Life Responds to a Changing Earth
Source Institution: Smithsonian National Museum of Natural History
Source Exhibit: David H. Koch Hall of Fossils - Deep Time
Source Url: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list
Source Kind: interpretive_topic_or_panel
Use: research inspiration only; SAGE will write original interpretation
Dossier Status: scientifically_enriched_concept_room_10
Plain Language Explanation: Life does not evolve on an unchanging planet. Climate, sea level, tectonics, ocean circulation and atmospheric chemistry continually alter habitats. Populations may shift their ranges, adapt across generations, split into new lineages or disappear. After the end-Cretaceous extinction, surviving mammals diversified into ecological roles that had been transformed by extinction and by later changes in climate and geography.
Evidence: The Cenozoic fossil record documents repeated changes in mammal communities as climate and vegetation changed.; Smithsonian Deep Time contrasts early Cenozoic rainforest ecosystems with later open grassland ecosystems.; Fossils record lineages appearing in new regions when geographic barriers changed.
Examples From Collection: Eohippus vasacciense; Hesperocyon gregarius; Moropus elatus; Mammuthus primigenius; Bison priscus
Common Misconception: Environmental change does not automatically make organisms evolve the traits they need. Evolution depends on inherited variation, population processes and survival or reproduction across generations.
What Scientists Still Debate: For individual fossil lineages, researchers continue to separate the effects of climate, competition, geography, ecological opportunity and chance.
Sources: https://www.si.edu/newsdesk/factsheets/david-h-koch-hall-fossils-deep-time; https://humanorigins.si.edu/research/climate-and-human-evolution/climate-effects-human-evolution; https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list
Enrichment Method: SAGE original interpretive concept; natural Earth-system change separated from human-driven change; migration, body size, ecosystem reconstruction and human impacts tied to explicit evidence and uncertainty