Fossils and molecular revolution Flashcards
1
Q
Why is DNA difficult to preserve?
A
- Easily contaminated (infested with microbes)
- Dna breaks down very quickly in the presence of water and/or air
2
Q
Huge advances of studying ancient dna.
A
- Sequencing strands of dna
- Input in a computer which stitches together whole genomes.
- Woolly mammoth entire dna sequence
- Entire neanderthals genome sequenced
- No dinosaur DNA yet - protein has been derived from collagen
3
Q
Molecular taxonomy
A
- Cladistic analysis on characteristics doesn’t account for simplicity due to loss.
- Bryophyte (diverse ancient plants): basal ones were more complex and simple ones had lost morphology due to lack of need
- Reduction due to function
4
Q
Diversification of birds
A
Bird fossils are rare in the jurassic and cretaceous
- Skies rules by pterosaurs
- More shore birds preserved
KT bolide impact and mass extinction
- Pterosaurs go extinct
- Birds survive and diversify
5
Q
What are the two theories for when birds evolved and diversified?
A
- Neognathae evolved after the KT mass extiction and filled ecological vaccum left by pterosaur extinction?
- Neonathe have long cretaceous hostory but they were rare and not very diverse
6
Q
Developmental genetics
A
Hox gene duplication events
Shifting zones of hox gene expression
7
Q
What does evo-devo studies allow us to do?
A
Manipulate genes and see how they were passed on and evolved
