Evolution Quiz #2

Question 1

What is gene flow (migration)? Give an example.

Answer 1

The movement of alleles as a result of migration. (Example: Grey wolves travel long distances to find mates)

Question 2

What is a habitat/ecological (reproductive) isolation? Is it pre-zygotic or post-zygotic? Provide an example.

Answer 2

Two populations that live in the same environment, but different habitats, ∴ never encounter each other.
- Pre-zygotic
(Example: Garter snakes. Common prefers water; northwest prefers meadows)

Question 3

What is adaptive radiation? Provide an example.

Answer 3

The evolution of an organism into a wide variety of differing types of that same organism.
(Example: Darwin’s finches)

Question 4

What is natural selection?

Answer 4

Organisms that are better adapted to their environment are more likely to survive.

Question 5

What is sympatric speciation?

Answer 5

When a new species forms without a physical barrier.

Question 6

What is a mechanical (reproductive) isolation? Is it pre-zygotic or post-zygotic? Provide an example.

Answer 6

Two closely related species attempt to mate, but are unsuccessful because genitals are incompatible.
- Pre-zygotic
(Example: differing dragonfly species)

Question 7

What is divergent evolution? Provide an example.

Answer 7

A pattern of evolution, where species that were to an ancestral species DIVERGE and become more distinct.
(Example: Wolves and differing breeds of dogs)

Question 8

What is genetic drift?

Answer 8

Changes in an allele frequency because of random events in a population.

Question 9

What is mutation? Give an example.

Answer 9

Any change in the DNA sequence of an organism.
(Example: Rats becoming resistant to poison)

Question 10

What is the founder effect?

Answer 10

New populations that are formed by founders. Founders carry some, but not all, the alleles from the original population.

Question 11

What is a behavioural (reproductive) isolation? Is it pre-zygotic or post-zygotic? Provide an example.

Answer 11

Behaviours involved in mating are so unique that they prevent mating
- Pre-zygotic
(Example: Bird calls)

Question 12

What is hybrid inviability? Is it pre-zygotic or post-zygotic? Provide an example.

Answer 12

Genetic incompatibility stops the development of a zygote.
- Post-zygotic
(Example: if a goat and a sheep mate, an egg will be fertilized, but due to dysfunctional mitosis, the embryo dies)

Question 13

What is gradualism? Is this supported by Darwin or modern research?

Answer 13

Gradualism suggests that evolution occurs at a slow, but constant rate.
- Supported by Darwin

Question 14

What is the bottleneck effect?

Answer 14

When a population is quickly reduced (e.g by a natural disaster) and the surviving population only has a fraction of the alleles that the original population had.

Question 15

What are the requirements for natural selections?

Answer 15

1) Variation in alleles
2) Not all individuals reproduce to their full potential
3) Surviving offspring pass down favourable traits

Question 16

What is the criteria for speciation? (How do you know speciation has occurred?)

Answer 16

Members of a population change so much that they are unable to mate/breed with the original population?

Question 17

What is convergent evolution? Provide an example.

Answer 17

A pattern of evolution where species have INDEPENDENTLY ADAPTED to similar environmental conditions. (Example: Birds, bats, butterflies; all have wings, but do not share a common ancestor)

Question 18

What is a temporal (reproductive) isolation? Is it pre-zygotic or post-zygotic? Provide an example.

Answer 18

Two populations that live in the same environment, but mate at different times. (i.e. of year, of day, of moth)
- Pre-zygotic
(Example: Cicadas mate at different times of year)

Question 19

What is hybrid breakdown? Is it pre-zygotic or post-zygotic?

Answer 19

Offspring are fertile, but become less fertile as generations go on.

Question 20

What is a gametic (reproductive) isolation? Is it pre-zygotic or post-zygotic? Provide an example.

Answer 20

Gametes meet, but do not form a zygote.
- Pre-zygotic
(Example: differing species of sea urchins)

Question 21

What is non-random mating (Inbreeding)? Give an example.

Answer 21

When closely related individuals mate. (Example: Shar-pei dog)

Question 22

What is allopatric speciation?

Answer 22

When a new species forms because of a physical barrier.

Question 23

What does post-zygotic mean?

Answer 23

After fertilization

Question 24

What is punctuated equilibrium? Is this supported by Darwin or modern research?

Answer 24

Punctuated equilibrium suggests that for most of the time species evolve at a constant rate, but are interrupted by periods of divergence.
- Supported by modern research

Question 25

What does pre-zygotic mean?

Answer 25

Before fertilization

Question 26

What is hybrid infertility (sterility)? Is it pre-zygotic or post-zygotic? Provide an example.

Answer 26

Organisms can grow and live a full life, but are infertile.
- Post-zygotic
(Example: Mules are infertile)

Question 27

What is speciation?

Answer 27

The formation of a new species from an existing species.