Chapter 26, Phylogeny

Question 1

Define phylogeny

Answer 1

The (current hypothesis of the) evolutionary history of a species or group of related species

Question 2

Define systematics

Answer 2

The classification of organisms and their evolutionary relationships

Question 3

Define taxonomy

Answer 3

The scientific discipline concerned with classifying and naming organisms

Question 4

Describe the two-part naming system for species

Answer 4

The name is called the binomial, the first part is the genus and the second part, the epithet is unique for each species

The first letter of the genus is capitalized and the entire species name is italicized

Question 5

Name the eight taxonomic groups from broad to narrow

Answer 5

Domain, kingdom, phylum, class, order, family, genus, species

Question 6

What is a taxon?

Answer 6

A taxonomic unit at any level of hierarachy

Question 7

What are the three domains?

Answer 7

Bacteria, Archean, Eukaryota

Question 8

Define phylogenetic tree

Answer 8

The evolutionary history of a group of organisms

Question 9

What do branch points on a phylogenetic tree represent?

Answer 9

The divergence of two species

Question 10

Define sister taxa

Answer 10

Groups that share an immediate common ancestor

Question 11

Define a polytomy

Answer 11

An unresolved pattern of divergence in a phylogenetic tree

Question 12

Define homology and give an example

Answer 12

Similarity due to shared ancestry- bones in whale flippers, bat wings, and human hands

Question 13

Define analogy and give an example

Answer 13

Similarity due to convergent evolution, the Australian marsupial mole and the North American eutherian mole

Question 14

Define cladistics

Answer 14

The grouping of organisms by common ancestry

Question 15

Define clade

Answer 15

A group of species that includes an ancestral species and all its descendants

Question 16

Define a monophyletic clade

Answer 16

Consisting of the ancestor species and all its descendants

Question 17

Define a paraphyletic clade

Answer 17

Consisting of an ancestral species and some, but not all, of the descendants

Question 18

Define a polyphyletic clade

Answer 18

Includes distantly related species but does not include their most recent common ancestor

Question 19

Define shared ancestral character and give some examples

Answer 19

A character that originated in an ancestor of the taxon (distinguishes that clade from sisters)
Ex: milk and hair in mammals, four limbs in birds and mammals

Shared with the species ancestral to more than one group

Question 20

Define shared derived character

Answer 20

A character that is an evolutionary novelty unique to a particular clade

Shared by the ancestral species and a single group
(unique to a clade), mutation in ancestor

Question 21

Define ingroup and outgroup

Answer 21

An outgroup is a species or group of species that is closely related to the ingroup, the various species being studied

The outgroup diverged before the ingroup

Question 22

What is another name for a Basal taxa?

Answer 22

Outgroup