Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
204 Cards in this Set
- Front
- Back
Rare species (Most Vulnerable);
rare can mean: |
(1) Narrow geographic Range
- only exists in small/constricted area in the world (2) Occupies only one of a few specific habitats - habitat specialists - availability of habitat in which they specialize (3) Found only in small populations - Random chance: small populations are more affected than large populations by catastrophic events (4) Combinations of (1) to (3) |
|
Endemic species
|
- often by definition rare
- occur in only one location |
|
An extremely important factor in conserving biodiversity because you only have one chance to protect
|
What is endemism?
|
|
Geographic isolation (islands, mountaintops, lakes) tends to generate ___________.
|
Endemism
|
|
Why are endemic species so vulnerable on islands?
|
Limited space and habitat
|
|
"Endemic to Saskatchewan"
|
Exists in Saskatchewan and nowhere else in Canada, but may still occur in the U.S.
|
|
Major factors that elevate extinction risk (5)
|
(1) Narrow geographic range
- vulnerable to habitat loss; nowhere to disperse to; no source populations to recolonize (2) Only one or a few populations - linked to (1) - vulnerable to stochastic events, human disturbance, or combination (3) Small population size - vulnerable to stochastic events, demographic changes, disease - loss of genetic variation, ability to adapt (4) Declining population size - something is causing reduced numbers; will likely proceed to extinction without intervention (5) Hunting/harvesting - difficult to manage; potential for rapid reduction in population sizes |
|
Other factors that increase extinction risk (7)
|
(1) Body size
- Big animals go extinct more often (2) Home range size - Need for large area (foraging/breeding) increases chances it will be affected by humans - needs more space = higher chance of extinction (3) Dispersal capacity - Inability to relocate following environmental stress/change elevates risk (4) Seasonal Migration - Depend on 2 major habitats and linkers; high probability of impact by humans - Cumulative effects of changes in all habitats (5) Genetic variability - Low variability = reduced ability to adapt (6) Niche requirements - Specialists tend to go extinct; lack flexibility - (Generalists adapt more readily) - E.g.: Ring-billed gull (7) Aggregations - Colonial/schooling/herding species at higher risk - More vulnerable to local effects (large groups eliminated at once) - E.g.: Sick pelican. Match in fire. |
|
Why are large animals more at risk of extinction than small animals?
|
- large individual ranges
- low reproductive rates - require more food - hunted by humans |
|
What does IUCN stand for?
|
International Union for the Conservation of Nature
|
|
IUCN vision:
|
A just world that values and conserves nature
|
|
IUCN mission:
|
Influence and assist societies to conserve the integrity and diversity of nature; ensure use of natural resources is equitable and sustainable
|
|
What are the IUCN categories? Describe.
|
- Extinct (EX): variety no longer known to exist
- Extinct in Wild (EW): exists only in cultivation, captivity, or naturalized population outside range - Critically Endangered (CR): extremely high risk of imminent extinction - Vulnerable (VU): Hgh risk of going extinct - Near Threatened (NT): close to qualifying as facing extinction, but not there yet - Least Concern (LC): usually widespread and abundant; little risk of extinction - Data Deficient (DD): not enough information to assess |
|
Narrow geographic range:
|
Only exists in small/constricted area in the world
|
|
Habitat specialists:
|
Occupy only one or few specific habitats
|
|
Why are narrow geographic ranges a major factor in elevating extinction risk?
|
- Vulnerable to habitat loss
- Nowhere to disperse to (in case of catastrophe, etc.) - No source populations from which to recolonize |
|
Why is having only one or a few populations a major factor in elevating extinction risk?
|
- Highly vulnerable to stochastic events, human disturbance, or combination
|
|
Why are small population sizes a major factor in elevating extinction risk?
|
- Vulnerable to stochastic events, demographic changes, disease
- Loss of genetic variation (ability to adapt) |
|
Why is a declining population size a major factor in elevating extinction risk?
|
- Something is causing reduced numbers; will likely proceed to extinction without intervention
|
|
Why is hunting/harvesting a major factor in elevating extinction risk?
