Lecture 18-20

Question 1

When did food productions begin in human civilization?

Answer 1

Food production = deliberate raising of animals and cultivation of cereal grasses and edible root plants

12 000 years ago

Question 2

What is domestication?

Answer 2

A change in the gene pool of a plant or animal resulting from a coevolutionary process

Example: wolves –> dogs

Question 3

How can domestication occur?

Answer 3

Through artificial selection: humans manipulate plant/animal breeding to selectively develop particular phenotypic traits by choosing which males and females will reproduce or allowing reproduction/survival to occur in a controlled envr

Question 4

What kind of traits are being selected in modern days to survive farm conditions?

Answer 4

Ability to survive stress (de-beaking, crowded conditions, caging)

High production (egg, meat, milk)

Ability to survive food (e.g. cows fed corn –> not their natural diet)

Can select for disease resistance but also increased reliance on anti-parasitics, antibiotics, etc. to control disease caused by conditions

Question 5

Which traits are selected for today in plants?

Answer 5

Resistance to herbicides
Production of non-viable seed (so farmers dependent on yearly seed purchases)
Uniform germination and maturation times (so they can all be harvested at once)
Unifrom grain size
Disease and pest resistance
High yield
Herbicide tolerance
Food quality (protein content, flavour, etc.)
Storage quality

Question 6

What is the result to modern day selection in plants?

Answer 6

Only the highest yield plants and animals persist to retain financial solvency

Many plant species are genetically identical

Only the highest yield species persist

Question 7

How are modern crops experiencing genetic bottleneck?

Answer 7

Crop plants are often extensively inbred and not allowed to reproduce sexually in the field, severly limiting their gene pool and reducing variation needed to adapt (e.g. to climate change)

Question 8

What percentage of canola growth in Canada is GMO?

Answer 8

95%

Question 9

How many GMO food crops are sold in Canada?

Answer 9

9

Question 10

What are GMO?

Answer 10

Genetically modified organism

Creates combination of plant, animal, bacteria and virus genes that do not occur in nature or through traditional crossbreeding methods

Traits added: herbicide resistance (weed control), pest resistance, reduced browning

Question 11

Are GMOs a short-circuit of evolution?

Answer 11

Actually, genges move between kingdoms in nature quite regularly

But there is potential for hybridization

Question 12

What is the result of rapid evolution of antibiotics?

Answer 12

Antibiotic use is widespread in agriculture for increasing yield and enabling high density

This results in rapid resistance, significant concerns about loss of effectiveness and spread

Superbugs can arise, resistance to pesticides

Question 13

What are some specific ways that agriculture has changed the planet?

Answer 13

Ecosystem displacement/fragmentation

Source of CO2, NOx and CH4

Shifts in animal biomass (livestock now vastly outweigh all wild mammals)

Eutrophication (nutrient enrichment)

Pesticide bioaccumulation

Erosion

Freshwater depletion

Salinization

–> all of these changes modify the selection pressures, gene flow and genetic diversity of populations

Question 14

What are the impacts of ecosystem displacement/fragmentation?

Answer 14

37% of earth is now used for agriculture of some kind (the only two large areas that aren’t are the world’s two largest rainforests that are under significant threat)

Removal of entire tracts of ecosystem

Agriculture land use is a huge driver of deforestation (causes drought, fire, disease)

Question 15

What are the impacts of agriculture of GHG emissions?

Answer 15

Come from enteric fermentation (livestock), manure, fertilizer, rice paddies

Agriculture management (tillage, grazing) also cuases loss of stored C in soils

Clearing peatland/wetlands also increase CO2 emissions a lot

Question 16

What is the impact of agriculture on eutrophication?

Answer 16

A lot of fertilizer runoff from agriculture (contains N and P runoff)

Goes into air or water

Excess nurients causes algal blooms, growth of parasites, kills fish

Human health issues

Question 17

What are the impacts of pesticides?

