LO17

Question 1

definition: defines a species as one or more populations whose members can interbreed and produce fertile offspring

Answer 1

biological species concept

Question 2

according to the BSC members of one species are what from members of a different species?

Answer 2

reproductively isolated

Question 3

What are some limitations of the BSC

Answer 3

• cannot be applied to asexual or extinct organisms
• different species occasionally interbreed

Question 4

Why can’t the BSC be applied to asexual or extinct organisms?

Answer 4

Because it is impossible to know about interbreeding in extinct organisms

Question 5

definition: evolution of new species

Answer 5

speciation

Question 6

When does the speciation process begin?

Answer 6

When a population becomes reproductively isolated from other members of its species

Question 7

definition: occurs when interbreeding is prevented between populations

Answer 7

reproductive isolation

Question 8

What happens as a result of reproductive isolation?

Answer 8

The gene pools of the separated populations begin to diverge

Question 9

What would happen when enough genetic differences accumulate?

Answer 9

Gene flow no longer occurs

Question 10

What are the two types of speciation?

Answer 10

allopatric and sympatric

Question 11

Natural selection, mutation, genetic drift, ad gene flow result in what?

Answer 11

microevolution and origin of new species

Question 12

definition: occurs when a population becomes geographically isolated from other populations of its species

Answer 12

allopatric speciation

Question 13

During isolation how does the population get genetic differences?

Answer 13

Due to different selective pressures, genetic drift, reproductively isolated

Question 14

definition:occurs due to some type of geographic barrier or dispersal to a new location

Answer 14

gographic isolation

Question 15

What is required for allopatric speciation to occur?

Answer 15

They need to be geographically isolated

Question 16

definition: occurs when a new species evolves with the same geographic region as its parent species

Answer 16

sympatric speciation

Question 17

definition: can lead to reproductive isolation in a single generation and has likely been the most significant factor in the evolution of flowering plants

Answer 17

allopolyploidy

Question 18

definition: an individual with a nucleus containing more than two copies of each chromosome (>3)

Answer 18

polyploid

Question 19

allopolyploidy occurs when what happens

Answer 19

polyploid arises

Question 20

a common mechanism of sympatric speciation in flowering plants

Answer 20

allopolyploidy

Question 21

Sympatric speciation is what in animals?

Answer 21

rare

Question 21

Sympatric speciation is due to a change is what?

Answer 21

ecology

Question 22

An example of speciation is what?

Answer 22

Lake Victoria

Question 23

definition: prevents interbreeding between closely related species whose geographic ranges overlap

Answer 23

reproductive isolating. mechanisms

Question 24

How do reproductive isolating mechanisms preserves species genetic integrity by what?

Answer 24

preventing gene flow

Question 25

Most species have how many RI mechanisms?

Answer 25

one or two

Question 26

Most RI mechanisms work before what?

Answer 26

before mating

Question 27

definition: reproductive isolating mechanisms that prevent mating and/or fertilization

Answer 27

prezygote barriers

Question 28

definition: reproductive isolating mechanisms that prevent gene flow after fertilization

Answer 28

postzygotic barriers

Question 29

If reproductive barriers are not well developed what would happen?

Answer 29

hybridization

Question 30

Prezygotic barriers prevent fertilization in what ways?

Answer 30

temporal, habitat, behavioral, mechanical, gametic

Question 31

definition: when a closely-related species reproduce at different times of the year

Answer 31

temporal isolation

Question 32

definition: when a closely-related species breed in different habitats in the same geographic area

Answer 32

habitat isolation

Question 33

definition: closely related species use different courtship behaviors

Answer 33

behavioral isolation

Question 34

definition:closely related species have incompatible reproductive organs

Answer 34

mechanical isolation

Question 35

definition: closely related species have gametes that are incompatible due to molecular/chemical differences

Answer 35

gametic isolation

Question 36

postzygotic prevent what from being made as a result of hybridization

Answer 36

viable offspring

Question 37

definition: hybrid embryos die during development

Answer 37

hydbring inviability

Question 38

definition: interspecific hybrids do not reproduce successfully

Answer 38

hybrid sterility

Question 39

definition: the offspring of F1 hybrids cannot reproduce beyond one or a few generation or have reduced fitness

Answer 39

hybrid breakdown

Question 40

What is reason that inviability happens?

Answer 40

Because developmental signals dont interact properly

Question 41

What is a reason that sterility happens?

Answer 41

because different chromosome numbers

Question 42

How do evolutionary novelties rise?

Answer 42

Modification of structures already in existence

Question 43

definition: a structure that a group of organisms already possessed that become modified as it adapt to a new role

Answer 43

preadaptation

Question 44

example of a preadaptation

Answer 44

feathers for flight

Question 45

most preadaptations arise due to what?

Answer 45

mutation in genes that control development

Question 46

What would be the effect of a few mutations in a development gene.

Answer 46

They can have significant phenotypic effect

Question 47

definition: occurs when there is an evolutionary diversification of many species from one or a few ancestral species over a short period of time

Answer 47

adaptive radiation

Question 48

What happens to species diversity during extinction?

Answer 48

They decrease in the short term

Question 49

definition: continuous low-level of extinction that is always occuring

Answer 49

background extintion

Question 50

definition: large numbers of species and higher taxonomic groups are killed off over a period of time

Answer 50

mass extinction

Question 51

Why do mass extinctions happen?

Answer 51

because a major environmental catastrophe

Question 52

examples of adaptive radiation include what?

Answer 52

galapagos finches adapting to different island habitats

Question 53

Allopatric speciation examples include what?

Answer 53

- The isthmus formed separating marine populations - Porto santo rabbits becoming a new species after released on isolated island - Pupfish in Death valley lake split into 20 different species