|
- Can be difficult to manage; potential for rapid reduction in population sizes
|
|
Why is body size an 'other' factor in increasing extinction risk?
|
- Large animals go extinct more often because they require larger ranges, more food, have low reproductive rates, and are hunted more frequently
|
|
Why is home range size an 'other' factor in increasing extinction risk?
|
- Need for large area to forage/breed increases chances it will be affected by humans
- Needs more space = higher chance of extinction |
|
Why is dispersal capacity an 'other' factor in increasing extinction risk?
|
- Inability to relocate following environmental stress/change elevates risk
|
|
Why is seasonal migration an 'other' factor in increasing extinction risk?
|
- Depend on 2 major habitats and linkers; high probability of impact by humans
- Cumulative effects of changes in all habitats |
|
Why is genetic variability an 'other' factor in increasing extinction risk?
|
- Low variability = reduced ability to adapt to new diseases or changing climate
|
|
Why are niche requirements an 'other' factor in increasing extinction risk?
|
- Specialists tend to go extinct; lack flexibility
- Generalists adapt more readily |
|
Why are aggregations an 'other' factor in increasing extinction risk?
|
- Colonial/schooling/herding/etc. species are at higher risk
- More vulnerable to local effects (Large groups eliminated at once) |
|
What does the IUCN do?
|
- Conservation science biodiversity and how it links to human well-being
- Runs thousands field projects globally to better manage natural environment - Helps implement laws, policy, and best-practice - Maintains global database on species status |
|
IUCN bases their assessments on (a) qualitative or (b) quantitative assessments? In the absence of data, how are assessments made?
|
(b) quantitative assessments; subjectively
|
|
IUCN Red List Index
|
tracks the status of listed species over time; does it improve?
|
|
Living Planet Index
|
Follows population sizes for sample of vertebrates; do they increase?
|
|
Blue List
|
Swiss database of listed species that remain stable or have increasing population sizes
|
|
What does COSEWIC stand for?
|
Committee on the Status of Endangered Wildlife in Canada
|
|
What does COSEWIC do?
|
- Recommends status/listing to federal Minister of Environment
- Species designated by COSEWIC may qualify for legal protection and recovery under SARA - COSEWIC's assessments do not consider political, social, or economic factors |
|
What are the COSEWIC categories? Describe.
|
Extinct (X) - No longer exists
Extirpated (XT) - No longer exists in the wild in Canada, but exists elsewhere Endangered (E) - facing imminent extirpation or extinction Threatened (T) - Likely to become endangered if nothing is done to reverse the factores leading to its extirpation or extinction Special Concern (SC) - May become threatened or endangered because of biological characteristics and identified threats Data Deficient (DD) - Available information insufficient Not at Risk (NR) - Found not to be at risk of extinction given the current circumstances |
|
COSEWIC's process (3 steps)
|
(1) Develop list of candidate species
- Identify, assess eligibility, prioritize (2) Commission status report - Contract, review, approve (3) Assessment and designation - Status warranted according to established quantitative criteria |
|
What is Ne?
|
Effective population size; only those that breed and contribute to the gene pool
|
|
Ideally, in terms of small populations, we should protect as many individuals and as much habitat as possible. What is the reality?
|
Find minimum # individuals and habitat required for persistence and stay above this if possible
|
|
What is MVP?
|
- Minimum Viable Population
- Smallest isolated group with 99% probability of being extant in 1000 years - Attempts to account for demographic, environmental, and genetic stochasticity - Quantitative! - Must account for extremes - MVP analysis requires detailed demographic and environmental study |
|
Populations with MVP>10,000 are described as what?
|
Extremely variable
|
|
MVPa
|
Based on adult population size
|
|
MVPk
|
Based on carrying capacity assumptions
|
|
MVPne
|
Based on genetic effects
|
|
R0 = growth rate potential
High R0 = High/low MVP? Low R0 = High/low MVP? |
High R0 = Low MVP
Low R = High MVP |
|
How do long, careful studies affect MVP estimates?
