SPECIATION

Question 1

who said “species are groups of interbreeding natural populations that are reproductively isolated from other such groups”

Answer 1

Ernst Mayr (1969)

Question 2

here, There is gene flow

Answer 2

species

Question 3

ØThe process by which new species arise.

Answer 3

species

Question 4

who said that species is the process by which new species arise.

Answer 4

(Kardong 2005)

Question 5

who said the origin of discontinuities between populations caused by the development of reproductive isolating mechanisms

Answer 5

(Mayr 1969, Glossary).

Question 6

The origin of discontinuities between populations caused by the development of

Answer 6

reproductive isolating mechanisms

Question 7

“every population of a species differs from all others,” and “the degree of difference between populations of a species ranges from almost complete identity to distinctness almost of species level.”

Answer 7

Speciation

Question 8

here, Gene flow between population is interrupted

Answer 8

Speciation

Question 9

2 Reproductive isolating mechanisms

Answer 9

1. Prezygomatic isolating mechanism
2. Postzygomatic isolating mechanism

Question 10

Prevents
reproduction
between
individuals of
different species

Answer 10

Reproductive isolating mechanisms

Question 11

4 steps to speciation

Answer 11

1. Single population
2. Barrier development
3. Differentiation
4. Barrier Disappearance

Question 12

The ancestral species is a single reproductive
community – a single species.

Answer 12

Single population

Question 13

here All members can interbreed

Answer 13

Single population

Question 14

here they are genetically isolated from other species.

Answer 14

Single population

Question 15

here a Physical barrier such as mountain range or wide body of water, or occupying different regions in a forest canopy

Answer 15

Barrier development

Question 16

At this point, the population is simply divided giving rise to allopatric populations (ranges do not overlap);

Answer 16

Barrier development

Question 17

At this point, the population is simply divided giving
rise to

Answer 17

allopatric populations

Question 18

here Gene flow between population is interrupted but still can interbreed if brought together;

Answer 18

Barrier development

Question 19

Variation arising within one population is not shared
with the other via

Answer 19

interbreeding

Question 20

here, Variation arising within one population is not shared with the other via interbreeding;

Answer 20

Barrier development

Question 21

Each divided population experiences different environmental
conditions and having different selective pressures;

Answer 21

Differentiation

Question 22

here, Each population adapt to the local conditions, favoring adaptive
traits, and accumulating it through successive generations.

Answer 22

Differentiation

Question 23

here, Each population undergoes independent evolution and becomes
genetically distinct (genetic drift).

Answer 23

Differentiation

Question 24

here, (divergence) has occurred

Answer 24

Differentiation

Question 25

it is when The two divided population come into contact

Answer 25

Barrier disappearance

Question 26

it is Overlapping geographic distribution

Answer 26

Barrier disappearance

Question 27

Due to divergence, they are now genetically incompatible unable to produce viable offsprings (reproductive isolation)

Answer 27

Barrier disappearance

Question 28

Due to divergence, they are now genetically incompatible unable to produce

Answer 28

viable offsprings

Question 29

Due to divergence, they are now genetically incompatible unable to produce viable offsprings

Answer 29

(reproductive isolation)

Question 30

it is Where there was once single species, now there are two

Answer 30

(speciation)

Question 31

when they could re-unite to form single species again

Answer 31

(no speciation)

Question 32

2 situations that occur --------- Where there was once single species, now there are two (speciation) OR they could re-unite to form single species again (no speciation)

Answer 32

Barrier disappearance

Question 33

3 modes of speciation

Answer 33

1. Allopatric Speciatio 2. Parapatric Speciation 3. Sympatric Speciation

Question 34

“Speciation that arises due to geographic isolation from its ancestor.

Answer 34

ALLOPATRIC SPECIATION

Question 35

(barriers) new mountain range, new river formation cutting through continuous population, or habitat fragmentation

Answer 35

ALLOPATRIC SPECIATION

Question 36

2 models for allopatric speciation

Answer 36

1. “Dumb-bell” model (Mayr) 2. Peripheral isolate model

Question 37

(Peripatric Speciation)

Answer 37

Peripheral isolate model

Question 38

model in which the ancestral species is divided into two roughly equal halves, each of which forms a new species

Answer 38

Dumb-bell model

Question 39

in which the new species forms from a population isolated at the edge of the ancestral species range

Answer 39

peripheral isolate model

Question 40

Peripheral isolate model

Answer 40

Peripatric Speciation

Question 41

Small population, at the extreme edge of the species’ range, becomes separated from the main group

Answer 41

Peripatric Speciation

Question 42

speciation observed on islands

Answer 42

Peripatric Speciation

Question 43

Occurred much more commonly in evolution

Answer 43

Peripatric Speciation

Question 44

More probable that a small population would be isolated at the edge of a species range than dividing the whole of a species range

Answer 44

Peripatric Speciation

Question 45

it is when Isolated population at the edge of a species range frequently show distinct forms, compared to individuals in the main part of the species range which show less variation.

