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BIOL 4245 Study Guide - Midterm Guide: Keystone Species, Primary Production, Cladogenesis

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maroontrout640
1 Apr 2015
School
York University
Department
Biology
Course
BIOL 4245
Professor
Alexander Mills

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Document Summary

All the variety of life on earth. There are 3 levels of biodiversity; genetic, species and ecosystem. It"s a nested scale where all species live in a ecosystem and all genes live in species or live in organisms so it"s nested that sense they are very much connected. Compositional view of species: would be the names like red fox. Structural view of species: would be the forms of species and this would be better for plants and trees. So, the species themselves contribute to the structure of an area of a habitat. Functional view of species: function is a process, Politics: composition would be elected members of parliament, structure would be in the house of commons; the different parties for instance and function would be executing the figure of government. Genetic diversity: there are genetic differences among species, and among populations within species and allelic differences within populations.

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Related Questions

Read the information on exotix and invasive species and answer this question;

writing assignment : Maximum 1 page answer is needed for the below question

Question:Should the government work to prevent the introduction of exotix species to Canada??

From Freeman et al. 2019. Biological Sciences.

Global trade and global travel have vastly increased the rate of exchange of plants, animals, fungi, and microorganisms around the world. A nonnative species that is introduced into a new area is called an exotic species. Exotic species do not necessarily pose problems, and they can even be beneficial in some circumstances. But some exotic species pose a direct threat to native species by eating them, competing with them, causing disease, or other types of interactions. For example, a lethal fungus is spreading from Asia in the exotic salamander pet trade, endangering native salamanders worldwide. Exotic species can also pose indirect threats by changing the local biotic or abiotic resources.

If an exotic species is introduced to a new area, grows to large population size, and disrupts species native to the area, it is called an invasive species. For example, Burmese pythons were set free by pet owners into the Florida Everglades and are now dramatically affecting native wildlife there. Argentine ants have dispersed around the world in food shipments and are forming supercolonies that outcompete native ants. The round goby, a small benthic fish from Eastern Europe first detected in Ontario rivers in 1990, has since spread to all five Great Lakes. The round goby competes for food and spawning habitat with native fishes and is thought to be responsible for the local extinction of native sculpin species from areas of Lake Michigan.

The impact of invasive species can also be beneficial. McMaster University biologist James Quinn and his colleagues investigated the diet of double-crested cormorant chicks in Lake Ontario to determine whether the parent birds were taking advantage of the newly abundant round goby to feed their young. They found that the round goby was the second most frequent fish species eaten by cormorant chicks, suggesting that piscivorous birds are changing their diet to feed on this invasive fish.

Genetic analysis carried out by Tony Einfeldt, a researcher at the University of New Brunswick, suggests that Hediste diversicolor, an abundant polychaete worm in the Bay of Fundy, is an invasive species that originated in France. H. diversicolor is an important prey item for birds and fish in the mud flats in the Bay of Fundy. The polychaete is a poor swimmer with low dispersal ability and could not have made its own way to Canadian waters. The polychaetes live in mud, so they would not end up in ballast water taken in by ships to balance the mass of their cargo. Einfeldt suggests that these species were likely carried to Canada in the early 1600s by ships used by early European explorers such as Samuel de Champlain and Henry Hudson. Prior to 1880, ships lacked ballast tanks, and sailors loaded ships with intertidal material, including rocks, sticks, and mud, as ‘dry ballast’. Hediste diversicolor likely arrived in the Bay of Fundy in this intertidal mud. The worms form burrows and bring water currents through their burrows as they feed. As a result, H. diversicolor acts as an ecosystem engineer, altering nutrient flow and restructuring the muddy intertidal where it lives. The invasive polychaete is also a major food source for millions of birds and fish in the Bay of Fundy and plays a key role in the ecology of the area. “The reason that many of these birds and fish come to our mud flats is to feed on these prey. There are so many of them,” says Einfeldt. “The idea that so much of what our ecosystem runs on came from our history — it's very exciting.”

Modified from Breining. 2009. A New View on Exotic Species. Yale Environment 360

When biologist Mark Davis talks about invasive species, he eventually comes to LTL, his shorthand for Learn to Love them. Invasive species are here to stay, says Davis, so get used to them, and forget about ripping out the fast-spreading plant purple loosestrife on a large scale or throwing Asian carp on the bank to die. If newcomers are only changing the ecosystem but “not causing significant harm,” then “altering one’s perspective is certainly much less costly than any other sort of management program.”