|
They result in higher MVP estimates because they are more accurate
|
|
MDA
|
- Minimum Dynamic Area
- Amount of suitable land area required to support MVP. - Based on home range size of individuals |
|
Factors Affecting Small Populations (3)
|
(1) Loss of genetic variation
- Diversity of alleles influences ability to adapt (2) Demographic variation - Small populations are subject to random changes in demographic processes (3) Environmental variation - Small N subject to changes in demographic processes caused by environmental change |
|
Genetic drift:
|
- Random changes in allele frequency over time
- Separate from natural selection - Can easily cause rare alleles to be lost from gene pool |
|
H = 1-[1/(2Ne)]
What is H? |
Proportion heterozygosity remaining after one generation
|
|
Why is loss of genetic variation a factor affecting SMALL populations?
|
Most of the heterozygosity in a small population would be lost in a small number of generations
|
|
What do mutation and immigration do in terms of loss of genetic variation in small populations?
|
- Counter effects of genetic drift
- Bring new alleles (heterozygosity) into population |
|
Why can mutation alone not counter genetic drift?
|
- It occurs at a background rate that's relatively slow
- Realistic mutation rates are not high enough to prevent drift - Need immigration!! |
|
At Ne<100, how many immigrants per generation can counter drift?
|
1-2
|
|
Bigger population size means more or less heterozygosity? Is this good or bad for biodiversity? Why?
|
- More
- Good - Heterozygosity is a measure of biodiversity |
|
Inbreeding depression:
|
- Decrease in fitness from loss of genetic variation (because individuals are too similar)
- Caused by mating among individuals sharing alleles common in descent - Unmasks harmful recessive alleles, which leads to reduction in fitness |
|
Outbreeding depression:
|
- Decrease in fitness caused by mating with individual of different species (because individuals are too different from one another), or highly divergent population
|
|
Why do we suffer from reduced heterozygosity?
|
Inbreeding and outbreeding depression
|
|
Rare/threatened populations are small, vulnerable to effects of drift and loss of fitness. What kind of effect can this cause?
|
- SPIRAL!
- decrease Ne = decrease H = decrease Ne = etc... - If population is not big enough, eventually you'll hit zero (extinct) |
|
50/500 Rule:
|
50 individuals needed to avoid short-term inbreeding depression, 500 needed to balance mutation and genetic drift
|
|
Why is the 50/500 rule considered inadequate?
|
Need several thousand individuals, not 50 and 500
|
|
Muller's Ratchet:
|
- Small populations tend to randomly incorporate/accumulate deleterious mutations
- Loss of variation = reduced pop. size = further loss of variation = etc... (SPIRAL) |
|
Ne << N when...(3)
|
(1) High variance in reproductive output
- e.g.: hormones in wastewater (2) Unequal sex ratio - e.g.: hunting (3) Population fluctuation or bottleneck - e.g.: harvest, habitat loss |
|
Loss of genetic variation is based on what?
|
Ne
|
|
Why do few individuals actually have mean B or D?
|
Variance among individuals
|
|
What happens if there are variations in B and D in small populations?
|
Random changes to N
- If N decreases randomly because of low B or high D, resulting small population even more likely to decrease - Spiral of demographic changes leading to ever-reducing N; can lead to N=0! |
|
Low N can lead to altered sex ratio, which can lead to _________.
|
Reduced mating
|
|
Allee Effect:
|
Positive correlation between N and fitness
|
|
In terms of extinction risk, which is more important: environmental variation or demographic variation?
|
- Environmental variation.
- Changing environments can kill large % of small population in short time - MVP estimates change dramatically when environmental variation is considered - Death rates can be increased while, at the same time, birth rates can be decreased - Smaller N (due to environmental variation) now vulnerable to random demographic changes as well |
|
Extinction Vortex:
|
- SPIRAL!
