Lecture 33: Tempo & Mode Flashcards
Define tempo
rate and any modulation thereof
morphological rates of evolution
- change in character/unit
Define mode
particular manner or form
Passive vs. Driven trends of evolution
Passive Process - tends to have an increase in mean but the smallest starting point will not be passes
Driven - increase in mean and smallest passes
Understand the affect environment can have an tempo
- corn
- those fish whose habitat wasn’t changed
What are taxonomic rates of evolution?
- Number of taxa originating per unit time
- Average number of years a taxon stays extant
What is Simpson’s taxonomic survivorship data?
- records first and last appearance
- can be used to plot survivorship curves
What are the different modes of evolution?
- Phyletic gradualism
- Punctuated equilibrium
- “rectangular” evolution
What is phyletic gradualism?
- slow, gradual change in phenotype
- speciation by gradual change
What is punctuated equilibrium?
- periods of little or no change are, “punctuated” by rapid morphological change
- most morphological change is at speciation
(the bulk of the evolution happens at the speciation event)
There are lineage-specific rate of…?
- Speciation
- Extinction
Species with _____ ranges persist longer and have lower extinction rates
wider
- extinction negatively correlated with number of times found in fossil records