Davis claims that assuming that invasive species are inherently bad, that ecosystem integrity can be measured by the number of alien species, or even that newly arrived species are functionally different from longtime residents, simply isn’t supported by science. Many introduced species have proven valuable and useful, including crops (from apples to wheat), horticultural plants (hostas and Norway maples), and game species (ring-necked pheasants and brown trout). He holds firm to that position, while conceding that some newcomers can be terribly destructive.

“Some invasive species are causing problems,” admits Davis, who says he supports control programs where damage is great and controls stand a chance of success. One highly destructive invasive species causing great economic harm, for which Davis supports eradication programs, is the emerald ash borer, a beetle—recently introduced into eastern Canada from Asia—that typically kills 99% of ash trees in affected areas.

Today, biologists continue to wage a war on alien species that have taken root by accident or design. Zebra mussels, Dutch elm disease, purple loosestrife, Eurasian water milfoil, American bullfrogs, gypsy moths—Canada is beset by exotic species invading native forests, spreading across prairies, and clogging streams and lakes. Davis takes issue with some conventional views of exotic species.

Because native species evolved in a specific ecosystem and exotics didn’t, natives are better suited to their environment. In fact, says Davis, a scientist who didn’t know the history of individual organisms would have difficulty in distinguishing natives from non-natives. The Galapagos Islands—a world heritage site of biodiversity—provide just such an example. For years, conservationists fretted over invasive weeds overrunning the islands. Because the weeds were out of control, conservationists assumed they were non-natives, recently introduced by humans. Research showed, however, that the plants were native and had been present since prehistoric times.

Diverse communities of native species resist invasions by alien species. While carefully controlled experiments on small plots have confirmed this idea, studies in natural forests and grasslands show the opposite, says Davis. Natural disturbances, such as disease or fire, and fluctuations in resources in diverse communities offer plenty of footholds for invaders.

Pristine ecosystems are highly evolved and well-ordered. Again, ecologists have little evidence for this, Davis says. Ragtag assemblages of exotics and natives quickly adapt and perform about as well. “If you view [nature] as a continually changing tumult, the introduction of new species isn’t necessarily looked at as a huge threat.” He cites the example of regeneration of forests in Puerto Rico, where non-native species are facilitating the re-establishment of native species.

The spread of invasive species threatens to drive natives extinct. Rarely happens, Davis says, except on islands, in lakes, or in other insular environments. Usually it’s the opposite—the appearance of exotics increases species richness, he maintains. Throughout Canada, local ecosystems have roughly 20 percent more plant species than they once did because of the addition for foreign species.

Exotics signify a “degraded” ecosystem. “There isn’t such a thing as a healthy ecosystem or a sick ecosystem,” Davis says. “Ecosystems have no goal or purpose. They’re just the species and the physical and chemical processes taking place.”

In some cases, invasions of invasive species do threaten native species with extinction. Chestnut blight, caused by an introduced fungus, swept across southern Ontario in the 1950s and virtually exterminated the native chestnut tree. Ecologist Dan Simberloff says, “We know it caused total global extinction of at least seven species of moths that were host-specific only on North American chestnuts.”

Even if exotics don’t drive native species to extinction, they can completely transform ecosystems. “There are some biotic communities that have entirely disappeared because of invasive species,” says Simberloff. “There are others that have drastically changed over large areas.” For example, Eurasian cheat grass now dominates millions of hectares of Western range, displacing native bunch grasses and reducing the value of the range for livestock.

James Carlton, Pew Fellow in Marine Conservation, contends that biologists can distinguish natives from exotics. “We can easily distinguish natives from many (not all!) non-natives many times in many ways, based very much on how they function in an ecosystem. Native species are often finely tuned physiologically to the environment, whereas nonnative species may possess a repertoire of adaptations that clearly do not match the environment.”

Conservation biologist Dov Sax became positive about the impact of invasive species as an undergraduate at the University of California, Berkeley. A professor leading a field trip described the Bay Area’s abandoned plantations of Australian eucalyptus trees as a ‘biological desert.’ Says Sax, “There was all kinds of stuff growing in there. I found there were really a similar number of species in both [native oak and eucalyptus] woodland types. Exotics weren’t always doing the awful things people thought they were doing.” Land managers can’t begin to control the thousands of exotics that reach native ecosystems through globalized trade and travel. “Conservation biology in the past has been built around the idea of preventing change,” says Sax, “but it’s impossible to do.”

