Quiz 5

Question 1

Q: What is the Modern Evolutionary Synthesis?

Answer 1

A: A framework combining population genetics with evolutionary biology to explain how traits are inherited and evolve.

Question 2

Q: What are the four requirements of natural selection?

Answer 2

A:

Variability within populations.
Heritability of variation.
Differential survival and reproduction.
Non-random survival and reproduction.

Question 3

Q: Name mechanisms of evolution besides natural selection.

Answer 3

A: Genetic drift, mutation, gene flow, and nonrandom mating.

Question 4

Q: What is a population bottleneck?

Q: What is the founder effect?

Q: Name factors influencing genetic diversity in founding populations.

Answer 4

A: A sharp reduction in population size, leading to a loss of genetic diversity.

A: A reduction in genetic diversity when a new population is established by a small number of individuals.

A:
Source location of propagules.
Propagule size and number.
Post-release conditions

Question 5

Q: How did bottlenecks impact the Common Myna populations?

Q: What did Baker & Mooed (1987) observe about Common Myna?

Answer 5

A: Genetic diversity decreased in non-native populations; the South African population experienced two bottlenecks.
A: Non-native populations had fewer alleles per locus, lower percent polymorphic loci, and lower heterozygosity compared to the native range.

Question 6

Q: What genetic evidence supports multiple introductions of Brown Anole in Florida?

Q: How did rapid evolution manifest in invasive Drosophila subobscura?

Answer 6

A: High genetic diversity in Florida, contrasting with low diversity in native populations.
A: Larger wings evolved in colder climates of the non-native range, adapting to environmental conditions.

Question 7

Q: Why can hybrids become invasive?

Answer 7

A:

Creation of novel genotypes.
Increased genetic variation.
Hybrid vigor (heterosis).
Q: Provide an example of a hybrid becoming invasive.
A: Brazilian Pepper in Florida evolved from hybrids of east and west coast populations.

Question 8

Q: What is character displacement?

Q: How did character displacement manifest in the Small Indian Mongoose?

Answer 8

A: Evolution of greater differences between species where they co-occur compared to where they do not co-occur.

A: Larger sizes evolved in non-native ranges without competitors, compared to native ranges with congeners.

Question 9

qq: What is the founder effect?

Describe the two processes that cause the founder effect.

Answer 9

When an introduced species has a lower genetic diversity than the native population.

• Bottleneck – A low number in individuals introduced (e.g., < 10 unrelated individuals)
• Genetic drift – The random loss of genetic diversity while the population size remains low.

Question 10

qq: U-shaped diversity profiles of introduced species.
a. Describe the processes that create the u-shaped diversity profile of the genetic structure of an invasive
species.

(check chap 11 exercise for curve drawings)

Answer 10

When a non-native species is introduced, the small initial population experiences genetic drift, reducing genetic diversity. Over time, as the population grows rapidly, genetic diversity increases, creating a U-shaped pattern.

Question 11

1- What are some reasons why hybrids may be better invaders than either of the parent species?

b. Hybridization doesn’t always (usually not?) make a species a better invader than the parent species.
Why do you think that may be?

Answer 11

1- * Creates novel genotypes, some of which may be better adapted to the environment than either
parent species.
* Increased genetic variation, which allows the hybrid more adaptability to changing
environments.
* Hybrid vigor – The increase in fitness of hybrids compared to parent types by increasing
heterozygosity (number of heterozygous loci) which masks the expression of deleterious
recessive alleles.

2- * If the parent species are too genetically different, the hybrids will have a lower fitness than the
parent species.
* The novel combination of genotypes may be incompatible, thus, reducing fitness of the hybrids
(either in the specific environment or in general).

Question 12

Why was the genetic diversity of the Myna bird so much lower in South Africa than in the other non-native
locations?

Answer 12

Because the Myna bird in South Africa went through two bottlenecks, first in Mauritius and then in
South Africa.

Question 13

What is an example of a non-native species evolving a genetic structure across a geographic scale that is similar
to the genetic structure in the native range?

Answer 13

The non-native fly, Drosophila subobscura, along the Pacific coast of both North America and South America evolved
variation in wing size similar to that found in its native range of Europe. Specifically, wing sizes were larger in flies at
higher latitudes (i.e., in colder climates both north and south of the equator).

Question 14

What adaptation of the Asian house gecko do researchers hypothesize 1) evolved in urban habitats in its native range and 2) increased its invasibility into non-native urban areas?
Living inside of urban dwellings.
Seeking urban lights to forage on insects.
Toe pads that allow the gecko to grip, and walk up, very smooth surfaces.

