LECTURE 3A_Phylogenetic Systematics, Cladistics

Question 1

are inferred by identifying
organismal features, characters, that
vary among species.

Answer 1

Phylogenies

Question 2

5 organismal features, characters, that
vary among species.

Answer 2

⚫ Morphological
⚫ Chromosomal
⚫ Molecular (genes)
⚫ Biochemistry of living organisms
⚫ Behavioral or ecological

Question 3

evolutionary history or pattern
of descent of a group of organisms.

Answer 3

Phylogeny

Question 4

representation of organisms based on and
describing evolutionary relationships.

Answer 4

Phylogeny

Question 5

Primary goals of systematics

Answer 5

Phylogeny

Question 6

branch of systematics concerned with
inferring phylogeny

Answer 6

Phylogenetic systematics/cladistics

Question 7

Morphological and molecular similarities may
provide clues to

Answer 7

phylogeny

Question 8

Similarities due to shared ancestry are called

Answer 8

homologies

Question 9

Organisms with similar morphologies or DNA
sequences are likely to be ———————– than organisms with different
structures or sequences.

Answer 9

more closely related

Question 10

————— between closely
related species can be small or great.

Answer 10

Morphological divergence

Question 11

may be controlled by
relatively few genetic differences.

Answer 11

Morphological diversity

Question 12

is concerned with grouping individual species into evolutionary categories.

Answer 12

Phylogenetic classification

Question 13

has been made much more
facile by the invention of molecular
taxonomy:

Answer 13

phylogenetic
classfication

Question 14

year of phylogenetic
classfication

Answer 14

early 1980’s (or so)

Question 15

The evolutionary classification of organisms
based on the nucleotide sequence divergence at
individual loci (genes).

Answer 15

molecular taxonomy

Question 16

can really throw a wrench between the two classification philosophies since convergent evolution,

Answer 16

convergent evolution

Question 17

produces phenotypic similarity in the absence of close
evolutionary relatedness.

Answer 17

convergent evolution

Question 18

The trick to solving these discrepancies is to concentrate on ——- and ———

Answer 18

true homologies and ignore convergence.

Question 19

Similarity due to
convergent evolution
is called

Answer 19

analogy

Question 20

it occurs when similar environmental pressures and natural selection produce similar (analogous) adaptations in organisms from different evolutionary lineages.

Answer 20

Convergent evolution

Question 21

When constructing a phylogeny, systematists
need to distinguish whether a similarity is the
result of ——- or ——–

Answer 21

homology or analogy

Question 22

is similarity due to shared ancestry

Answer 22

Homology

Question 23

is similarity due to convergent evolution

Answer 23

Analogy

Question 24

may evolve in such organisms

Answer 24

Similar analogous adaptations

Question 25

Analogies are not due to shared

Answer 25

ancestry

Question 26

A potential misconception in constructing a phylogeny is similarity due to

Answer 26

convergent evolution,

Question 27

A potential misconception in constructing a phylogeny is similarity due to convergent evolution, called

Answer 27

analogy

Question 28

Analogous structures or molecular sequences that evolved independently are also called

Answer 28

homoplasies

Question 29

is critical in the reconstruction of phylogeny.

Answer 29

Distinguishing homology from analogy

Question 30

Homology can be distinguished from

Answer 30

analogy

Question 31

Homology can be distinguished from analogy by comparing ---------------- and ---------------

Answer 31

fossil evidence and the degree of complexity

Question 32

The more complex two similar structures are, the more likely it is that they are

Answer 32

homologous

Question 33

350 million year old animal

Answer 33

first tetrapod

Question 34

had limbs with one long bone (the humerus) attached to two other long bones (the radius and ulna).

Answer 34

the first tetrapod

Question 35

Similar structures inherited from a common ancestor are called

Answer 35

homologous structures or homologies.

Question 36

*Similar structures that evolved independently are called

Answer 36

analogous structures or analogies.

Question 37

Once homologous characters have been identified, they can be used to infer a

Answer 37

phylogeny

Question 38

Shared characters that result from common ancestry are

Answer 38

homologous

Question 39

Independent evolution of similar characters that are NOT homologous is called

Answer 39

homoplasy

Question 40

represents the divergence of two species

Answer 40

branch point

Question 41

are groups that share an immediate common ancestor

Answer 41

Sister taxa

Question 42

includes a branch to represent the last common ancestor of all taxa in the tree

Answer 42

rooted tree

Question 43

diverges early in the history of a group and originates near the common ancestor of the group

Answer 43

basal taxon

Question 44

is a branch from which more than two groups emerge

Answer 44

polytomy

Question 45

Phylogenetic trees show

Answer 45

patterns of descent

Question 46

Phylogenetic trees show patterns of descent, -----

Answer 46

phenotypic similarity

Question 46

do not indicate when species evolved or how much change occurred in a lineage

Answer 46

Phylogenetic trees

Question 47

provides important information about similar characteristics in closely related species

Answer 47

Phylogeny

Question 48

4 applications of phylogeny

Answer 48

⚫ Understanding evolutionary relationships ⚫ Understanding morphological evolution ⚫ Understanding bio-diversification ⚫ Understanding DNA taxonomy of Animals (for species identification)

Question 49

is a method of phylogenetic classification which attempts to limit comparisons within groups only to those characters which are thought to have evolved within a given group

Answer 49

Cladistics

Question 50

comparisons within groups only to those characters which are thought to have evolved within a given group, also known as

Answer 50

derived characters

Question 51

groups organisms by common descent

Answer 51

Cladistics

Question 52

is a group of species that includes an ancestral species and all its descendants

Answer 52

clade

Question 53

Clades can be nested in

Answer 53

larger clades

Question 54

not all groupings of organisms qualify as

Answer 54

clades

Question 55

Cladists consider only

Answer 55

homologous traits

Question 56

traits shared because of a common ancestry.