- 3 major factors affecting small populations (genetic, demographic, and environmental variation) cascade to cause 'self-feeding' decline - small populations continuously decline towards extinction |
|
Factors affecting Ne (3)
|
(1) Reproductive variance
- High variance in # of offspring produced among individuals (2) Unequal Sex Ratio - Uneven number of males and females or extreme variance in mating success (3) Fluctuations and Bottlenecks - Ups and downs in N can affect Ne, which is most influenced by low counts |
|
Bottleneck:
|
Reduction in N causes loss of rare alleles and genetic diversity
|
|
In snake conservation, radiotelemetry is used for what?
|
(a) Tracking movement patterns
(b) Collecting data on snakes' macro-habitats |
|
What is kernel density estimate used for?
|
To find out the probability of locating an individual inside of its home range?
|
|
What is compositional analysis, in terms of snake conservation?
|
What snakes don't like (-), like (+), really like (++), and _________ (=)
|
|
What are the statuses of:
(a) Bull Snake (b) Eastern Yellow-Bellied Racer (c) Prairie Rattlesnake |
(a) Data-deficient
(b) Threatened (c) Assessment 2012 |
|
What are two stressors for snakes of southwestern Saskatchewan?
|
(i) They are poikilotherms (their body temperature resembles ambient temperature) so they have trouble in the winter
(ii) Anthropogenic stressors (e.g. habitat loss) |
|
What are the objectives of the snake research program? (4)
|
(1) Characterize movement and (macro) habitat selection
(2) Understand (micro) habitat selection (3) Evaluate population structure and connectivity in Canada (4) Facilitate conservation in Canada |
|
In snake conservation, what are the methods for characterizing movement and macro-habitat selection?`
|
(i) Snake Capture
- Exclusion fence - Venomous snake handling (ii) Transmitter Implant - Surgically implant (iii) Radiotelemetry - Determine home range size, daily and seasonal movement, activity centres, habitat selection |
|
Is knowing snakes' movement patterns and location enough to be able to determine what areas must be conserved? Why or why not?
|
No; we still don't know what, specifically, is in those areas that snakes require for survival
|
|
What is the logistic growth equation?
|
dN/dt = rN[(K-N)/K]
|
|
(a) What is 'r' in the logistic growth equation?
(b) What are positive 'r' and negative 'r'? |
(a) rate of increase; average B-D
(b) population growth and decline, respectively |
|
From what do negative 'r' values (logistic growth equation) result?
|
Unbalanced ratio of births (B) to deaths (D) in a population
|
|
Altered ratio of B:D causing decline could be result of... (3)
|
(a) inappropriate conditions
(b) lack of resources (c) novel source of mortality |
|
When a population is declining, what can we assume about 'r'?
|
There is a issue with it that we need to fix!
|
|
Life history:
|
- Distinctive features of life cycle
- e.g.: mating system, reproduction, niche, etc. |
|
Population biology:
|
- Factors that influence distribution and abundance
- Related to life history |
|
For each species of conservation concern, we must know about... (6)
|
(1) Population trends
- stable, increasing, or decreasing? (2) Distribution and habitat - Where does species live? - Geography and specific habitats! (3) Demography and behaviour - Age distribution, reproductive output, social system, mating, how actions affect survival (4) Biotic interactions - Food and resources, actions of competitors/parasites/disease (5) Genetics - variation and its distribution (6) Interactions with humans - How do humans affect (1) through (5)? Influence extinction risk? |
|
What is "Grey" literature?
|
Literature that is not published in scientific journals (e.g.: government, etc.)
|
|
Census:
|
Complete count of all individuals (only available for certain types of species)
|
|
Survey:
|
- Systematic (repeatable) method to count or index abundance of species in given area
- For large, widely distributed populations: relative abundance |
|
Radiotelemetry:
|
- VHF transmitter attached to animal; receiver used to track signal
- Allows specific analysis of individual movement and habitat use - Small scale (m to several km) |
|
Satellite telemetry:
|
- GPS locator attached to animal; accumulates GPS coordinates, transmits to satellite for download
- Fine-scale resolution (m), but also global in scale for migration patterns |
|
Home range:
|
Area with a defined probability of occurrence of an animal during specified time period
|
|
MCP:
|
- Minimum convex polygon
- Shape with minimum sum of linkage distance for sides constructed around points |
|
Kernel estimates:
|
- Minimum area that includes a specified % of the volume of distribution of use
- Based on home range area as function of location - Fixed and adaptive |
|
PVA:
|
- Population Viability Analysis
- Statistical approach to determine the probability that a population or species will go extinct - Projects forward in time, predictive |
|
PVA can be modified to examine potential impact of changes resulting from... (3)
|
(a) Environment
(b) Demography (c) Human impacts |
|
What can PVA be used for?
