Palaeobiodiversity Flashcards
How can the biodiversity of extant organisms be measured?
- Examine rate of discovery cues
- Extrapolate from intensive local sampling
How can the biodiversity of fossil organisms be measured?
At prescribed intervals of time measure:
- Morphological diversity
- Number of taxa
How can measuring the biodiversity of fossil organisms be hard?
Hard to measure because the fossil record is incomplete and biased.
Can’t recognise species, sexual dimorphism, diseased individuals etc.
What percentage of species that have ever lived are represented by extant species?
2-4%
Do plants and animals suffer mass extinctions the same?
No, plants do not suffer mass extinctions as much as animals because they have different reproductive strategies.
Do actual patterns of diversification follow theoretical models?
No
How much more diverse is life on land to oceans?
5-6 times
What percentage of all described fossils are marine?
Why?
95%
The ocean is a constant environment, land is not.
What are 2 models that can explain patterns of biodiversity?
- Equilibrium model: biodiversity ceiling due to limiting factors, e.g. carrying capacity
- Expansion model: no biodiversity ceiling, things keep diversifying until mass extinction.
What was the proposed theory of dinosaur biodiversity?
That there was an exponential increase of biodiversity of dinosaurs, they kept evolving new innovations and behavioural strategies.
What percentage of dinosaur genera was unknown in 2006?
71%
What was the actual theory of dinosaur biodiversity?
Dinosaur biodiversity started falling at the end of the Cretaceous.
If rock volume is taken into account, it was realised that the supposed increase did not happen.
It is supposed there was an equal rate
What is the pull of the recent?
Old rocks are more likely to be destroyed than new rocks up the rock column.
