Speciation

Question 1

Define Speciation

Answer 1

The process by which one species splits into 2 or more species

Question 2

4 species concepts

Answer 2

1) Biological Species Concept
2) Morphological Species Concept
3) Ecological Species Concept
4) Phylogenetic Species Concept

Question 3

Define the Biological Species Concept

Answer 3

Species is a group of populations that can interbreed in nature, and produce viable, fertile offspring.

Question 4

Define the Morphological Species Concept

Answer 4

Characterizes species by body shape or other structural features

Question 5

Define the Ecological Species Concept

Answer 5

Characterizes species by how it interacts with the environment
i. Habitat
ii. Diet

Question 6

Define the Phylogenetic Species Concept

Answer 6

Characterizes species as the smallest group that shares a common ancestor
i. One branch on a phylogenetic tree
ii. Comparing molecular gene sequence

Question 7

Define Reproductive Isolation

Answer 7

Barriers that prevent gene flow between groups.

Question 8

Define the two types of Reproductive Isolation

Answer 8

1) Prezygotic Barriers: Before the zygote forms.
2) Postzygotic Barriers: After the zygote forms.

Question 9

What are the 5 Prezygotic Barriers?

Answer 9

1) Habitat Isolation: live in different habitats
2) Temporal Isolation: breed at different times
3) Behavioral Isolation: different courtship rituals
4) Mechanical Isolation: Incompatible reproductive anatomy
5) Gametic Isolation: Gametes cannot unite

Question 10

What is a hybrid?

Answer 10

The offspring from interspecies mating.

Question 11

What are the 3 Postzygotic Barriers?

Answer 11

1) Hybrids Inviability: Hybrid zygote fails to develop
2) Hybrid Infertility: Hybrid is born sterile
i. Chromosomes from parents differ in #
or structure
ii. Meiosis in hybrid can’t produce
functional gametes
3) Hybrid Breakdown
i. First generation hybrids are viable/fertile
(hybrid vigor)
ii. subsequent generations are
feeble/sterile
iii. cultivated crops initially display hybrid
vigor, but then display hybrid breakdown

Question 12

What are the 2 Isolations that prevent gene flow?

Answer 12

Allopatric speciation and Sympatric Speciation.

Question 13

What is Allopatric Speciation?

Answer 13

“Other Homeland”
Speciation that occurs when a population is geographically separates; they live in different areas.

Question 14

What is Sympatric Speciation?

Answer 14

“Same Homeland”
i. Habitat Differentiation: when genetic
factors enable a subpopulation to exploit
a habitat or resource not used by the
other population
ii. Sexual Selection: mate choice as a
reproductive barrier keeping gene pools
separate

Question 15

Define Phylogeny

Answer 15

The evolutionary history of a species or group of species

Question 16

What is Systematics in phylogeny?

Answer 16

The discipline of classifying organisms and determining evolutionary history

Question 17

What is Taxonomy in phylogeny?

Answer 17

The discipline of classifying and naming organisms

Question 18

What is Binomial Nomenclature in phylogeny?

Answer 18

A two-part scientific name
i. created by Carl Linnaeus in the 18th
century
ii. Uses Latin
iii. Genus (species in italics)
iv. Ex: Homo sapiens “wise man”

Question 19

What is Hierarchical Classification?

Answer 19

The grouping of organisms into categories
Domain: Eukaryotes
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primata
Family: Hominidae
Genus: Homo
Species: Sapiens
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Question 20

What is a Phylogenetic Tree?

Answer 20

The Branching Diagram showing evolutionary history

Question 21

What are Cladistics in a phylogenetic tree?

Answer 21

Classifying organisms by inferring phylogeny from homologous character
i. clade: related group
ii. shared ancestral character: character
that originates from the ancestor
iii. shared derived character: novel
character that is unique to a clade

Question 22

What are Branch Points in a phylogenetic tree?

Answer 22

Branch Points show divergence from the common ancestor

Question 23

What are Sister Taxa in a phylogenetic tree?

Answer 23

Sister Taxa are groups that share an immediate common ancestor

Question 24

What does it mean to be Monophyletic in a phylogenetic tree?

Answer 24

“Single tribe”; groups together the ancestor species and all of the descendants

Question 25

What does it mean to be Paraphyletic in a phylogenetic tree?

Answer 25

“Beside the tribe”; groups together the ancestor species and some, but not all of the descendants

Question 26

What does it mean to be Polyphyletic in a phylogenetic tree?

Answer 26

“Many tribes”; groups together many different ancestors

Question 27

What are the 3 ways to determine Phylogeny?

Answer 27

1) Morphology
2) Genes
i. DNA alignment
3) Biochemistry
i. Test function of enzymes

Question 28

What are the 5 types of Morphology?

Answer 28

1) Homology: phenotypic similarities due to shared common ancestry
2) Analogy: convergent evolution producing similar adaptations that evolved separately
3) Plesiomorphy: ancestral homologous trait shared between taxa
4) Apomorphy: derived homologous trait unique to a later clade
5) Homoplasy: analogous trait that evolved separately

Question 29

What is Maximum Parsimony?

Answer 29

It is the simplest explanation that is consistent with the facts
i. Choose the model with the fewest
evolutionary events (mutations)

Question 30

Solve this Maximum Parsimony Problem.
Species 1 CTAT
Species 2 CTTC
Species 3 AGAC
Ancestor AGTT

Answer 30

The hypothesis with only 6 mutations, with 1 and 2 sharing a branch point.

Question 31

What are the Three Domains and Five Kingdoms?

Answer 31

1) Domain Archaea
a. Kingdom Monera - prokaryotes
2) Domain Bacteria
b. Kingdom Monera - prokaryotes
3) Domain Eukarya - Eukaryotes
c. Kingdom Protista
d. Kingdom Fungi
e. Kingdom Plantae
f. Kingdom Animalia