|
- To make list of conditions to be avoided
- Determine MVP necessary to escape catastrophes |
|
Purple Gremlins (a species) were extirpated from South Park in 1990's. Reintroduction is desired. How do we determine if it is feasible? Be specific.
|
PVA! to assess important factors contributing to population persistence
- Start with construction of population growth model using observed field data... (1) Create deterministic model (issue b/c no extant population; need input) (2) Modify parameters in model and project forward (3) Identify key factors that influence extinction risk - Growth is negative or zero if % females producing offspring is <50%, and juvenile survival is low (0.002%) |
|
When reintroducing a species, persistence is highly dependent on what?
|
% females spawning in any given year, and juvenile survivorship
|
|
Sensitivity analysis:
|
Identifies parameters that most directly affect extinction risk
|
|
Metapopulation:
|
- "Population of populations"
- Many groups linked by some level of migration - Frequent extirpation and recolonization events - "Christmas lights" - Management is difficult! |
|
Source population:
|
- Core population with fairly stable numbers
- Contributes individuals (migrants) to other areas |
|
Sink population:
|
- Satellite populations that fluctuate in size based on # incoming migrants
- Dead ends |
|
Briefly describe one extra issue associated with metapopulations
|
Metapopulations need unoccupied sites to move into in addition to occupied ones
|
|
Major human threats to biodiversity (7)
|
(1) Habitat destruction
(2) Habitat fragmentation (3) Habitat degradation/alteration (4) Climate change - causes (1), (2), (3) (5) Over-exploitation (6) Invasive species introduction (7) Disease spread |
|
What is wrong about developed countries criticizing developing countries for not having better environmental and conservation policy?
|
Developed countries are huge consumer that fuel 'development' in other places (GLOBALIZATION!)
|
|
Globalization:
|
Inter-connectedness of resources and labour markets joining commerce for many countries worldwide
|
|
Ecological footprint:
|
Average land area needed to produce resources to support one person based on lifestyle
|
|
What is the ultimate result of resource use?
|
HABITAT DESTRUCTION
|
|
Average ecological footprint in the USA is ≈10Ha. Based on the total land area and the population size of the USA, it should be 2.19Ha. Where does this extra land come from?
|
- The developing countries!!
- Anyone with whom we have an international trade agreement...those people are using THEIR land to support US (GLOBALIZATION). - e.g.: clothing, palm oil |
|
What does globalization do in terms of ecological footprint?
|
Allows people to have a much larger footprint than land area locally available
|
|
How is the Canadian footprint limited?
|
- By climate
- We need to use heat (fossil fuels) to survive - We can aim to be more efficient in those uses! |
|
What is the primary threat to biodiversity?
|
Habitat loss
|
|
What is the most important means of conserving biodiversity?
|
Protecting habitat!
|
|
How much of arable land on earth has already been developed?
|
98%
|
|
Principle threats to habitat (7)
|
(1) Agriculture
(2) Commercial development (3) Water projects (4) Livestock production (5) Pollution (6) Roads/Infrastructure (7) Disruption of fire cycles |
|
Rainforest is (a) ____% of earth's land area, but (b) ____% of species
|
(a) 7%
(b) 50% |
|
How much of tropical rainforest globally has already been cleared for agriculture?
|
≈30%
|
|
What are the hotspots for rainforest decline?
|
Central America & Brazil, south-east Asia, Indonesia
|
|
How much of tropical forests outside of protected areas are predicted to be cleared in the next 50 years?
|
100%
|
|
What are the two types of clearing (in terms of rainforests)
|
(1) Large-scale industrial farming
- Conversion to cattle ranches - cash crops (2) Shifting cultivation - Subsistence farming for poor - often called 'slash and burn' |
|
Large-scale industrial farming:
|
- One of two types of rainforest clearing
- Conversion to cattle ranches - Cash crops |
|
Shifting cultivation:
|
- One of two types of rainforest clearing
- Subsistence farming for for poor - Often called 'slash and burn' |
|
How does clearing forests affect global climate change?