Answer 56

homologous traits

Question 57

homologous traits supply the most information to a

Answer 57

cladist

Question 58

Phylogenies are often presented as

Answer 58

cladograms

Question 59

Phylogenies are often presented as cladograms with their familiar ---------- and -------

Answer 59

branches and nodes

Question 60

is a graphical representation of a phylogeny.

Answer 60

cladogram

Question 61

cladogram is a graphical representation of a

Answer 61

phylogeny

Question 62

Lines of a cladogram are known as ----- or -------

Answer 62

lineages or clades

Question 63

represents the sequence of ancestral-descendant populations through time, ultimately denoting descent.

Answer 63

Lineages

Question 64

are organisms or species that share derived character states and form a subset within a larger group;

Answer 64

Clades

Question 65

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

Answer 65

Clades

Question 66

A valid clade is -----------

Answer 66

monophyletic

Question 67

signifying that it consists of the ancestor species and all its descendants

Answer 67

monophyletic

Question 68

A group that includes an immediate common ancestral species (known or hypothesized) and all of its descendants

Answer 68

Holophyletic group

Question 69

is a good taxon in an evolutionary sense, meaning that no members which ought to be a part of the taxon

Answer 69

monophyletic taxon

Question 70

in terms of ancestor-descendant relationships, are excluded.

Answer 70

monophyletic taxon

Question 71

is a grouping that consists of an ancestral species and some, but not all, of the descendants.

Answer 71

paraphyletic clade

Question 72

all of whose members are descended from a common ancestor, but which does not include all of the known or considered descendants of that common ancestor.

Answer 72

phylogenetic group

Question 73

is a monophyletic taxon in which a member, other than the most recent common ancestor, is excluded.

Answer 73

paraphyletic taxon

Question 74

represent the improper exclusion of members on the basis of phenotypic differences rather than on the basis of ancestor-descendant relationships.

Answer 74

paraphyletic taxa

Question 75

grouping includes numerous types of organisms that lack a common ancestor.

Answer 75

polyphyletic

Question 76

A grouping that does not include a most recent common ancestor

Answer 76

polyphyletic

Question 77

the most recent common ancestor is assigned to some other group and not to the group itself.

Answer 77

polyphyletic

Question 78

is essentially an erroneously compiled taxonic grouping.

Answer 78

polyphyletic taxon

Question 79

It means that two unrelated taxa have been lumped into one.

Answer 79

polyphyletic taxon

Question 80

polyphyletic taxa can only be done if one includes the common ancestor, but then the resulting taxon would be either ------------ or -----------

Answer 80

monophyletic or paraphyletic

Question 81

2 types of derived characteristics

Answer 81

Apomorphy synapomorphy

Question 82

is an evolutionary novelty unique to a particular clade.

Answer 82

shared derived character

Question 83

is a derived condition

Answer 83

Apomorphy

Question 84

is a derived character shared by the members of the clade;

Answer 84

synapomorphy

Question 85

a derived chracteristic that unites 2 or more lineages

Answer 85

apomorphy

Question 86

evolutionary novelty unique to a particular clade

Answer 86

Shared Derived Characteristics

Question 87

character that originated in an ancestor of the taxon

Answer 87

Shared Primitive/Ancestral:

Question 88

Is a homologous structure that predates the branching of a particular clade from other members of that clade

Answer 88

shared primitive character

Question 89

Is shared beyond the taxon we are trying to define.

Answer 89

shared primitive character

Question 90

2 types Shared Primitive/Ancestral Characteristics

Answer 90

plesiomorphic symplesiomorphy

Question 91

Ancestral character states for a taxon are called

Answer 91

plesiomorphic

Question 92

Sharing these ancestral characters is called

Answer 92

symplesiomorphy

Question 93

do not provide information on nesting of clades – groups with derived characters get left out

Answer 93

Symplesiomorphies

Question 94

A character can be both ------------ and ------------, depending on the context

Answer 94

ancestral and derived

Question 95

one that occurs within a single lineage

Answer 95

Autapomorphy

Question 96

corresponds to a unit of evolutionary common descent.

Answer 96

clade

Question 97

is formed by the derived states of all characters in a study group.

Answer 97

nested hierarchy

Question 98

4 kinds of clades

Answer 98

monophyletic holophyletic paraphyletic polyphyletic

Question 99

more complex two similar structures are, the more likely it is that they are ----------

Answer 99

homologous

Question 100

Similar structures that evolved independently are called

Answer 100

analogous or analogies

Question 101

corresponds to a unit of evolutionary common descent

Answer 101

clade