In a matter of decades, researchers believe, animals and plants are adapting to life in a warmer world. Some species will be unable to change quickly enough and will go extinct, but others will evolve, as natural selection enables them to carry on in an altered environment. With global warming pushing some animals and plants to the brink of extinction, conservation biologists are now saying that the only way to save some species may be to move them. The future landscape will be home to “novel ecosystems,” never-before-seen agglomerations of species, of which exotics will be a key — and often valued component, Sax and others say. “If we lump them into this category of all being evil or awful in some way,” he says, “we may blind ourselves to those situations where they’re actually providing a benefit either for humans or for biological conservation.” For example, a recent study of two nonnative wetland plants, suggests they provide waterfowl habitat, biomass production, and nitrogen retention that equals that of native species. Davis feels we should focus instead on disease organisms, agricultural pests, and other threats and says, “It’s important to distinguish harm from change.”

1.

What is a method that some ecologists have proposed to protectspecies from extinction in the face of global climate change?

  1. natural attenuation
  2. assisted migration
  3. bioremediation
  4. mitigation
  5. adaptive management

2.

Why is it usually not possible to restore a community to itspre-altered state?

  1. It is not always possible to determine the kinds of speciesthat populated a community.
  2. Invasive species compromise restoration.
  3. Climate change complicates restoration.
  4. Evolutionary trajectories cannot be predicted.
  5. All answers are correct.

3.

How is ecological restoration different from restorationecology?

  1. It considers cultural and societal concerns.
  2. It does not rely on ecological principles.
  3. It cannot be predicted.
  4. It does not involve manipulation of the environment.
  5. All answers are correct.

4.

What is the goal of assisted migration?

  1. to help species respond to climate change
  2. to help species learn new seasonal migration routes
  3. to help migrating species avoid human-made structures
  4. to help native species tolerate restoration efforts
  5. All answers are correct.

5.

Which of the following might serve to enhance habitat in arestoration project?

  1. a dead log in a stream
  2. a concrete water control structure in an estuary
  3. removal of a dam
  4. an artificial nesting box
  5. All answers are correct.

6.

Biologists want to restore a region that experienced stripmining. How will bacteria assist in the restoration?

  1. They will restore the biotic parts of a community.
  2. They will enhance adaptive management.
  3. They will remove harmful metals.
  4. They will improve revegetation.
  5. They will remove the source of the disturbance.

7.

A barge has leaked a small amount of oil in the middle of LakeMichigan. What might be the best solution to clean it up?

  1. Add molasses to stimulate bacterial action.
  2. Leave it alone.
  3. Introduce engineered bacteria.
  4. Add microorganisms not normally found in the lake.
  5. Launch a comprehensive restoration effort.

8.

Before deciding on an appropriate restoration strategy for aparticular degraded ecosystem, which information would be LEASTimportant to have?

  1. the goals of the restoration, in terms of biodiversity andecosystem functioning
  2. the degree to which the ecosystem has been degraded whencompared to a reference ecosystem
  3. the types of species that were present before thedegradation
  4. the social, political and economic constraints on therestoration
  5. None of the answers are correct.

9.

A biologist works to restore habitat during a restorationproject. Which of the following might serve to enhance thehabitat?

  1. a dead log in a stream
  2. a concrete water control structure in an estuary
  3. removal of a dam
  4. an artificial nesting box
  5. All answers are correct.
  6. 10.
  7. Restoration ecologists want to restore a landscape to itsoriginal state before humans arrived and altered it, but they donot know what species of plants lived there historically. What isthe best alternative?
  8. Import plants from other ecosystems at the same latitude.
  9. Bioremediate the soil.
  10. Use plants growing nearby.
  11. Use assisted migration.
  12. Let nature take its course.

11.

Biologists begin collecting native seeds in a seed bank in aregion that experienced considerable alteration. Describe thebenefits of taking this action for the future.

  1. It is important to collect samples of native seeds for culturalpurposes.
  2. Biologists can use the seeds to restore other regions atsimilar latitudes.
  3. If the region is heavily altered, it may take time and multiplesteps to restore the region. Collecting the seeds while they areavailable ensures that the biologists can use them later in therestoration process.
  4. The see bank will promote the assisted migration of plants fromhabitats made unsuitable by climate change.
  5. All answers are correct.

