III) The Role of the systematist (Phylo Class)

Question 1

What is comparative anatomy and what does it use?

Answer 1

• Comparasin of organisms skeletons and morphologies using homologies.

Question 2

What is a homology? give examples

Answer 2

Similar structures in different organisms when thought to have the same evolutionary origins, although their functions may differ.

Ex: human bones relating to bat wings.

Question 3

What is an anology? give example

Answer 3

features with similar functions that have developed independently in unrelated taxa groups in response to similar enviornments. Based on similarity, not relationships. (not based on tree)

Ex: bird wings vs insect wings.

Question 4

What are relationships of taxa based on?

Answer 4

Shared homologies.

Question 5

What is homoplasy? give ex

Answer 5

organism structures that are not inherted from CA but due to convergence. (Based on tree)

Ex: bird wings and dinosaur wings.

Question 6

Define ontogeny

Answer 6

Study of embryonic development of organisms, as the Ancestral characteristics are preserved there.

Question 7

What is the role of the systematist and what three methods do they use?

Answer 7

They search for relationships between organisms.

1) Comparative anatomy
2) Ontogeny
3) Paleontology

Question 8

Define Character and Character State

Answer 8

Character is the observable feature of an organism. Character state is the variability of character, such as eye color.

Question 9

What are the three main phylogenetic methods to compare character state and what are they used for mainly?

Answer 9

1) Cladistics (large data sets including morpho characters, with focus on evolutionary pathways)

2) phenetics (includes as many variables as possible; quantitative methods based on distance)

3) molecular methods ( Same as cladistics but on the molecular level).