Phylogenetics

Question 1

Phylogenetic Tree

Answer 1

diagram representing the branching history of evolution

Question 2

Common ancestor

Answer 2

population found at branching points, which gives rise to all descendant species

Question 3

Tips

Answer 3

extant, sometimes extinct, organisms being compared

Question 4

Branches

Answer 4

independently evolving lineages; could contain many species

Question 5

Nodes

Answer 5

branching points; represents populations not individuals

Question 6

Clades

Answer 6

all branches and tips derived from a given node

Question 7

Most Recent Common Ancestor (mrca)

Answer 7

nearest node joining a clade together

Question 8

Root

Answer 8

extra node added at the base–>mrca for all organisms on the tree

Question 9

Sister Taxa/clades

Answer 9

two taxa or clades which share a common ancestor, all individuals of one sister clade are equally related to all individuals in their sister clade

Question 10

Phylogenetic Inferences

Answer 10

1. Data
2. Possible Trees
3. Map Characters
4. Evaluate Trees

Question 11

Principle of Parsimony

Answer 11

simplest solution which explains all data

Question 12

Maximum Parsimony

Answer 12

criterion which says the best tree is the one which requires the fewest evolutionary changes for all characters

Question 13

Applications of Phylogenetics

Answer 13

1. inferring evolutionary relationships
2. framework for understanding and testing patterns of evolution
3. classification and identification of species
4. forensics
5. others: determining when in history events occurred, making inferences about characteristics of extinct species

Question 14

Homologous Structures

Answer 14

structures which evolved from the same feature in a common ancestor

Question 15

Homoplasious Structures

Answer 15

structures which are similar in form and function that arose independently

Question 16

Convergent Evolution

Answer 16

do not arise from the same structure in their common ancestor; occurs when similar selective pressures act along two independent branches

Question 17

Taxonomy

Answer 17

classifying and naming organisms

Question 18

Phylogeny

Answer 18

reconstruction of evolutionary relationships via trees

Question 19

Cladistics

Answer 19

1. Monophyletic
2. Paraphyletic
3. Polyphyletic

Question 20

Monophyletic

Answer 20

groups reflect common ancestry and evol. history; clade

Question 21

Paraphyletic

Answer 21

a group of organisms descended from a common evolutionary ancestor or ancestral group, but not including all the descendant groups

Question 22

Polyphyletic

Answer 22

a group of organisms derived from more than one common evolutionary ancestor or ancestral group and therefore not suitable for placing in the same taxon