Phylogeny

Question 1

Phylogenetic trees

Answer 1

Branching of lineages indicated evolution

Question 2

Node

Answer 2

Where branches split

Question 3

Branches

Answer 3

Where evolution occurs

Question 4

Endpoint tips

Answer 4

Observed taxa

Question 5

Monophyletic group (aka _____)

Answer 5

Single shared ancestor and ALL descendants

When counting: count tips and EVERYTHING

aka clade / taxa

Question 6

Sister taxa

Answer 6

Share a common node

Question 7

Types of characteristics

Answer 7

Morphological (aka physical) or genetic

Question 8

Phenetic vs cladistic analyses

Answer 8

Phenetic - physical attributes

Cladistic (phylogenetic) - evolutionary relationships

Question 9

When to use morphological analysis

Answer 9

• when genetic info isn’t available

ex. fossils
viruses that evolve very quickly

Question 10

Synapomorphies

Answer 10

Shared derived characteristics

• Tree must explain them

Question 11

Basal characteristics (aka ____)

Answer 11

aka ancestral characteristics
The common ancestor had the same characteristics

Question 12

Derived characteristics

Answer 12

Evolved characteristic (derived) not shared by a common ancestor

Question 13

Outgroup

Answer 13

Organism closely related to the group being studied but not in the group

Question 14

Root

Answer 14

Beginning of the phylogenetic tree

Question 15

Convergent evolution + what is this an example of?

Answer 15

Two species evolve the same trait independently

It’s an analogy, similarities not due to homology (common ancestry)

Question 16

Secondary loss

Answer 16

Losing a trait your ancestor had

Question 17

Parsimony

Answer 17

Simplest answer/explanation = fewest changes needed

Question 18

Bacteria, archaea, eukarya

Answer 18

B: no nuclei, small, most micro-organisms

A: no nuclei, small, extreme environments

BA both chemoautotrophs

E: large, have nuclei

Question 19

Reuniting examples

Answer 19

Hybridization and allopolyploidy (organism has chromosomes from 2 diff. species)

Question 20

Why might there be more fossils of some species rather than others?

Answer 20

• Environment (swampy/marine = sediment movement to bury them)
• Hard parts last longer
• Recent ancestors (easier to find, less dissolved)
• More abundant species

Question 21

Radiation events

Answer 21

Result in dramatic diversification

Question 22

Mass extinction

Answer 22

Result in loss of species (maybe)

Question 23

Adaptive radiation

Answer 23

Single lineage produces many descendant species in a short period of time

Question 24

Ecological opportunity

Answer 24

• Organism arrives in an area with no similar organisms
• Competing species extinction

Question 25

Morphological innovation

Answer 25

A new adaptive mutation = opportunities for further adaptation
- ex. legs, multi-cellularity, flowering plants

Question 26

Co-evolution

Answer 26

Evolution in one group creates new niches for another group
- ex. insects and flowering plants

Question 27

Gene duplication

Answer 27

Genes / chromosomes duplicated

ex. polyploidy

Question 28

How many mass extinctions so far

Answer 28

5