Answer 14

Toe pads that allow the gecko to grip, and walk up, very smooth surfaces.

Question 15

How could urban heat islands, where urban habitats are typically warming than adjacent rural habitats, facilitate future invasions of rural habitats?
The higher temperatures in urban habitats reduce the impacts of infectious diseases.
The heat island may provide a suitable habitat for a non-native species establishment, then climate change warms the region, the non-native could invade the surrounding rural habitat.
The higher temperatures in urban habitats reduce the impacts of predators.

Answer 15

The heat island may provide a suitable habitat for a non-native species establishment, then climate change warms the region, the non-native could invade the surrounding rural habitat.

Question 16

How could urban habitats increase the ability for local adaptation of a species?
Lower species diversity in urban habitats allows for more rapid adaptation.
The urban heat islands increase the rate of mutations.
Gene flow is typically low between urban and rural populations, often lower than between two more distant urban populations.

Answer 16

Gene flow is typically low between urban and rural populations, often lower than between two more distant urban populations.

Question 17

The authors in Borden and Flory propose 3 ways that urban evolution could enhance species invasion. What are
those three ways? Discuss and provide examples.

Answer 17

By altering traits that are beneficial under urban condition

By altering traits that could promote the spread and impact of non-native species

By altering traits that provide invaders with a head-start in adapting to future global
conditions.

Question 18

Which of the following results in the greatest competition between native and hybrid species?
Sterile hybrids
Hybrid vigor
No answer text provided.
Introgression

Answer 18

Hybrid vigor

Question 19

How did fire ants impact the field mouse (Peromyscus polionotus)?
The fire ants killed a high proportion of the field mouse population.
The field mouse altered its foraging habitats to feed on the fire ants.
The field mouse changed behavior to occupy habitat that had a high risk of predation to avoid the fire ants.
All answers are correct

Answer 19

The field mouse changed behavior to occupy habitat that had a high risk of predation to avoid the fire ants.

Question 20

How do Pacific rats impact populations of tuataras on islands in New Zealand?
Pacific rats reduce tuatara growth rates by outcompeting them for food resources.
Pacific rats greatly reduce reproduction by killing tuatara eggs and juveniles.
Pacific rats occupy tuatara nesting sites, preventing reproduction.
Pacific rats greatly reduce adult survivorship by killing the adults.

Answer 20

Pacific rats greatly reduce reproduction by killing tuatara eggs and juveniles.

Question 21

How can hybridization with sterile offspring have negative effects on a native species? Give an
example from lecture.

Answer 21

The impacts of sterile hybrids is to reduce the fitness of the native population by ‘wasting’
gametes on sterile hybrids (i.e., the gametes could have been used to produce fertile offspring
with a mate of the same species.

Question 22

What is the primary impact of hybrid vigor on a native population? Give an example from
lecture.

Answer 22

While there is still a waste of gametes the primary effect of hybrid vigor is
that the hybrids have a higher fitness than the native species, thus, over time will tend to
outcompete them and displace the natives.

Question 23

What is the primary impact of introgression on a native population?

Answer 23

The primary impact of introgression is the backcrossing between the native and hybrids causes
invasive genotypes to introgress into the gene pool of the native species. If introgression is
strong enough it could effectively cause ‘genetic extinction’ of the native species.

Question 24

Use the monarch butterfly example to explain how an ‘individual impact’ of a non-native species
causes ‘population impacts’.

Answer 24

The presence of the non-native vine, pale swallowwort, attracts monarchs to lay eggs. However,
the pale swallowwort is a poor host for monarch larvae, resulting in low survival rates. If pale
swallowwort is common, then this can result in a significant decline in fitness of monarchs and a
decline monarch populations as well.

Question 25

How does spotted knapweed outcompete native plants in the northwestern US?

Answer 25

Spotted knapweed uses allelopathy, a chemical that retards the growth of competing species
and allows spotted knapweed to spread.

Question 26

What resource are Mynas and European starlings taking away from native parrots in Australia?

Answer 26

Nest holes.

Question 27

The size distributions of tuataras are larger on islands with Pacific rats. Explain why this is an
indication of the negative effects of the rats on tuatara populations.

Answer 27

The lack of small tuatara’s on islands infested by Pacific rats is due to the rats eating tuatara
eggs and young.

Question 28

How do invasive zebra mussels and golden mussels cause decline of native mussels?

Answer 28

Invasive zebra mussels and golden mussels have a higher growth rate than native mussels,
wherein multiple generations of the invasive mussels attach to native mussels, covering them
with layers of mussels that eventually smothers the native mussels.