|
Forests are huge carbon sinks; the biomass in those forests holds massive amounts of carbon. When forests are cleared, the plants in those forests are destroyed (burned, turned to lumber, etc.), which releases that carbon into the atmosphere which can, in turn, affect climate change.
|
|
What are some highly threatened habitats (other than the rainforest)?
|
Tropical deciduous forests
- easy to clear, good soil fertility Grasslands - Crops Wetlands/freshwater - Filled for development - altered for industry and energy production Marine coastal areas - High human population density Mangroves (saltwater swamps) - Critical fish/shellfish nurseries - Cleared for aquaculture and rice Coral reefs - ≈33% of fish species Philippines - 90% of reefs already dead or dying |
|
Loss of habitat = loss of _______
|
BIODVERSITY
|
|
Desertification:
|
- Dry climates degraded by human activities become man-made deserts
- Repeated cultivation, livestock grazing reduce soil water retention properties |
|
What causes desertification?
|
Repeated cultivation and livestock grazing reduce soil water retention properties
|
|
What are the differences between fragments and original landscape? (3)
|
(1) Fragments have greater proportion of edge
(2) Centre of each fragment is close to an edge (3) Smaller area, smaller population sizes |
|
Habitat fragmentation is a result of...
|
- Agriculture
- Forestry - Urbanization |
|
Habitat fragmentation:
|
Breaking up of large continuous landscape into small isolated patches
|
|
Edge Effect:
|
- Altered conditions at edge of patch different from interior and main properties of habitat
- Fragmentation limits dispersal and colonization of patches - Fragmentation also changes foraging pattern in animals - Invasive species easier to establish at edges - Metapopulation dynamics disrupted (reduced potential for dispersal and colonization!) |
|
Some species at risk are not driven by habitat. What does this mean for recovery potential?
|
- High recovery potential!!
- e.g.: Easier to reduce hunting quotas than to regain lost habitat |
|
Main purposes of SARA (3)
|
(1) Prevent extinction/extirpation of Canadian species, subspecies, and distinct populations
(2) Recover endangered or threatened species (3) Encourage management of other species to prevent them from becoming at risk |
|
What are SARA's:
(a) Schedule 1 (b) Schedules 2 & 3 |
(a) Official updated list of SAR in Canada; legally protected species
(b) Species assessed prior to 1999; need to be updated using revised criteria; not legally protected by SARA |
|
What does it mean to be added to SARA's Schedule 1?
|
It is illegal to harass, capture, or kill an SAR that has been added to Schedule 1. Also illegal to destroy/alter critical habitat.
|
|
Critical habitat:
|
- That which is deemed necessary for the survival and/or recovery of a SAR
- Difficult to identify; intensive field studies - Legal term; can lead to legal conflicts, can be very expensive |
|
(a) Who enforces SARA?
(b) What are penalties? |
(a)
- Federal wildlife enforcement officers (Environment Canada) - Other policing agencies (b) - Financial and jail time |
|
Recovery team:
|
- Group of experts on species
- government, NGO, academics - Chaired by senior member |
|
What is a recovery strategy and what are the steps involved (4)?
|
A recovery strategy is an official document.
(1) Identify what needs to be done to stop decline (2) Set goals (3) Identify critical habitat (4) Describe research/management needed |
|
What are the objectives of conservation biology? (3)
|
(1) Document biodiversity on earth
(2) Investigate human impacts on: - ecosystems - species - genetic variation (3) Develop means to: - Prevent extinctiong - Maintain/restore ecosystem function - Maintain genetic diversity |
|
Normative discipline:
|
- Some kind of ideal
- We need a functioning ecosystem instead of free of evidence of humans |
|
Intrinsic value:
|
- Nature (biodiversity) has inherent value independent of its monetary worth to humans
|
|
Preservation ethic:
|
- Natural areas have spiritual values above what would be gained via exploitation
|
|
Principles of conservation biology (5)
|
(1) Diversity of species and ecosystems should be preserved
(2) Extinctions should be prevented (3) Ecological complexity should be maintained (4) Evolution should continue (5) Biodiversity has intrinsic (and monetary) value |
|
Biodiversity:
|
Complete range of biological communities, species, and genetic variation
|
|
What are the three levels of biodiversity?