12.

Although disturbance is often thought of as a detriment tonatural ecosystem functioning, one type of disturbance, fire, isoften used to restore ecological communities. In what way(s) canfire restore ecological communities?

  1. Fire is an effective way to "clean the slate" of the ecosystemby burning plants and sterilizing the soil so that appropriatemitigation and bioremediation plans can be implemented.
  2. In ecosystems where fire is a natural periodic event, fire cankill many non-native plant species while leaving native speciesless influenced.
  3. Fire can suppress the growth of competitive dominant plants,such as shrubs and trees, increasing the diversity of certainecosystems.
  4. All answers are correct.
  5. None of the answers are correct.

As temperatures in an African savanna increase and rainfall decreases, it would most likely change into

tiaga

desert

tropical rainforest

temperate forest

What is imprinting? Give an example.

fixed assocation, such as hatching ducks recognizing the first animal they see as their mother

a learned behavior, such as a wasp circling during a search for food, so that it can return to its nest

alteration of instinct, such as a spider changing the type of web it weaves depending upon the environment

Opportunistic species

provide extensive care for their offspring

produce many offspring

reproduce later in life

What are the five agents of microevolution?

gamete production; mating; fertilization; caring for offspring; formation of herds

photosynthesis; respiration; mitosis; meiosis; fertilization

mutation; gene flow; nonrandom mating; genetic drift; natural selection

Microevolution is

new species

minor extinction of species

changes in allele frequency in a population

Which of the following is does not help defend against predators?

Toxins made by plants that injure caterpillars feeding on the plant

The large eyespots on a moth's wing that can startle a hungry bird

Thorns on a plant

Many plants have brightly colored fruit and flowers

Humans have a favored birth weight, neither too small nor too large. This is

stabilizing selection

disruptive selection

artificial selection

directional selection

What is a keystone species?

the first organism that populates an area

an organism upon which the entire ecosystem depends

the first fossils found in the earliest rock strata

As temperatures in the Arctic warm, which of the following changes may occur?

Tundra will be replaced by taiga

Taiga will be replaced by tundra

Temperate forest will be replaced by taiga

Tundra will be replaced by desert

Taiga will be replaced by temperate rain forest

What is desertification?

restoration of vegetation and water to deserts

areas adjacent to deserts also become deserts

abandonment of a habitat by animals

Evolution occurs at the level of

individuals

populations

communities

The maximum population that the environment can support is called the

biotic potential

environmental resistance

carrying capacity

replacement reproduction

demographic transition

A population with relatively more pre-reproductive individuals is common in _____-developed countries

more

less

Endangered species sometimes breed in captivity. Why are such species endangered in the wild?

Their population density is too high

Loss of habitat

Their environment is polluted

Abiotic components of an ecosystem include

only animal life

only plant life

living components only

nonliving components only

both living and nonliving components

Carbon returns to the atmosphere

as carbon dioxide

from respiration of plants

by the burning of fossil fuels

from respiration of animals

All of the answer choices are correct

Why does the Tropical Rain Forest contain an abundance of antibiotic compounds?

The area is crowded, leading to random production of useful compounds

The area is wet. plants had to develop resistance to fungi and bacterial infections

There is a great diversity of plants, leading to random production of useful compounds

The carrying capacity of the environment for a species is determined by

the reproductive rate of the organism

the number of organisms of that species

the state and national wildlife laws pertaining to that species

a complex

the limited productivity of the environment and the environmental resistance to the biotic potential of the organism

An introduced species that breeds and spreads is

resourceful

harmful

native

dominant

invasive

What is disruptive selection?

environmental influences that select against change

environmental influences that promote one phenotype versus all others

environmental influences that promote two or more phenotypes versus all others

Natural selection acts on

individuals

populations

communities

Two populations of birds live in the same area but have different sleep/wake cycles. This is

behavorial isolation

mechanical isolation

geographical isolation

temporal isolation

An insect that resembles the face of a snake avoids predation by

camouflage

warning coloration

mimicry

chemical defense

mutualism

Unselfish acts that help others in a group so that they increase their chances of surviving and reproducing is called

imprinting

mimicry

altruism

learning

instinct

If an environment changes rapidly, organisms with ____ will be more likely to survive and reproduce.

the correct allele frequency

existing neutral mutations

existing beneficial mutations

How did geology influence Darwin’s thoughts?

