Homologous Trait (homology)
Trait shared by common ancestor
Analogous Trait (analogy)
Trait with no common ancestor (tied to convergent evolution)
Convergent Evolution
Species that evolve independently to have the same phenotype
Parsimony
Simplest hypothesis
Monophyletic:
Common ancestor in all descendants
Important to remember
Nodes can swivel!
Paraphyletic:
Common ancestor and some of the descendants
Polyphyletic:
No common ancestor
LUCA
Last universal common ancestor
What evidence supports a LUCA?
- Central Dogma
- Lipids
- Enzymes
- Genetic Code: similar nucleotides and proteins
What is the RNA World Concept?
The theory that RNA was the basic molecule used for basic functions in a cell. Acted as both DNA and proteins.
What are the three hypotheses for the origin of life?
1 Deep sea thermal vents
What was needed to start the origin of life?
All require surface and energy.
What is the Darwinian Threshold Hypothesis?
The shift from having mainly horizontal gene transfer to vertical gene transfer.
How have CO2 and O2 levels changed on Earth through time?
Beginning: High CO2, little to no O2
Today: Low CO2, high O2
