Georges Cuvier showed that the life of the past was not necessarily the same as that of the present.
Notes on verification
Multiple independent, high-quality sources (Britannica, UC Berkeley, NPS, Linda Hall Library) corroborate that Cuvier established extinction as a real phenomenon and demonstrated past life differed from present life, primarily via comparative anatomy of fossil vertebrates. [cascade flags: aggregator_dropped_primary_exists | tier=silver indep_score=0.95 clusters=3 claim_tier=notable]
Sources
- Paleontology (wikipedia)
- https://www.lindahall.org/about/news/scientist-of-the-day/georges-cuvier/ (corroboration)
- https://ucmp.berkeley.edu/history/cuvier.html (corroboration)
- https://www.nps.gov/articles/geologic-principles-organic-extinction.htm (corroboration)