Lect 7- Inferring Phylogenies

Question 1

Parsimony

Answer 1

keep as simple as possible

ex: phylogeny with fewest events

Question 2

Two ways to construct a Phylogeny

Answer 2

Morphological - assume homologus- trait due to decent from common ancestor

DNA- use a portion of a gene present in all spp -homology determined by sequence alignment

Question 3

Why are rooted trees important?

Answer 3

direction of evolutionary change can be inferred

ex: black vs yellow billed mag pies - can tell dispersal and speciation
ex: HIV transmission

Question 4

How can you construct a phylogeny of microbes or all orgs?

Answer 4

find genes that are present in all orgs
functions are essential and have remained the same
(strong stabilization selection, no rapid divergence)
use ribosomal DNA

Question 5

Dr. Carl Woese

Answer 5

Used ribosomal DNA to construct tree of life with three branches: bacteria, eukaryota, archea

Question 6

Anoles

Answer 6

lizzards in Caribbean that are ecomorphs
-ea spp lives on different part of tree and this is found throughout multiple islands. Via DNA, they dispersed to islands, then became ecomorphs. Convergent evolution!