Ch 2

Question 1

What are the different Species Concepts?

Answer 1

Morphological SC
Biological SC
Ecological SC
Phylogenetic SC

Question 2

What is the morphological SC based on?

Answer 2

visual similarities

Question 3

What is the biological SC based on?

Answer 3

based on reproduction / gene flow within a population

Question 4

According to the biological SC, members of a different species do not interbreed because of pre-zygotic and post-zygotic “blocks.
What are the pre-zygotic blocks?

Answer 4

Mechanical Isolation
Behavioral Isolation
Temporal
Ecological Isolation
Gametic Isolation

Question 5

What is mechanical isolation?

Answer 5

populations are structurally unable to reproduce

Question 6

What is behavior isolation?

Answer 6

individuals don’t recognize mating rituals from other poulations

Question 7

What is temporal isolation?

Answer 7

individuals have different mating times (day, year, age)

Question 8

What is ecological isolation?

Answer 8

individuals have different mating locations

Question 9

What is gametic isolation?

Answer 9

different chemical signals of gametes (do not fuse; are syngamy)

Question 10

According to the biological SC, members of a different species do not interbreed because of pre-zygotic and post-zygotic “blocks.”
What are the post-zygotic blocks?

Answer 10

hybrid inviability

hybrid sterility

Question 11

What is hybrid inviability?

Answer 11

zygote does not develop (death before development)

Question 12

What is hybrid sterility?

Answer 12

hybrids are sterile

no gene flow between populations

Question 13

What is the ecological SC?

Answer 13

otherwise similar organisms/groups may be distinguished by niche preference within a variable environment

Question 14

What is the phylogenetic SC?

Answer 14

populations can be traced to a common ancestor that has evolved significantly different differences in diagnostic traits

Question 15

How do new species form?

Answer 15

Speciation

Question 16

What does speciation involve?

Answer 16

• reproduction isolation of 2 or more populations of an ancestral species
• genetic divergence of the isolated populations

Question 17

What are the different types of speciation?

Answer 17

Allopatric speciation

sympatric speciation

Question 18

What is allopatric speciation?

Answer 18

when formerly isolated population re-converges with and is no longer able to reproduce with ancestral population

Question 19

Steps to allopatric speciation

Answer 19

• geographic isolation of 2+ populations from an ancestral species
• genetic divergence (mutations)
• reproductive isolating mechanism is evolved
• new species

Question 20

What is Sympatrick Speciation?

Answer 20

A mutation occurs within the ancestral population

Question 21

Steps to Sympatric Speciation

Answer 21

Ancestral population

• isolated mechanism is formed within population
• genetic divergence occurs
• new species

Question 22

What are 2 changes that support Sympatric Speciation?

Answer 22

Ploidy Changes

Changes in Ecological Factors

Question 23

What are Ploidy Changes

Answer 23

Part of Sympatric Speciation

- polyploidy: 3+ complete sets of chromosomes

Question 24

What types of Ploidy Changes are there?

Answer 24

Autopolyploidy

Allopolyploidy

Question 25

What is Autopolyploidy?

Answer 25

Polyploid is formed by non disjunction during meiosis

Question 26

Is autopolyploidy more common or less common to allopolyploidy?

Answer 26

Less common

Question 27

What is Allopolyploidy?

Answer 27

Closely related but differing species produce hybrid - hybrid doubles the # of chromosomes through non disjunction - results in allopolyploidy - generic divergence occurs - new species

Question 28

What are Changes in ecological speciation?

Answer 28

Part of Sympatric Speciation - simple mutation producing a change in niche preference / mating behavior - this disrupts selection

Question 29

What is adaptive radiation?

Answer 29

When 1 species grows into many more

Question 30

What is character displacement?

Answer 30

When 2 similar, isolated species come together They will have to compete not only within species, but with the new species as well This causes each species average characteristics to move toward the extremes

Question 31

What happens at the hybrid zone between closely related species?

Answer 31

Fusion Reinforcement Stability

Question 32

What is fusion in the hybrid zone?

Answer 32

Gene flow occurs into both populations | -this merges the gene pools

Question 33

What happens during reinforcement in the hybrid zones?

Answer 33

Hybrids are less successful in producing offspring | -this strengthens reproductive isolating factors over time

Question 34

What is stability in the hybrid zones?

Answer 34

Hybrids are formed | -no significant fusion or reinforcement occurs

Question 35

What is Phyletic Gradualism?

Answer 35

Steady change within a lineage | -older theory

Question 36

What is Punctuated Equilibrium?

Answer 36

``` Rapid Speciation (a Speciation event) -followed by stability (stasis) ```

Question 37

When was the earth formed?

Answer 37

4.5b yrs ago

Question 38

When were the oldest fossils found

Answer 38

3.5b yrs ago

Question 39

When did the banded iron formations occur?

Answer 39

2.2-2.8b yrs ago

Question 40

What was the significance of the banded iron formations?

Answer 40

Pointed to massive amounts of free oxygen in the air - likely causes by photosynthesis - resulted in iron being oxidized and precipitating

Question 41

When was the oldest eukaryotes fossils dated to?

Answer 41

2.1b yrs ago

Question 42

When we’re the oldest tetrads dated to?

Answer 42

1.1b yrs ago

Question 43

What’s the significance of tetrads?

Answer 43

Sexual reproduction

Question 44

What’s the earliest multicellular animal fossil?

Answer 44

600m yrs ago

Question 45

When’s the earliest plant?

Answer 45

425m yrs ago

Question 46

When is the modern homo sapien dated?

Answer 46

30-50k yrs ago