Evolution

Question 1

2 types of evolution

Answer 1

• macro-evolution

- micro-evolution

Question 2

Macro-evolution

Answer 2

• deals with the evolutionary relationship among higher species

Question 3

Micro-evolution

Answer 3

deals with the changes in gene frequency

Question 4

Evolution

Answer 4

changes that occur over a period of time

Question 5

Population

Answer 5

all members of a single species occupying a particular area at the same time
•Assumption: each member of a population is assumed to be free to reproduce with any other member. When reproduction occurs, the genes of one generation are passed from parent to offspring

Question 6

Gene pool

Answer 6

all of the alleles in a population

Question 7

Hardy-Weinberg equilibrium formula

Answer 7

a formula used to determine if micro-evolution has occurred.

p2 + 2 pq + q2 = 1

Question 8

Basis of the theory of micro-evolution

Answer 8

The equilibrium of allele frequencies in a gene pool will remain in effect in each succeeding generation of a sexually reproducing population as long as 5 conditions are met.

Question 9

5 Conditions needed to maintain 1:2:1 gene frequency

Answer 9

1. No mutation-the should not be any changes made to the DNA sequences of the population
2. No genetic drift-no chance alteration of gene frequencies
3. No gene flow-no movement of alleles into and out of the population
4. Random mating-members of the population are free to mate with each other and are not restricted to mating with a certain genotype or phenotype
5. No selection-The environment does not favor one phenotype over the other.

Question 10

5 conditions which can change 1:2:1 gene frequency

Answer 10

1. Mutations
2. Genetic drift
3. gene movement
4. Non-random mating
5. Natural Selection

Question 11

Mutations

Answer 11

Alternations in an organism’s DNA

Question 12

Gene flow

Answer 12

The movement of alleles from one population to another

Question 13

Genetic drift

Answer 13

Chance alteration of gene frequencies. (strongly affects small pop)

Question 14

Non random mating

Answer 14

mating based on genotype or phenotype

Question 15

Natural selection

Answer 15

”Survival of the better fit”.

•Some individuals will be more successful than others in

Question 16

Evolution by natural selection requires:

Answer 16

Variation
Inheritance
Differential adaptedness
Differential reproduction

Question 17

Variation

Answer 17

There must be differences or variations seen within the population (the basis for measuring evolution)

Question 18

Inheritance

Answer 18

The differences in the population must be able to be passed from parent to offspring.

Question 19

Differential adaptedness

Answer 19

There must be a factor present which allows one phenotype to adapt and thus survive in the environment as compared to a less viable organism.

Question 20

Differential reproduction

Answer 20

Reproductive process must favor the stronger organisms over the weaker organisms to ensure that the stronger organisms survive.

Question 21

Three types of natural selection

Answer 21

Stabilizing selection
Directional selection
Disruptive selection

Question 22

Stabilizing selection

Answer 22

selects for the heterozygotes and selects against the homozygous dominant or homozygous recessive traits.

Question 23

Directional selection

Answer 23

selects for one or the other extremes. Selects against the heterozygotes as well as the other extreme. Selects for either homozygous dominant or homozygous recessive

Question 24

Disruptive selection

Answer 24

Selects for both of the extremes and selects against the heterozygotes.

Question 25

Speciation

Answer 25

Development of a species

Question 26

Species

Answer 26

a group of interbreeding subpopulation that shares a gene pool and are reproductively isolated from other species.
Reproductive isolating mechanisms

Question 27

2 types of reproductive isolation

Answer 27

Pre-mating isolating mechanisms

Post-mating isolating mechanism

Question 28

4 pre-mating isolation mechanisms

Answer 28

Habitat isolation
Temporal isolation
Behavioral isolation
Mechanical isolation

Question 29

Habitat isolation

Answer 29

organisms may be in same area but in different parts of that area. This is called a habitat

Question 30

Temporal isolation

Answer 30

Their mating time may be different. ( it could be based on the time of day, season or month)

Question 31

Behavioral isolation

Answer 31

they are not attracted to each other. (they may not recognize their pheromones-{a chemical scent}, or their mating call

Question 32

Mechanical isolation

Answer 32

The genitals may not be physically compatible

Question 33

4 Post-mating isolation mechanisms

Answer 33

Gamete isolation
Zygote mortality
Hybrid sterility
F2 fitness

Question 34

Gamete isolation

Answer 34

Even if they are physically compatible, an embryo will not form if the egg and sperm do not properly fuse

Question 35

Zygote mortality

Answer 35

Even if fertilization does occur, the offspring may not survive

Question 36

Hybrid sterility

Answer 36

if the zygote survive, it may not reproduce

Question 37

F2 fitness

Answer 37

If the hybrid is able to reproduce, its offspring may not be able to survive (environment may select against this organism

Question 38

Process of speciation

Answer 38

When reproduction isolation has developed, speciation has occurred.

In addition to reproductive isolation-speciation usually requires geographical isolation.

Question 39

2 types of speciation

Answer 39

Allopatric speciation

Sympatric speciation

Question 40

Allopatric speciation

Answer 40

any speciation that does require the presence of a physical barrier.
•The physical barrier reduces genetic flow.

Question 41

Sympatric speciation

Answer 41

any speciation that does not require the presence of a physical barrier. Here the reproductive isolating mechanism reduces interbreeding and speciation can occur