It demonstrated that the earth was very old, therefore there was enough time for species to evolve

it demonstrated that all continents were similar

it demonstrated the presence of many fossils

The founder effect occurs when

large groups of individuals leave their home population and establish new settlements, mating only among themselves

many members of a population die, resulting in a great loss of genetic diversity

many members of a population reproduce causing too much genetic diversity within the population

small groups of individuals leave their home population and establish new settlements, mating only among themselves.

The greenhouse effect is due to high atmospheric

Nitrogen

Ammonia

Carbon monoxide

Carbon dioxide

Oxygen

What are the Reproductive Barriers that keep species separate?

lack of food; lack of habitat; lack of potential mates; lack of nesting sites; lack of genetic variation

mountains; canyons; glaciers; bodies of water (for terrestrial animals); areas of land (for aquatic animals)

habitat isolation; temporal isolation; behavioral isolation; mechanical isolation; gamete isolation

What is directional selection?

environmental influences that select against change

environmental influences that promote one phenotype versus all others

environmental influences that promote two or more phenotypes versus all others

Which of the following is correct when describing a predator-prey cycle?

A decline in the numbers of predators causes a decline in the number of prey

A decline in the numbers of prey causes a decline in the number of predators

An increase in the number of predators triggers an increase in the number of prey

An up-and-down cycle will be seen for the prey animal

A seasonal die-off that will occur without the other species present

Why are top-level predators (lions, eagles, humans) so rare in a community?

Only a small amount of the energy is passed from one trophic level to the next

They do not breed as fast as other animals

Because of predation by higher predators

It is difficult for them to learn how to capture prey

Their job is to keep the population size of other animals in check

Alleles conferring bright color to male guppies are common because

they make males less visible to predators

they help males identify each other

they are preferred by females

Organisms that obtain their energy from producers or other consumers are

autotroph

heterotroph

producer

autotroph and producer

heterotroph and producer

What is the environmental impact of strip mining?

lack of trees exposes the surface of the earth, promoting runoff and loss of adjacent trees

removal of minerals from the soil hampers growth of vegetation

it causes a potential increase in volcanic activity

Two populations of squirrels are separated by a mountain range and would not be capable of interbreeding. This is an example of:

behavorial isolation

mechanical isolation

geographical isolation

temporal isolation

What is a danger of overfishing?

humans will become dependent upon fish

selection for smarter fish that can avoid being caught

driving the population back into the lag phase

What is meant by prezygotic versus postzygotic speciation mechanisms?

before versus after formation of a zygote

before versus after meiosis

before versus after gamete formation

The relatively short term changes in allele frequencies within a species or population is

artificial selection

microevolution.

speciation

macroevolution

Avoidance of a location with predators is the result of

imprinting

mimicry

altruism

learning

instinct

What is the difference between Density-Dependent and Density-Independent Factors on populations?

density-dependent factors exert a greater influence when there are more individuals; density-independent exerts the same influence on all individuals regardless of their number

density-dependent factors exert a greater influence on larger, more dense individuals; density-independent factors exert the same impact on individuals of all size

density-dependent factors exert the same influence on all individuals regardless of their number; density-independent factors exert a greater influence when there are more individuals regardless of their number

All of the organisms in a given location or area is termed a

peer group

flock

community

population

herd

The concentration of the pesticide DDT would be highest in

a minnow

a mosquito larva

a seagull

plankton

algae

Our biosphere is

the Earth

the atmosphere

the ocean

land on Earth

fresh and salt water

What is meant by “carrying capacity”?

the amount of food produced in an ecosystem

the extent of energy required to maintain an ecosystem

the number of individuals that can be supported by an ecosystem

Species living on another is

resource partitioning

coevolution

symbiosis

predation

niche sharing

One species feeding on another is

competition

a community

an ecosystem

predation

symbiosis

Populations of different species interacting with one another in a natural environment is called

competition

a community

a biome

predation

symbiosis

Which of the following is not a biogeochemical cycle?

ATP cycle

water cycle

carbon cycle

phosphorus cycle

nitrogen cycle

Horses became larger and faster to escape predators. This is

stabilizing selection

disruptive selection

artificial selection

directional selection