechanism.
1967
Tennessee repeals "monkey law" under which Scopes was convicted.
1982
Pollster George Gallup finds that about 50 percent of the U.S. population believes in strict creationism.
1980s to present
Analysis of DNA and RNA is used to map the tree of life. Resurgence of creationism among religious fundamentalists renews pressure on biology teachers.
1999
Kansas school board removes teaching of evolution and cosmology from required high-school science curriculum and testing.
