CH 20 Phylogeny

Question 1

Who is the founder of modern taxonomy?

Answer 1

Carolus Linnaeus

Question 2

What is Binomial Nomenclature?

Answer 2

2-part scientific name (being the genus and then the specific epithet)

Question 3

What is the 1st Part of a binomial nomenclature name?

Answer 3

The Genus

Question 4

What is the 2nd part of a binomial nomenclature name?

Answer 4

The specific epithet that distinguishes species within a genus

Question 5

What are the 3 main rules for writing binomial nomenclature names?

Answer 5

-The 1st letter of the genus (1st part of the name) must be capitalized
-The 2nd part of the name can NOT have any capital letters
-The whole name MUST be written in italics, if handwritten underline it instead

Question 6

What are the Taxonomic Classification Levels? From Greatest (most broad) to least (most specific)

Answer 6

Greatest (Most Broad) –> Least (Most Specific)
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 7

What is a phylogenetic tree?

Answer 7

the evolutionary history of a species or group of related species

Question 8

Who was the first to depict the relationship of organisms in a tree-like diagram?

Answer 8

Darwin

Question 9

Phylogenetic Trees are hypotheses about ____?

Answer 9

Evolutionary Relationships

Question 10

What are systematics?

Answer 10

a discipline that classifies organisms & determines their evolutionary relationships

Question 11

What is a taxon?

Answer 11

a taxonomic unit at any level of hierarchy

Question 12

What is a Branch Point (or Node) ?

Answer 12

a divergence of two taxa from a common ancestor, in short it represents a common ancestor

Question 13

Sister Taxa are

Answer 13

Closest Ancestors

Question 14

A rooted tree has a ?

Answer 14

branch representing the most recent common ancestor of all taxa in the tree

Question 15

What is a Basal Taxon?

Answer 15

early division in a history of group
-also called the OUTGROUP

Question 16

What is a Polytomy?

Answer 16

a branch that has 3 or more groups emerged
- this is because we don’t know which 2/3 are more closely related resulting in the polytomy

Question 17

Rooted Phylogenetic tree’s Generally do NOT show what?

Answer 17

*when a divergence occurs
-unlesss, theres a molecular clock at
*how much change occurs in a lineage
-unrooted phylogenetic trees DO
show genetic change through the
length variations in each root

Question 18

Phylogenies are based on?

Answer 18

homologies

Question 19

When inferring phylogenies the similarities MUST result from?

Answer 19

Shared ancestry (must homologous, NOT analogous)

Question 19

What is a homology?

Answer 19

similarities in structure, physiology, or development shared between different species of organisms that share a common ancestor

Question 20

What is a analogy?

Answer 20

similarities in analogy evolved independently due to convergent evolution, aka from similar habitat/selective pressures
-does not provide information on ancestry!

Question 21

Phylogenies are inferred from what kind of similarities?

Answer 21

Homologous - phenotypic and genetic similarities from SHARED ANCESTRY!!

Question 22

Define Cladistic

Answer 22

classifies organisms by common descent

Question 23

Define Clade

Answer 23

a group of species that includes an ancestral species AND all of its descendants
clades can be nested in larger clades, but not all groupings of organisms qualify as clades

Question 24

A valid clade must be ?

Answer 24

Monophyletic
-a group of organisms that consists of all known descendants of the groups ancestor (often the ancestor itself is included)