Answer 45

Peripatric Speciation

Question 46

The process by which selection increases reproductive isolation, independently of the history of the populations.

Answer 46

Reinforcement

Question 47

It is called secondary if the reproductive isolation has partly evolved allopatrically, and is then reinforced when the two populations come into secondary contact.

Answer 47

Secondary reinforcement

Question 48

It is called --------- if the reproductive isolation has partly evolved allopatrically,

Answer 48

secondary

Question 49

it is called ------- when the two populations come into secondary contact.

Answer 49

reinforced

Question 50

When the diverged populations meet again, reproductive isolation may be reinforced by

Answer 50

natural selection

Question 51

When the diverged populations meet again, reproductive isolation may be reinforced by natural selection. speciation might then be speeded up by selection in

Answer 51

sympatry

Question 52

hybrids are formed which are of lower fitness than either parental form, selection would

Answer 52

act to increase the reproductive isolation

Question 53

New species evolve from ----- --------, rather than completely separate ones (as in allopatric speciation).

Answer 53

contiguous populations

Question 54

is an area of contact between two noticeably different forms, or races, of a species at which hybridization takes place

Answer 54

Hybrid zone

Question 55

exists because of the dispersal of individuals out of the area to which they are best adapted.

Answer 55

Hybrid zones

Question 56

Hybrid zones exists because of the dispersal of individuals out of the area to which they are best

Answer 56

adapted

Question 57

No barrier to gene flow

Answer 57

Parapatric Speciation

Question 58

2 Stages for Parapatric speciation

Answer 58

1. Divergence along an environmental gradient 2. Reinforcement

Question 59

if there is selection against hybrids (meaning hybrids are disadvantageous)

Answer 59

Natural selection favoring reproductive isolation

Question 60

Natural selection favoring reproductive isolation if there is selection against hybrids (meaning

Answer 60

hybrids are disadvantageous

Question 61

Natural selection favoring reproductive isolation if there is selection against hybrids (meaning hybrids are disadvantageous)

Answer 61

Reinforcement

Question 62

Two different forms are then selected to mate only with others of their own type.

Answer 62

Reinforcement

Question 63

Hybrid zones are example of stepped

Answer 63

clines

Question 64

a geographic gradient in a character within a species

Answer 64

Cline

Question 65

are a kind of geographic variation, and they will evolve when different genotypes are favored in different places.

Answer 65

clines

Question 66

it is when A species splits into two without any separation of the ancestral species’ geographic range.

Answer 66

Sympatric speciation

Question 67

A species splits into two without any separation of the

Answer 67

ancestral species’ geographic range

Question 68

here, We need a stable polymorphism in which assortative mating would be favored by selection.

Answer 68

sympatric speciation

Question 69

We need a stable ------- in which assortative mating would be favored by selection.

Answer 69

polymorphism

Question 70

Condition in which a population possesses more than one allele at a locus.

Answer 70

Polymorphism

Question 71

The condition of having more than one allele with a frequency of over 5% in the population.

Answer 71

Polymorphism

Question 72

Tendency of like to mate with like

Answer 72

Assortative mating

Question 73

Genotype AA with AA

Answer 73

Assortative mating

Question 74

Phenotye – tall individuals with tall individuals

Answer 74

Assortative mating

Question 75

it will result in a distribution of beak sizes that matches the resource distribution

Answer 75

random mating among bird genotypes

Question 76

2 characters used in seger's model

Answer 76

- seed sizes have a normal distribution - seed sizes have a flat distribution

Question 77

Have not found hybrid coloration suggest that the two and separate “good” species that do not interbreed naturally is an example of

Answer 77

sympatric speciation

Question 78

3 examples of Genetic experiments:

Answer 78

C. carnea color phenotype C. downesi color phenotype Intermediate in color

Question 79

homozygous dominant (G1G1)

Answer 79

C. carnea color phenotype

Question 80

homozygous recessive (G2G2)

Answer 80

C. downesi color phenotype

Question 81

heterozygote (G1G2)

Answer 81

Intermediate in color