|
(1) Ecosystem: variation in communities
(2) Species: member species in communities (3) Genetic: variation within species (allelic) |
|
Species richness:
|
- Measure of diversity
- Number of species in a given area |
|
Species concepts (3)
|
(1) Morphological species
- Group that is morphologically, physiologically, or biochemically distinct from other such groups (2) Biological species - interbreed, produce fertile offspring (3) DNA Barcoding - Aids taxonomy |
|
Alpha diversity:
|
Number of species in a certain community/designated area
|
|
Gamma diversity:
|
Number of species over a large geographic range
|
|
Beta diversity:
|
- Rate of change in species number over a gradient
- beta = gamma/alpha |
|
Population:
|
Group of individuals that interbreed; share common gene pool
|
|
(a) different genotypes x same environment = ?
(b) same genotypes x different environment = ? |
(a) different phenotypes
(b) different phenotypes |
|
Gene flow:
|
- Movements of alleles among populations
- Reduced in rare species |
|
Phyletic evolution:
|
Gradual development of new species from an ancestral form
|
|
Biological Community:
|
Species in an area and interactions among them
|
|
Ecosystem:
|
Biological community and physical and chemical environment
|
|
Keystone species:
|
- Small % of community biomass but determines the ability of large number of species to exist
- Often a predator; tends to be rare |
|
Keystone resources:
|
Occupy small % of area within system, but critical to biological community
|
|
Trophic cascade:
|
Change in one species changes connections among many in a food web
|
|
Succession:
|
Gradual change in ecosystem/community following disturbance
|
|
Loss of keystone resources leads to...
|
Loss of species, especially animals
|
|
Ecosystem Integrity:
|
- Condition of ecosystem in terms of species composition, structure, and function
- Difficult/impossible to quantify, but we know when it has been damaged - A system that has lost some species, or has changed as a result of human activities likely has reduced integrities |
|
Species Evenness:
|
- Distribution of individuals among different species in a community
|
|
Simpson Index:
|
- Measure of biodiversity
- D = 1/(∑pi^2) - High D = high diversity, even distribution - Low D = low diversity, skewed distribution |
|
(a) Homozygous:
(b) Heterozygous: |
(a) Will receive the same allele from each parent
(b) Will receive a different allele of the gene from each parent |
|
Shannon Weaver Index:
|
- H = -∑(pilnpi)
- High H = more uncertainty, more species with higher representation - Low H = less uncertainty, higher likelihood of sample 1 or 2 species |
|
Functional Redundancy:
|
In a complex food web, multiple species play same role
|
|
Biodiversity hotspots (4)
|
(1) Tropical rainforests
(2) Coral reefs (3) Large tropical lakes (4) Deep sea |
|
Why are there so many species in the tropics? (5)
|
(1) SOLAR ENERGY/HIGH PRODUCTIVITY provide larger resource base for more species (put more energy in, get more out of it)
(2) Long periods of ENVIRONMENTAL STABILITY provide time for diversification of species (3) CANOPY supports second ecosystem (4) COMPETITION is more intense, leads to heavy selection pressure for speciation (5) LARGE GEOGRAPHIC AREA, many niches |
|
Most threats to biodiversity are economic in nature. What can we assume about the solutions?
|
They must also have economic basis.
|
|
Economic Valuation:
|
Dollar value assigned to aspects of biodiversity
|
|
Externalities:
|
- Hidden costs/benefits
- Associated costs of benefits that affect individuals not directly involved in a transaction |
|
Open-access resources:
|
- Air, water, soil
- Essentially free, & often severely affected by negative externalities |
|
What would likely happen if we were to pay the true cost for products, including externalities?
|
It would reduce damaging activities.
