Ch 12 : Diversity of Life

Question 1

Phylogeny

Answer 1

A diagram that shows the evolutionary history and the relationships among a species or a group of species

Question 2

Taxonomy

Answer 2

The science of naming and grouping a species to construct a classification system
- It uses a hierarchical model

Question 3

Linnaean Classification

Answer 3

Consists of a strict hierarchy of taxa
(“Kings play chess on fine green squares”)

1. Kingdom
2. Phylum
3. Class (» Cohort)
4. Order
5. Family (» Tribe)
6. Genus
7. Species (» Subspecies)

Question 4

Nomenclature

Answer 4

Two part naming scheme developed by Linneaus
- Genus + species combined
- Ex.: Homo sapiens, Tyrannosaurus rex

Question 5

Branch Point

Answer 5

The point where a split occurs in a tree which indicates a shared ancestor between two organisms

Question 6

Taxa (singular: taxon)

Answer 6

A single level in the taxonomic classification
system
- The species is given a proper name per level
- Example : Carnivora is the taxon at the order level for Dog

• They are defined by characters which can be morphological, biochemical, genetic, and/or behavioral

Question 7

Rooted Trees

Answer 7

Are trees that have a single taxon at the base of the tree
- All organisms represented in the diagram descend from this taxon

Question 8

Sister Taxa (sister group)

Answer 8

The hypothesized closest relative of a taxon exclusive of their most recent common ancestor

• Consists of two lineages that diverged from the same
  branch point

Question 9

Clade (aka Monophyletic group)

Answer 9

A group that exists in nature as a result of a unique history of descent with modification

• Modification as a result of evolution & adaptation
• Includes all members and the shared ancestor

Question 10

Criteria for Homology

Answer 10

Similarity in structure and anatomical position that indicates shared ancestry

• To be homologous they don’t need to have the same function

Question 11

Analogous Structures

Answer 11

Organisms that contain similar traits (shape, location, possibly function, etc.) but don’t share ancestral origin

• Similar traits are due to adaptive convergence
• Adaptive convergence : two separate lineages of animal converge into the same body shape
  
  • Ex : fish and dolphin

Question 12

Parsimony

Answer 12

Describes a tree that has the fewest number of changes which is considered the simplest and “best”

Question 13

Shared Ancestral Character

Answer 13

A character on a phylogenetic branch that is shared by a particular clade

• It is a characteristic that is found in the ancestor of a group and all of the organisms in the clade

Question 14

Shared Derived Character

Answer 14

A character on a phylogenetic tree that is shared only by a certain clade of organisms but not the whole tree
- The characteristic evolved leading up to that clade