Answer 17

Many pesticides do not break down, and are magnified up the food chain (bioaccumulation)

Many non-target effects (DDT on bird eggs, fish kills)

Question 18

What is the impact of erosion?

Answer 18

Heavy grazing, ploughing break up soil aggregates and remove stabilizing vegetation

Result can be massive loss of topsoil

Depletes soil carbon stocks

Question 19

How is freshwater impacted by agriculture?

Answer 19

Agriculture is majorly reshaping hydrology via dams and aquifer depletion

Water likely to be a major dirver of international conflict in the decades to come

Ex. the colorado river –> now rarely reaches the sea, every last drop of its water fully overallocated, no delta habitat (pop. of fish, shrimp, and sea mammals have seen dramatic decline)

Question 20

What are the impacts of salinization?

Answer 20

Uplift of water from deep basins has brought subsurface salts to the surface

Land now very inhospitable since high salt content prevents vegetation growth

Question 21

How has agriculture changed human society?

Answer 21

Allowed permanent settlements: affected almost all aspects of society and the economy

Greater amounts of food, more reliable

Storage: delayed-return rather than immediate return

Support of non-producers
- specialization and division of labour

Sedentism (staying in one place)

Great pop. density

–> this all lead to disease, land ownership, land degradation

Question 22

How has agriculture changed our bodies?

Answer 22

The advent of agriculture lead to a decline in general and oral health due to an increase in carbohydrates, softer calorie-dense foods, reduced diet variety
- This lead to reduced skeletal robustness, shorter stature, smaller jaw, dental decay and malocclusion

Small mobile populations gave way to large settlements, with close proximity of humans and animals. Sanitation was poor
- Zoonotic diseases: influenza, smallpox, measles, tuberculosis
- Communicable diseases: the above, plus things like cholera

Evidence for changes in areas of the genome associated with immunity, lactose tolerance, digestion, pigmentation

Question 23

What are some ways to improve agriculture going forward?

Answer 23

Preserving the gene pool

Agroecology

Question 24

What are the main 5 global drivers of change?

Answer 24

Climate change
Habitat loss
Overexploitation
Pollution
Invasive species

Question 25

What are invasive species?

Answer 25

A non-indigenous species whose introduction does or is likely to cause economic or environmental harm or harm to human health Causes damages by changing biotic interactions

Question 26

What is the societal relevance of invasive species?

Answer 26

Major cause of biodiversity loss, physical changes, industrial impacts (economic cost), aesthetics (defoliated forest), property values

Question 27

What are the 5 processes of a species invasion?

Answer 27

Source location of species Transport/introduction Establishment Spread Impact

Question 28

What are some examples of pathways of invasion?

Answer 28

On purpose: commerce in living organisms, aesthetics, food, livestock, pets, biological control, etc. Transport related: shipping cargo, travelers in baggage, in wood, on planes/boats, ballast water, canals, etc. The more number

Question 29

What are some common traits of invasive species?

Answer 29

Generalists (eating a lot of thigns), high tolerance for different environmental conditions, phenotype variations

Question 30

What are common traits of invaded ecosystems?

Answer 30

Islands/lakes --> relationship between diversity and size Smaller areas

Question 31

How were zebra mussels introduced? What are their impacts?

Answer 31

Introduced through ballast water discharge They invade pipes, and suffocate other mussels/organisms

Question 32

How do invasive grasses promote a positive feedback loop?

Answer 32

Introduction of highly flammable plants increase wildire risk --> more fires --> envr becomes more dry --> drier environments are more prone to fires --> promotes the growth of invasive species

Question 33

What are general policies/management options for each process of an invasion?

Answer 33

Species in pathway: prevention -- > reduce species in pathways, institute risk screening Transport: early detection, rapid response --> monitor for early invasions Establishment: eradication --> provide authority and funding for eradication and control programs Spread: control and slow the spread --> fund slow-the-spread programs Ecological, human health, or economic impact: human adaptation (change behaviour and bear the costs) --> establish national center for invaisce species management

Question 34

What are 4 screening questions that can be used to evaluate invasive species?

