Lecture 35: Extinction Flashcards
Define extinction
termination of a lineage
What is the pattern of lineage extinction?
Chances are very high that a lineage will go extinct over a long time.
What is the Red Queen Hypothesis and what does it apply to?
Organism have to “run to stay in place”, applies to the coevolutionary “arms raced” and to extinction.
What does the linearity of taxonomic survivorship curves suggest?
The approximate linearity of the polts suggests that the probability of extinction is independent of the age of a taxon.
What are taxonomic survivorship curves?
The plot the log of # of taxa surviving for a prescribed period of time.
The slope of the line = probability of going extinct in that time interval.
(constant probability of going extinct)
Define mass extinction
> 60% of living species go extinct within 1 million years
What is “The Big Five”?
Refers to the big 5 mass extinction events.
Define background extinction
extinctions that are not part of mass extinction event; thought to be due to typical types and rates of environmental change or species interactions as opposed to the extraordinary environmental changes that occur during mass extinction.
What is the K-T Boundary?
Boundary between Tertiary and Cretaceous periods.
- spike of iridium
What is the Chicxulub Crater?
Crater that hit the tip of the Yucatan Peninsula
Global “winter’
Characterized by vaporization of seawater and mineral deposits
Cooling affected large-bodied organisms
What is the 6th mass extinction?
Human Impact
Extinction of dinosaurs
- Asteroid Impact
- Diversity shows other factors might have been in play
Define dinosaurs
Mesozoic reptiles with pillared legs
What are the 2 kinds of dinosaurs?
Saurischians (lizard hipped) and Ornithiscians (bird hipped).
