Topic 7 - Systematics

Question 1

Define Systematics

Answer 1

The science of classifying organisms and determining their evolutionary relationship

Question 2

Define taxonomy and phylogentics

Answer 2

Taxonomy
- The science disciple on naming / classifying organisms

Phylogentics
- The study of evolutionary relationships

Question 3

What is the format for linnean nomenclature?

Answer 3

Format
- Genus, Species (eg. Homo sapiens)

Question 4

Homologous vs. Analogous and how it can evolve

Answer 4

Homologous
- Similarities due to shared ancestry

Analogous
- Similarities due to shared environments and not ancestry

How analogous traits evolve
- Can evolve through similar environmental hurdles species must survive, possible after a large scale extinction

Question 5

What are the basic principles of cladistics?

Answer 5

• Uses homologies to define clades
• Monophyletic

Question 6

How are morphology and molecular data used in the construction of phylogenetic trees?

Answer 6

• Sequence in nucleotides of the genes are more reliable in determining relatedness than relying purely on morphology

Question 7

Ingroups vs. Outgroups

Answer 7

Ingroups
- The group of interest

Outgroups
- One or more species outside the group of interest

Question 8

Shared derived traits vs. Shared ancestral raits

Answer 8

Derived
- Present in all of a group but absent in the common ancestor

Ancestral
- Present in all of a group and the common ancestor

Question 9

What is parsimony?

Answer 9

• Most likely tree is the one that involves the fewest number of evolutionary transitions

Question 10

Cladogram vs. Phylogram

Answer 10

Cladogram
- Show only the branching pattern with no other info

Phylogram
- Shows branching pattern and length is proportional to time

Question 11

What are the two methods for dating?

Answer 11

Molecular clock
- Assumes rate of nucleotide substitutions per unit of time is roughly constant

Fossils
- Radiometric / Stratigraphy

Question 12

Phylogenetic tree terminology?

Answer 12

Polyphyletic
- Random ass group

Monophyletic
- Group with common ancestor and all descendants

Paraphyletic
- Common ancestor but not all descendants

Question 13

What is a phylogenetic tree?

Answer 13

• A diagrammatic hypothesis of the evolutionary relationship of a group of organisms