BI111 Chapter Notes - Chapter 72: Proterozoic, Phanerozoic, Cenozoic
Document Summary
Chapter 75: change in species over geological time. Evoln from earliest single-celled life forms to complex organism. Fossil records proved pace of evoln varies. Geological isolation can cause speciation events to occur faster mass extinction events: catastrophes that hit earth fast, wiping out 75% of species on planet. Lots of fossil records of leaves, pollen, flowers, wood- those that display taxonomic characteristics of modern tropical plant group- indicates frozen landscape seen today was once subtropical eon: very long time. Factors that contribute to trends in species diversification over time. Species diversify when they become isolated (preventing gene flow) Extinction events left ecological niches open, thus followed by adaptive radiations =new species. Continental drift influenced climate, changed position of continents relative to equator. Lead to allopatric speciation; speciation occurs result of physically being isolated. Dominant group anaerobic prokaryotes flourished & diversified but gone when envio changed. Global warming (glacial melting, flooding, falling o2 levels), global cooling,
