evolution lecture 6

Question 1

What is systematics?

Answer 1

study of the diversity of life

Question 2

what are the two components to systematics?

Answer 2

• taxonomy

- phylogenetics

Question 3

taxonomy

Answer 3

naming and identification of taxa

Question 4

phylogenetics

Answer 4

estimation of evolutionary trees

Question 5

most biologists today consider taxonomy to relefct____

Answer 5

phylogeny

Question 6

cladogram vs phylogram

Answer 6

cladogram: branch lengths have no meaning
phylogram: branch lengths represent amount of evolutionary change

Question 7

monopheltic group

Answer 7

and ancestor and all of its descendants

Question 8

paraphyletic group

Answer 8

and ancestor and some of its descendants

Question 9

polyphetic group

Answer 9

a group that does not include its own most recent ancestor

Question 10

how do we infer phylogenies?

Answer 10

• CHARACTER STATES (possible homologies)
  - morphological features… ect )
  - identities in DNA/ protein sequences
• DISTRIBUTION of character states among organisms reflect evolutionary relationships

Question 11

cladistic reasoning

Answer 11

shared derived – imply relationships

shared ancestral states – do not imply relationships

Question 12

What if character state distributions NOT all consistent with the same tree?

Answer 12

it's due to: 
    convergent evolution
    reversals
one method: parsiomy 
- compare all trees 
- best inference is tree that has fewest evolutionary changes

Question 13

phylogenies of genes

Answer 13

• evolution of genes themselves often of interest

- one of many aspects of the dicsiplines of molecular and genome evolution

Question 14

lateral and horizontal gene transfer?

Answer 14

• transfer of genes between species

- quite common in unicellular organisms