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Jean-Baptiste Lamarck
1744–1829; Philosophie zoologique, 1809· Scientist· Animals
Well establishedStrong fossil, genetic or geological evidence.
French naturalist who proposed the first full theory of evolution, though by a mechanism later largely rejected.
See it on the Life map →What happened
Jean-Baptiste Lamarck, a botanist turned expert on invertebrates (a word he coined), proposed from 1800, most fully in 1809, that species slowly change into new ones. He saw two drivers: a natural tendency toward complexity, and habits. Organs used more grow stronger, unused ones dwindle, and such acquired changes pass to offspring; his example was giraffes stretching for leaves. He also helped popularize the word 'biology'.
Why it matters
He made evolution a serious scientific idea fifty years before Darwin, though his main mechanism, inheritance of acquired traits, turned out to be largely wrong.
Discoveries and legacy
Philosophie zoologique (1809) and his volumes on invertebrates survive; Cuvier's mocking eulogy shaped his poor reputation. He died poor and blind in 1829.
Still debated
How far epigenetics, chemical tags on DNA that can sometimes pass to offspring, revives any part of his ideas; most biologists say very little.
Connections (2)
▸Jean-Baptiste Lamarck proposed an earlier rival to Evolution by natural selectionWell established
The connection
Lamarck's 1809 Philosophie zoologique offered the first full theory that species change over time. His mechanism differed: organisms change through use and disuse of body parts and pass those acquired traits on, driven by a tendency toward complexity. Darwin proposed selection instead, though he too accepted some inheritance of acquired traits.
When and how
Paris, at the National Museum of Natural History, 1800–1809; August Weismann's germ-line theory of the 1880s argued that acquired traits are not inherited.
The evidence
Weismann cut the tails off mice for generations without producing tailless offspring, and genetics later found no general route from body changes to eggs or sperm.
Debates and open questions
Epigenetics, chemical tags on DNA, can sometimes pass environmental effects to offspring for a few generations; how much this matters in evolution is debated.
▸Georges Cuvier opposed the evolution ideas of Jean-Baptiste LamarckWell established
The connection
Lamarck and Cuvier were colleagues at Paris's natural history museum but rivals in ideas. Lamarck argued species gradually transform; Cuvier insisted species were fixed and that extinct ones were wiped out, not transformed. He cited mummified Egyptian animals, unchanged over thousands of years, as evidence. His mocking eulogy of Lamarck damaged Lamarck's reputation for decades.
When and how
Paris, National Museum of Natural History, roughly 1800–1832; Lamarck's evolution ideas from 1800 and Philosophie zoologique in 1809.
The evidence
Their published works and lectures survive, including Cuvier's Researches on Fossil Bones (1812) and his eulogy of Lamarck, read in 1832 and published in 1835.
Debates and open questions
How much Cuvier's authority delayed acceptance of evolution in France, and whether his mummy argument was fair, since a few thousand years is too short for visible change.