Question 29

What was the impact of the rosy wolf snail in the Society Islands?
Caused extinctions of the endemic snails in the genus Partula
Greatly reduced population density of the giant African snail
All answers are correct
Ate the garden plant and crops of island residents

Answer 29

Caused extinctions of the endemic snails in the genus Partula

Question 30

What change in the invasive red fire ants in North America greatly increased their impacts on native communities?
The introduction of phorid flies, a natural enemy to the red fire ant
Development of single queen colonies
Becoming more aggressive to other arthropods than when first introduced
Development of multi-queen colonies

Answer 30

Development of multi-queen colonies

Question 31

What caused the rapid decline in American chestnut in the United States?
Introduction of a transgenically altered variety of chestnut
Introduction of nitrogen-fixing plants
Introduction of a fungal pathogen
Introduction of phorid flies

Answer 31

Introduction of a fungal pathogen

Question 32

give example of

1 A non-native predator that has impacts on a population. And what are the impacts?

2 A non-native predator that has impacts on a community. And what are the impacts?

3 A non-native predator that has impacts on an ecosystem. And what are the impacts?

4 A non-native competitor that has impacts on a population. And what are the impacts?

Answer 32

1 Pacific rats eat the eggs and juveniles of tuatara, extirpating them from New Zealand
Islands.

2 * Nile perch predation on cichlids in Lake Victoria caused extinction of ~200 cichlid
species.
* Rosy wolf snail predation on native snails in the Society Islands caused extirpation of
Partula snails on the islands.
* Sacramento pikeminnow predation caused native fish populations in the Eel River
(California) to move from deep water to shallow water habitats.

3 * Brown trout in New Zealand streams causes increase in primary producers
(phytoplankton) through predation on the consumers of the primary producers.

4 * Spotted knapweed uses allelopathy to retard the growth of competitors, further
endangering the endemic plant Arabis fecunda.
* Bluegill sunfish likely contribute to decline in range and population sizes of the
competitor Sacramento perch, at least partly through aggressive interactions.
* Myna birds and starlings compete with Australian parrots, the crimson rosella and
eastern rosella, for nesting cavities in old trees. The nesting cavities are a limited
resource that has already been reduced due to human activities.
* Zebra mussels and golden mussels reduce access to resources by native mussels by
overgrowing the native mussels, which is causing decline in native mussel populations.

Question 33

give example of:

1- A non-native competitor that has impacts on a community. And what are the impacts?

2- A non-native competitor that has impacts on an ecosystem. And what are the impacts?

3- A non-native herbivore that has impacts on a community. And what are the impacts?

Answer 33

1 The red fire ant in the US has population densities much higher than native ants, is faster at
locating food resources and in higher numbers than natives, and is aggressive toward native
arthopods, significantly reducing species richness and numbers of natives and, more
broadly, native arthropods.

2 Morella faya is a non-native nitrogen-fixing plant that colonizes lava flows in Hawaii. The
lava flows are nitrogen-limited and no native plants are able to fix nitrogen, so colonization
of lava flows was historically a slow process. However, Morella faya is able to rapidly
colonize the lava flows and facilitates invasion by other non-native species by increasing the
available nitrogen.

3 The feral sheep on Santa Cruz Island, California are generalist feeders that prefer endemic
plant species on the island. The impacts of the sheep include reduction in herbaceous cover,
increased bare ground (and thus erosion), the removal of a shrub layer, and elimination of
habitat for ground-nesting birds.

Question 34

What is the primary message of the Sax et al. (2022) paper?
Invasion biologists only focus on the positive effects of non-native species.
Non-native species always have net negative effects.
Invasion biologists only focus on the negative effects of non-native species.
Non-native species usually have a net positive effect.

Answer 34

Invasion biologists only focus on the negative effects of non-native species.

Question 35

What do the authors mean by ‘normative value’?
The value after an invasive species has reached an equilibrium.
No answer text provided.
When positive and negative impacts balance out.
What is considered to be of value based on a value judgement of a population, community, or culture, rather than based on science or a natural law.

Answer 35

What is considered to be of value based on a value judgement of a population, community, or culture, rather than based on science or a natural law.

Question 36

What is the primary point of the Reed et al. response to the Sax et al. paper?
The positive effects of non-native species almost always override any positive effects.
Assessment of the net value of a non-native species should be based on both scientists and non-scientists.
Assessment of the net value of a non-native species should be based on scientific evidence only.
The negative effects of non-native species almost always override any positive effects.

Answer 36

Assessment of the net value of a non-native species should be based on both scientists and non-scientists.

Question 37

Sax et al. separated the values of non-native into three value categories. What are those
categories? Describe them.