Answer 34

Is the spcies adapted for aquaculture or ornamental purposes? Has the species become naturalized where introduced? Does the spcies have invasive races/varietes/sub-species? Is the species reproductive tolerance suited to climates in the risk assessment area?

Question 35

What are some ways to control pest management?

Answer 35

Manual (traps) Chemical (herbicides, pesticides) Biological (natural predators/parasites) Genetics, mRNA

Question 36

What is biodiversity?

Answer 36

The variability of life on Earth The variability among living organisms from all sources including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems

Question 37

How does habitat change/loss impact biodiversity?

Answer 37

Decreases population sizes --> more vulnerable to extirpation

Question 38

What are some factors that are participating in biodiversity loss?

Answer 38

Pollution Invasive species Cliamte change Overexploitation Habitat loss

Question 39

Why should we care about biodiversity loss?

Answer 39

Ethics/value of life Medical Ecosystem services - direct (resources such as food) - indirect (envr. modification, coral reefs) - lifestyle (recreation) Culture

Question 40

Break down total economic value in use value and non-use value

Answer 40

Use value: - Direct use value: provisioning services, cultural services - Indirect use value: regulating and supporting services Non-use value: provisioning, cultural, regulating and supporting services - Existence value - Option value - Bequest value

Question 41

What are some examples of ecosystem services?

Answer 41

Provision of food, fuel and fibre Provision of shelter and building materials Purification of air and water Detoxification of air and water Stabilization/moderation of climate Moderation of floods, droughts, temp. extremes, and forces of wind Generation and renewal of soil fertility, including nutrient cycling Pollination of plants Control os pests/diseases Cultura/aesthetic benefits etc......

Question 42

What are the consequences of ecosystem services?

Answer 42

Promotes the protection of only certain biota For instance, only 15 plants and 8 animal species supply 90% of our food Yet biodiversity is about variations

Question 43

How is diversity (species richness) related to biomass? Niche Complementary hypothesis

Answer 43

More diversity (not overlapping) increases biomass However, overlap in niches that they occupy leads to no additional benefit to biomass (biodiversity richness) - redundacy leads to stability in biomass Therefore, positive but saturating relation between diversity and biomass (diversity can affect productivity)

Question 44

Is a simple ecosystem with few species at each trophic level better than an ecosystem with multiple species?

Answer 44

In the 50s and 60s it was believed that the more pathways there are, the less severe the failure of any one pathway In the 70s and 80s, it was believed that the more complex systems were less stable Now, we believe that it depends upon the type of interaction and the strength of the interaction --> it is more nuanced

Question 45

What is the spatial insurance hypothesis?

Answer 45

Local diversity may be maintained by immigration from the region which provides the source of variation (species or genetic diversity) that can buffer ecosystem processes against environmental variation - ability to recover because of the diversity in a spatial context If many sites are considered (as in a metapopulation) then differences in the timing of biomass fluctations can average out across space; a form of regional stability

Question 46

What happens to number of pests as biodiversity increases?

Answer 46

It decreases

Question 47

What are some sources of uncertainty for the links between species richness and ecosystem services?

Answer 47

Mismatch between functions measured and final ecosystem service Mismatch between the study conditions and actual management conditions and service delivery to society Studies insufficiently comprehensive to assess the different processes underpinning ecosystem-service supply Simultaneous effects of different components of biodiversity (richness, composition, functional diversity) Confounding environmental factors other than richness that contribute to effects on service supply Trade-offs between positive and negative effects of richness of the various functions underpinning service supply Context-dependent patterns

Question 48

What are some issues with the Endangered Species Act?

Answer 48

There is an increasing number of species listed, however it is unclear whether newly listed = newly endangered Also few removed, unclear whether extinctions, errors, recovered