BIOB50H3 Lecture 1: BIOB50 Lecture 1

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apricotbat126

11 Jun 2016

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Ecology: the scientific study of how organisms affect and are affected by other organisms and their environment. Interactions between organisms & their non-living environments (abiotic) Refers to the fact that events in the natural world can be linked or connected to one another > organism interaction w/ e/o & their physical environment. Does not necessarily mean that organisms have a strong connection w/ e/o, but they are connected to features of their environment (ex. food, space, other resources) Ecologists does not necessarily mean that they are environmental activists. Ecology is a branch of biology, while environmental science is an interdisciplinary field that incorporates concepts from the natural & social sciences (more focused on how people affect the environment & how we can address environmental problems) We can never account for all factors in nature. It can be difficult to predict the outcomes of ecological events and interactions. Levels of organization: organismal ecology, population ecology, community ecology, ecosystem ecology, biosphere.

Related Questions

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

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 Darwinâs 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 âcarrying capacityâ?

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

Question1.1. Accidental alterationsduring DNA replication that give rise to variations in organismsare __________. (Points : 1)

adaptive traits
mutations
symbioses
random distributions

Question2.2. The largest reservoir ofcarbon in the carbon cycle is comprised of _________. (Points :1)

freshwater systems andoceans
plants and animals
sedimentary rock andfossil fuels
atmosphere

Question3.3. The principle of utility________. (Points : 1)

holds that any naturalresource should be available for use in manufacturing
holds that something isright when it produces the greatest benefit for the greatest numberof people
is not an ethicalstandard
cannot be used toestimate the value of natural resources

Question4.4. The two processes thatdetermine current biodiversity on a global scale are __________.(Points : 1)

allopatric speciation andimmigration
mutation and habitatselection
mutation and globalclimate change
extinction andspeciation

Question5.5. The conservation ethicholds that we should ________. (Points : 1)

exploit natural resourcesfor economic gain regardless of sustainability
be prudent and efficientin the use of natural resources
consider the environmentthe ultimate servant of mankind
maintain the environmentin a pristine, unaltered state

Question6.6. The preservation ethicholds that we should ________. (Points : 1)

be responsible for wisemanagement while using natural resources
protect areas againstdevelopment while allowing public access
harvest naturalresources
maintain the naturalenvironment in a pristine, unaltered state

Question7.7. Trophic levels and foodchains diagram __________. (Points : 1)

logistic curves
energy flow in anecosystem
population density
natural resourcefluctuations

Question8.8. A hypothesis is ________.(Points : 1)

a prediction
an educated guess thatexplains a phenomenon or answers a question
an instrument that isused to examine environmental conditions
the design of anexperiment that can be used for the process of science

Question9.9. A biocentric view of theworld emphasizes ________. (Points : 1)

the role of corporationsin environmental law
the importance ofconsidering environmental impacts on all living things
the importance ofeconomics in environmental decisions
the dual-natured view ofhumans and animals as environmental controls

Question10.10. Malthus was responsiblefor ________. (Points : 1)

the book The PopulationBomb that described the disastrous effects of human populationgrowth
the idea that theincrease in human population would lead to famine and war
the concept that humanpopulation growth would lead to greater industry and prosperitythrough education
instituting fertilizeruse for agriculture

Question11.11. Ecology is ________.(Points : 1)

the study of how to solveenvironmental problems
the study of organismsand their interactions with each other and the environment
a subfield ofenvironmentalism
the study of the E. colifamily of bacteria

Question12.12. The scientific processis based on ________. (Points : 1)

observations thatresearchers keep in a scientific journal
testing hypotheses builton observation, and revising them based on results
intuitive understandingof natural laws and processes
the ancient writings ofHeraclitus

Question13.13. Which of the followingis an abiotic factor? (Points : 1)

Amphibians
Wood
Mammals
Water

Question14.14. In environmentalscience, "carrying capacity" means the ___________. (Points :1)

maximum population sizethat a given environment can sustain
average number of viableoffspring produced within a population
potential number ofspecies in a given area
limitation on the numberof species in an ecosystem

Question15.15. The Cuyahoga River madepeople aware of environmental problems because __________. (Points: 1)

people in manycommunities became sick when using water from the river
the drinking water inelementary schools near the river became contaminated
the river caught onfire
the river stoppedsupporting any plant or animal life

Question16.16. The conversion processwhere nitrogen gas combines with hydrogen to form ammonium ions,which is accomplished through the intense energy of lightening orwhen air in the top layer of soil comes into contact with certainbacteria, is known as ________. (Points : 1)

the carbon cycle
nitrogen fixation
ionic conversation
bacterial ionization

Question17.17. The fresh water wedepend on for survival accounts for approximately __________ of allwater on Earth. (Points : 1)

two-thirds
one-third
10%
3%

Question18.18. A paradigm is ________.(Points : 1)

a group of severalhypotheses that can be tested together
a dominant view inscience
the same as ahypothesis
synonymous with thescientific method

Question19.19. The degree of disorderin a substance, system, or process is called ________. (Points :1)

chaos
entropy
energy
electricity

Question20.20. A population is definedas ___________. (Points : 1)

a group of individuals ofmultiple, interacting species that live in a particular area
a group of similarspecies that inhabit various ecosystems
a group of individuals ofa single species inhabiting a particular area
(crude birth rate +immigration rate) - (crude death rate - emigration rate)

periwinklecoyote319

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 âdry ballastâ. 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. âThe 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,â says Einfeldt. âThe idea that so much of what our ecosystem runs on came from our history â it's very exciting.â

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 ânot causing significant harm,â then âaltering oneâs perspective is certainly much less costly than any other sort of management program.â

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 isnât 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.

âSome invasive species are causing problems,â 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 beetleârecently introduced into eastern Canada from Asiaâthat 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 mothsâCanada 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 didnât, natives are better suited to their environment. In fact, says Davis, a scientist who didnât know the history of individual organisms would have difficulty in distinguishing natives from non-natives. The Galapagos Islandsâa world heritage site of biodiversityâprovide 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. âIf you view [nature] as a continually changing tumult, the introduction of new species isnât necessarily looked at as a huge threat.â 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 itâs the oppositeâthe 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 âdegradedâ ecosystem. âThere isnât such a thing as a healthy ecosystem or a sick ecosystem,â Davis says. âEcosystems have no goal or purpose. Theyâre just the species and the physical and chemical processes taking place.â

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, âWe know it caused total global extinction of at least seven species of moths that were host-specific only on North American chestnuts.â

Even if exotics donât drive native species to extinction, they can completely transform ecosystems. âThere are some biotic communities that have entirely disappeared because of invasive species,â says Simberloff. âThere are others that have drastically changed over large areas.â 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. âWe 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.â

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 Areaâs abandoned plantations of Australian eucalyptus trees as a âbiological desert.â Says Sax, âThere 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 werenât always doing the awful things people thought they were doing.â Land managers canât begin to control the thousands of exotics that reach native ecosystems through globalized trade and travel. âConservation biology in the past has been built around the idea of preventing change,â says Sax, âbut itâs impossible to do.â

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 ânovel ecosystems,â never-before-seen agglomerations of species, of which exotics will be a key â and often valued component, Sax and others say. âIf we lump them into this category of all being evil or awful in some way,â he says, âwe may blind ourselves to those situations where theyâre actually providing a benefit either for humans or for biological conservation.â 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, âItâs important to distinguish harm from change.â

BIOB50H3 Lecture 1: BIOB50 Lecture 1

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