CH20 Phylogenies/ Taxonomy

Question 1

All living org. share one or more characteristic…(4)

Answer 1

1. One or more cells
2. Metabolism
3. E transfer w/ ATP
4. Herditary info. transferred in DNA

Question 2

Ways to identify groups w/ shared characteristics; (6)

Answer 2

1. fossils
2. morphology
3. physiology
4. behavior
5. embryo development
6. DNA/ RNA sequences

Question 3

Systematics

Answer 3

reconstruction and study of evolutionary relationships

Question 4

Phylogeny

Answer 4

hypothesis about relationship between taxonomic groups

Question 5

Rooted Cladogram

Answer 5

single lineage represents common ancestor

Question 6

Unrooted

Answer 6

…

Question 7

Taxon

Answer 7

groups of organisms

Question 8

Clade

Answer 8

Any branch of lineage from a common ancestor

Question 9

Branch point aka

Answer 9

node

Question 10

Node;

Answer 10

splitting represents single lineage evolving into 2 clades

Question 11

Limitations of phylogenic tree (2)

Answer 11

1. taxa may not always look similar

2. if evolved under different circumstances, taxa look very different

Question 12

Binomial Nomenclature

Answer 12

Genus (capitalized) + epithet

entire name is italicized

Question 13

Homologous characteristics

Answer 13

traits derived from a common ancestor

• More complex traits, more likely of the same origin)
  ex. humerus, phalanges in humans, birds and whales)

Question 14

Analogous Traits

Answer 14

similar due to ecological pressure, no common ancestor

birds and insects having wings

Question 15

Evolutionary reversal

Answer 15

similar analogous traits lead taxa to appear related, when they are not **

Question 16

Convergent Evolution

Answer 16

2 separate groups w/ same environmental pressures lead to similarities (ex. birds and insects having wings)

Question 17

Molecular comparieson

Answer 17

most accurate way to discern relationships (DNA / RNA sequences )

Question 18

Why phylogenies matter?

Answer 18

1. evolutionary process
2. insight into human health, medical advances- drugs!
3. track parasite/ virus evolution
4. BioTech. for GM crops
5. conservation efforts for endangered species

Question 19

Cladistics

Answer 19

Process to arrange taxa by homologous traits into clades

Question 20

descent w/ modification

Answer 20

org. taxa evolved from common ancestors, then diversify

- Change in genetic makeup leads to new trait which may be advantageous, thus passed along

Question 21

Evolution doesn’t lead to perfection

Answer 21

• many random mutations lead to new traits (good/bad / neutral)

Question 22

Shared ancestral trait

Answer 22

2 + on cladogram have same traits (ex. hair or legs etc.)

Question 23

Rule of Parsimony

Answer 23

choose the simplest cladogram w/ fewest steps or events

Question 24

Biological Species Concept

Answer 24

define species as groups of interbreeding populations reproductively isolated

Question 25

How to eukaryotes evolve?

Answer 25

cell membrane surrounds nucleotide, creating endomembrane system, creating mitochondria & chloroplasts