Biology 3484A/B Lecture Notes - Lecture 8: Allopatric Speciation, Extinction Debt, Continental Drift
24 Mar 2018
School
Department
Course
Professor
Document Summary
Species diversity: species diversity the result of gain (speciation) and loss (extinction) of species combination. Cretaceous: there is debate about the capitanian period extinction event (but it gets combined) Ordovician period: 488-443 mya first major extinction event, sea levels were high, and most land was found south of the equator (gondwana was the major. Life was mostly in the sea continent here: marine life dominated by invertebrates, also had primitive fishes, the first land plants appeared towards the end of the ordovician. In this period, life started to appear on land and plants on shore (and water continued too) reef species: therefore, in this period, we can point out some biotic actions (species) that causes extinction of other species. Permian period long period until this extinction event occurred: 299-251 mya (pangaea had formed, this was an opportunity for all land life to move around the continent.
