21) Speciation

Question 1

Speciation define

Answer 1

process by which 1 species splits in to 2; the appearance of a new species

Question 2

Species define

Answer 2

kind of organism

Question 3

Define Biological Species Concept

Answer 3

Group of populations whose members have potential to interbreed in nature and produce viable offspring

Question 4

What do same species share

Answer 4

share common gene pool so there is gene flow between populations of same species

Question 5

What occurs because fo lack of gene flow with different species?

Answer 5

reproductive isolation

Question 6

What are the limitations of biological species concept

Answer 6

• Extinct/ fossil species
• asexual species
• virsues/microbes divide rapidly via asexual reproductions

Question 7

What is the biological species concept most ideal for?

Answer 7

extant species

Question 8

Why cant the biological species concept apply to asexual species

Answer 8

because the concept is based on interbreeding

Question 9

Why cant the biological species apply to viruses/ microbes?

Answer 9

asexual, don’t inTerbreed

Question 10

Why doesn’t the biological species apply to extinct/ fossil species?

Answer 10

unable to track them

Question 11

What is the morphological species concept?

Answer 11

Distinguish species by shape/ structure

Question 12

What does the morphological species concept apply equally well to?

Answer 12

sexual, asexual, extinct organisms

Question 13

What is the one limitation of the morphological species concept?

Answer 13

Disagreement over which features and how to divide

Question 14

What is the ecological species concept?

Answer 14

□ Species defined by ecological niche- how individuals interact with living and nonliving parts of environment

Question 15

What does the ecological species concept apply to?

Answer 15

sexual and asexual organisms, but must be extant

Question 16

What is the one limitation for ecological species concpet?

Answer 16

□ Complicated if species can occupy diverse niches

Question 17

Define reproductive isolation

Answer 17

• Mechanisms that prevent members of different species interbreeding and producing viable, fertile offspring

Question 18

What does reproductive isolation prevent?

Answer 18

-gene flow
- prevent formation of hybrids

Question 19

Define hybrids

Answer 19

offspring of 2 different species

Question 20

What is the one flaw of hybrids?

Answer 20

§ Hybrids often low fitness –> selection for mechanisms to prevent hybridization= because they are low fitness they are not really favorable in nature

Question 21

What are the two ways of reproductive isolation

Answer 21

prezygotic barriers and postzygotic barriers

Question 22

List the types of prezygotic barriers:

Answer 22

• Habitat isolation
• Temporal isolation
• Behavioral Isolation
• Gametic Isolation
• mechaniCal isolation

Question 23

Define prezygotic barriers

Answer 23

Operate prior to zygote formation- prevent fertilization

Question 24

Describe habitat isolation

Answer 24

□ Overlapping geographic range, but live/breed in different areas
Rarely interact, no opportunities to mate

Question 25

Describe temporal isolation

Answer 25

□ Overlap spatially but breed at different times of year/season/day So they live in the same habitat but they reproduce at different times so no opportunity to interbreed

Question 26

Describe behavioral isolation

Answer 26

□ Species unique behaviors enable mate recognition □ Must know the right behavior in order to mate

Question 27

Describe mechanical isolation

Answer 27

□ Mating attempted but sexual structures incompatible □ For the other mating can't even be attempt without initial conditions

Question 28

Describe gametic isolation

Answer 28

Molecules or chemical differences between species- egg and sperm

Question 29

What is this an example fo: orchids flower on different days, only open for 1 day for pollination

Answer 29

temporal isolation

Question 30

What is this an example fo: courtship between birds. Birds dance.

Answer 30

behavioral isolation

Question 31

Define postzygotic bArriers

Answer 31

- Operate after fertilization occurs

Question 32

List the three types fo postzygotic barriers

Answer 32

-reduced hybrid viability - reduced hybrid fertility - hybrid breakdon

Question 33

Describe reduce hybrid viability

Answer 33

Embryo nonviable or offspring do not survive (nonviable-unable to survive, grow, or develop)

Question 34

Describe reduced hybrid fertility

Answer 34

□ Hybrid viable, but sterile or low fertility Often due to problems during meiosis

Question 35

Describe hybrid breakdown

Answer 35

□ 1st generation hybrids viable and fertile, □ Hybrids can mate with each other or parent species □Subsequent offspring infertile or frail

Question 36

What is this an example fo: . Mule- female horses (2n=64) + male donkey (2n=62)

Answer 36

reduced hybrid fertility

Question 37

. What is this an example fo: overlapping salamander species sometimes hybridize, rarely develop

Answer 37

reduced hybrid viability

Question 38

How does speciation occur?

Answer 38

Reproductive isolation of populations of same species--> gene pools diverge

Question 39

What are the 2 ways of speciation

Answer 39

allopatric speciation and sympatric migration

Question 40

Describe allopatric speciation

Answer 40

- Geographic Isolation --> drift and/or selection --> divergence

Question 41

What are some mechanisms of separation for allopatric speciation?

Answer 41

□ Geographic barriers- mountain range, river, land bridge, falling water level □ Migration ® Small offshoot population isolated from parent population

Question 42

Describe sympatric migration

Answer 42

- Reproductive isolation without geographic isolation

Question 43

What are the 2 sympatric speciation mechanisms

Answer 43

sexual selection and habitiat differentiation

Question 44

Describe sexual selection

Answer 44

□ Selection for different traits in males and females- traits promote reproductive success, can become barrier to reproduction between subpopulations

Question 45

Describe habitat differentiation

Answer 45

□ Subpopulations use habitat or resource not used by rest of populations □ Can lead to habitat isolation

Question 46

What does habitat isolation lead to

Answer 46

temporal isolation- postzygotic barriers

Question 47

What is the North American apple maggot fly an example of? ® Primarily inhabits the fruits of hawthorn trees but evolved to prefer apples as a new host plant--> reproductive isolation between apply infesting and hawthorn infesting populations

Answer 47

Habitat differentiation

Question 48

What speciation is this an example of and what pre-zygotic barrier? If a population is split and one group starts preferring "blue feathers" while the other prefers "red feathers," they will eventually stop recognizing each other as potential mates. Even if they are physically in the same forest, the "Red" females will simply ignore the "Blue" males because they don't perform the "right" dance or have the "right" look.

Answer 48

Sexual selection & behavioral isolation