Answer 37

Quality of life – Improving people’s quality of life through cultural identity or lifestyle.
Nature’s contribution to people – These can be by directly producing food or resources,
or by indirectly facilitating the production through a variety of ways including
biocontrol, cleaning water, pollinating crop plants…
The intrinsic value of nature – This is described in terms of animal welfare/rights and
increased species diversity due to added non-native species. These will vary a lot among
different people.

Question 38

Honey bees are a non-native species in North America. What benefits do they provide? Which
types of values are these (from Table 1)?

Answer 38

• Honey bees provide two primary benefits to humans. 1) They are used to pollinate crops,
  without which food production in the US would decline greatly. This is a regulatory
  instrumental value. 2) Honey bees produce honey consumed by people. This is a
  provisioning instrumental value.

Question 39

I am a nature lover. I like to go into natural areas, see the native species, and think about the
structure of their food web and how they have evolved in this system. I like knowing that there
are natural areas in the world that haven’t been greatly altered by humans. What type of value
am I placing on a natural system that lack non-native species?

Answer 39

• I think that Sax et al. would classify this as a Quality of life value because I enjoy going into
  nature. However, I also think that my enjoyment is partly due to a feeling of the intrinsic
  value of a natural system that had evolved together over a long period of time with minimal
  human interference. Note: The purpose of this question and answer is not to discount the
  view of Sax et al., but to perhaps provide some explanation for why bias against non-native
  species may arise in some ‘nature lovers’.

Question 40

What was the major point in the Reed et al. response to the Sax et al. paper?

Answer 40

The major point was that the best practice for evaluating the whole of value of non-native
species would require including a diversity contributions from the natural sciences and
outside the natural sciences, and non-scientists alike.

Question 41

qq: The founder effect will be greater when…

low number of individuals are introduced

The introduced individuals are all unrelated

The population growth rate of the introduced population is high

All answers are correct

Question 42

qq: How did geographic variation in the non-native fly Drosophila subobscura mimic geographic variation in the fly’s native range?
a- Populations in colder climates evolved shorter generation times
b- Populations in colder climates evolved larger wings
c- Populations in Los Angeles (but not San Francisco) became cryptic species
d- All answers are correct

Question 43

Which of the following will increase genetic drift in a small population, for example, of a nonnative species?
a. Unequal sex ratios
b. Social mating systems where only a small proportion of individuals reproduce
c. Random factors
d. All answers are correct

Question 44

qq: Which of the following is an example of a non-native predator that caused mass extinction in a native community?
Feral sheep
Brown trout
Rainbow trout
Nile perch

Question 45

qq: Which of the following is an example of a non-native competitor that had an impact on a native ecosystem?
a. Morella faya
b. Spotted knapweed
C. Rosy wolf snail
d. Pacific rat

Question 46

qq: What does a larger size distribution of tuataras on islands shared with Pacific rats tell us about the impacts of the rats on tuatara populations?
a. The rats are killing competitors of tuataras, allowing them to grow larger.
b. The tuataras feed in the rats, allowing them to grow larger.
c. The rats and tuataras form social packs that allow them to more efficiently hunt for prey.
d. The rats are killing the tuatara eggs and young tuataras, which removed all young from the population and prevents reproduction of tuataras.

Question 47

qq: How does hybrid vigor impact the native species?
a. Causes introgression of non-native genes into the native population.
b. Gives the non-native species a competitive advantage.
c. Reduces the competitive ability of a native species.
d. Reduces the competitive advantage of the hybrid.

Question 48

qq: Which of the following statements about the non-native brown anole in Florida is true?
a. The Florida population has a higher genetic diversity than populations on any of the native Caribbean Islands because of multiple introductions to Florida.
b. The Florida population has a low genetic diversity due to the bottleneck effect.
c. The Florida population has a high genetic diversity due to rapid evolution of the nonnative population.
d. The Florida population has a low genetic diversity because it was only introduced into Florida one time.

Question 49

qq: A species of marsh grass is introduced into a non-native region. The non-native marsh grass doesn’t invade, but when it crosses with a native marsh grass, the offspring become highly invasive. What is the name for this phenomenon?
Bottleneck effect
Founder effect
Ecosystem impacts
Hybrid vigor

Question 50

qq: According to Borden & Flory, how could evolution in urban environments enhance species invasion?
a. By altering traits that are beneficial under urban conditions, which could then promote spread into non-native urban areas.
b. By altering traits that could promote spread; for example, the ability to disperse in highly fragmented habitats.
c. By altering traits that provide invaders with a head-start in adapting to future global conditions.
d. All answers are correct