W5 Ch.19 Definitions

Question 1

Phylogeny

Answer 1

The evolutionary history of a group of organisms

Question 2

Phylogenetic Tree

Answer 2

A branching diagram depicting the evolutionary relationships of groups of organisms

Question 3

Node

Answer 3

The point on a stem where one or more leaves are attached

Question 4

Sister Clades

Answer 4

Two evolutionary lineages (ie. clades) that emerge from the same node in a phylogenetic tree

Question 5

Homologous Structures

Answer 5

• similar in anatomical detail and in their relationship to surround structures.

-in multicellular organisms, homologous characters grow from the same embryonic tissues and in similar ways during development.

Question 6

Analogous Structures

Answer 6

Analogous structures are features of different species that are similar in function but not necessarily in structure and which do not derive from a common ancestral feature

Question 7

Synaptomorphies

Answer 7

A derived character state found in two or more species

Question 8

Apomorphies

Answer 8

A derived character state

Question 9

Ancestral Characters

Answer 9

A trait that was present in a distant common ancestor

Question 10

Derived Characters

Answer 10

A new version of a trait found in the most recent common ancestor of a group

Question 11

Clade

Answer 11

A monophyletic group of organisms that share homologous features derived from a common ancestor

Question 12

Molcular Clock

Answer 12

A technique for dating time of divergence of two species or lineages, based on the number of molecular sequence differences between them

Question 13

Lineage

Question 14

Outgroup

Answer 14

A technique used to identify ancestral and derived characters by comparing the group under study with more distantly related species that are not otherwise included in the analysis

Question 15

Cladistics

Answer 15

An approach to systematics that uses shared derived characters to infer the phylogenetic relationships and evolutionary history of groups or organisms

Question 16

Convergent Evolution

Answer 16

The evolution of similar adaptations in distantly related organisms that occupy similar environments

Question 17

Taxonomy

Answer 17

The science of the classification of organisms into an ordered system that indicates natural relationships

Question 18

Systematics

Answer 18

The branch of biology that studies the diversity of life and its evolutionary relationships

Question 19

Anagenesis

Answer 19

Slow lineage, gradual phyletic change

Question 20

Cladogenesis

Answer 20

An ancestral species undergoes speciation producing two descent species, both of which are distant from their common ancestor.

• Increases biodiversity

Question 21

rooted trees are…

Answer 21

• most helpful
• tail
• distinct direction of change and order of splits
• longer branch = longer time to change
• looks at fossil records.

Question 22

Cladogram

Answer 22

Phylogenetic tree that only depicts branching order