Update
Evolution devolution
Evolutionary evidence
More evidence
Mapping plants
Time line
History of a dispute
Evolution solution

Evolution quiz

Evolution!

 

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.

The Ancient Debate.


back more
The Why Files

There are Update 1 2 3 4 5 6 7 pages in this feature.

Bibliography | Quiz | Credits | Feedback | Search

©1999, University of Wisconsin, Board of Regents.