|
|
Cost-benefit analysis:
|
Process compares cost vs. economic return, and it supposed to include environmental aspects
|
|
Precautionary Principle:
|
Better to err on the side of little or no environmental damage if uncertain
|
|
Perverse Subsidies:
|
Governments provide funds to promote industries that are losing money while causing loss of biodiversity (e.g.: agriculture, oil, fisheries)
|
|
Substitute cost approach:
|
Goods could be assigned $ value based on cost if required to purchase
|
|
Indirect use value:
|
$ value assigned to environmental and ecosystem services
|
|
Valuable ecosystem services (7)
|
(1) Productivity and Carbon sequestration
- Energy and carbon storage of 1˚ producers important for supporting non primary producers that are important to commerce (2) Water and soil protection - Plants and biomass can help prevent floods and stabilize topsoil (3) Waste treatment and nurtient retention - Aquatic diverstiy breaks down contaminants and cycle nutrients (4) Species interactions - Pollinators pollinate crops (5) Climate regulation - Loss of diversity = altered evapo-transpiration cycles, gas exchange (6)Recreation and ecotourism - Hiking, camping, photography, sport hunting, fishing, etc. - Ecotourism: people pay to see unusual biological communities (7) Other means of indirect use value - Option value: potential that biodiversity will yield valuable products or services in the future - Existence value: amount that people are willing to pay to ensure that species continue to exist |
|
Option value:
|
Potential that biodiversity will yield valuable products or services in the future
|
|
Existence value:
|
Amount that people are willing to pay to ensure that species continue to exist
|
|
Ethical values of biodiversity (2)
|
(1) Each species has a right to exist
- Intrinsic value (2) People have a responsibility to act as stewards - Religious rationale |
|
Extant:
|
Exists in natural population
|
|
Extinct:
|
No member of the species remains alive anywhere int he world
|
|
Extirpated:
|
Species no longer found in an area that it formerly occupied, but still in other areas
|
|
Ecological extinction:
|
Species exists in such reduced numbers that its interactions with others are negligible
|
|
Commercial extinction:
|
Species no longer abundant enough to be harvested on large-scale
|
|
There have been six major extinction events on earth. What is the sixth?
|
- Human impacts
- Started ≈30,000 years ago |
|
Punctuated equilibrium:
|
- Evolution occurs as period of stasis followed by explosive branching
- Stephen Jay Gould |
|
Sociobiology:
|
- Unified study of behaviour in all animals that incorporated genetics and environment
- Edward O. Wilson |
|
Approximately how long do species last?
|
1-10 million years
|
|
What is the actual modern extinction rate vs. the expected?
|
Actual = 0.50 spp/yr >> Expected = 0.0001-0.01 spp/yr
|
|
Extinction Debt:
|
Predicted eventual loss of species after disturbance; lag time to extinction
|
|
Island Biogeography:
|
- Way of predicting species number based on island area and proximity to mainland
- Species number based on dynamic equilibrium between immigration or evolution of new species, and extinction |
|
Why are island species especially vulnerable to extinction? (4)
|
(1) Small population sizes
(2) Limited range (3) Small number of populations (4) Evolved in absence of certain predators/competitors/diseases; no defences |
|
Species area curve:
S = CA^z A = ? C = ? z = ? |
A = Area
C = Constant based on taxa z = constant based on log-log slope (range 0.15-0.35; typically 0.25) |
|
(a) Species-area relationship:
(b) Why is this not perfect? |
(a) Larger islands have more species than smaller ones
(b) - Bigger islands have more species, but not a linear relationship - Constants used in equations are estimates - Land area is not the only variable that affects species number (e.g.: habitat, complexity, etc.) |
|
Why is island biogeography useful for conservation projects?
|
- Fragmentation creates 'islands' in an unsuitable matrix
- Insight into relationship between species number and land area - Protected spaces designed based on species-area relationships - Fragmentation/loss causes lost connectivity among patches; each behaves as its own 'island' |
|
90/50 Rule:
|
90% habitat loss = 50% species loss
OR: 10% habitat protection = 50% species protection |
|
What can happen at low N, in terms of demographic variation?
|
- Spiral of demographic changes leading to ever-reducing N
- Social systems, mating, ecological functions start to break down - Sex ratio may become altered, leading to reduced mating |