conservation biology

Question 1

what is it

Answer 1

predicting how a species will react to current/future changes, human caused, in its environment./density/distribution- whether it will survive and what to do to prevent extinction

Question 2

Goals in biodiversity

Answer 2

investigating human impacts on biodiversity

Develop approaches to prevent biodiversity loss

Question 3

Interconnected levels biodiversity loss occurs at

Answer 3

loss in genetic diversity
loss in species diversity
ecosystem loss

Question 4

Background extinction patterns

Answer 4

the long pattern of ecosystem change that leads to some species going extinct

Question 5

Mass extinction patterns

Answer 5

Catastrophic spikes of extinction associated with sudden widespread ecosystem change

Question 6

Even when species don’t go extinct,

Answer 6

their populations get smaller
-reduction in effective population size
Smaller populations do go extinct

Question 7

4 major threats most species loss can be traced to

Answer 7

Habitat loss or degradation (incl pollution)
Introduced species (incl disease)
Overexploitation (harvesting/hunting)
climate change

Question 8

Habitat loss and degradation

Answer 8

largest threat
Land suitable for agriculture has be mostly transformed (98%)
73% species gone endangered or extinct

Question 9

Fragmentation

Answer 9

Process by which a large continuous area is reduced and divided into 2 or more isolated patches
Causes reduction in pop sizes and genetic diversity, incr likelihood local and eventually global extinction

Question 10

Habitat degradation

Answer 10

Pollution: land, air and water

Question 11

Land pollution

Answer 11

release of chemicals leaves vast areas unusable for organisms

Question 12

Air pollution

Answer 12

Large scale effects leading to widespread complex ecosystem alteration

Question 13

Water pollution

Answer 13

Eutrophication and dead zones

Question 14

Why can introduced species be a problem?

Answer 14

displace native species
Have fewer predators/pathogens
Disrupt ecosystem function
Reduce overall diversity
Transmit disease (native organisms often have limited resistance to  novel pathogens)

Question 15

Over exploitation

Answer 15

Human taking of wild plants or animals and rates that exceed the system’s ability to replace them
Large organisms with slow reproductive rates are particularly susceptible
Aquatic and terrestrial systems are both susceptible

Question 16

Overfishing

Answer 16

Most fisheries are overexploited (not sustainable)

‘bycatch’ kills lots of nontarget animals- 25% of catch is returned to the sea to die

Question 17

climate change

Answer 17

species distribution is limited:
energetic costs
resource availability
Fitness under higher optimal conditions

Question 18

If climate conditions change, few possible outcomes:

Answer 18

-range shifts
-plastic responses (phenotypic plasticity-e ability of a genotype to express a different phenotype under different environmental conditions,)
-adaptive evolution ( shift in allele frequencies leading to a change
in phenotype in a population)
-extinction

Question 19

Warming oceans- impact on fish

Answer 19

Marine species moving away from equator to cooler waters, and replacing fish caught in fisheries
Subtropic and temperate ocean: as open temps rise, catch composition in the subtropic and temperate areas changed to include more warm-water species and fewer cool-water species
Tropics: catch composition changed then stabilised, likely because there are no species with high enough temp preferences to replace those declining

Question 20

Pop extinction is certain if

Answer 20

in the long term, the mortality and/or emigration rates are higher than the birth and/or immigration rate

Question 21

Extinction mechanisms act by

Answer 21

affecting the migration, mortality and BRs

Question 22

Extinction mechanisms 3 categories

Answer 22

demographic uncertainty
Environ uncertainty
Loss of genetic diversity

Question 23

Metapopulations

Answer 23

Fragmented population occupying spatially separate habitat patches

Question 24

source/sink modelling

Answer 24

source populations provide an excess of individuals which emigrate to and colonise sink subpopulations

Question 25

Metapopopulation survival depends on

Answer 25

• Local population survival (affected by genetics, patch size and quality)–> incr with patch size
• Unoccupied suitable habitat at suitable distances
• sufficient migration for colonization of unoccupied habitat ot occur- incr with small distances and corridors

Maintenance of dispersal key

Question 26

Natural habitat corridors particularly important for

Answer 26

large animals

Question 27

Genetic factors affecting small populations

Answer 27

genetic drift, founder effects, bottleneck effects,inbreeding depression

Question 28

Genetic drift: significant in, what does it incr likelihood of

Answer 28

Change in allele freq in a pop due to random sampling
Effects significant in small populations (random sampling of poor alleles leads to chance of extinction)
Genetic drift incr likelihood that alleles are lost, reducing genetic variation in a pop

Question 29

Effective pop size (Ne) estimated by

Answer 29

Ne= (4NfNm)/(Nf + N)

Where Nf and Nm are number of females, number of males that breed together successfully

Question 30

Founder effect

Answer 30

Occur when few individuals become isolated from larger pop to form a new one

Allele freq in small founder pop can be different from those in the larger parent one

Fragmentation can lead to reduced genetic diversity

Question 31

Bottleneck effect

Answer 31

Due to sudden reduction in pop size due to change in environment
Resulting gene pool no longer reflective of original pop’s gene pool
If pop remains small, it may be further affected by genetic drift

Question 32

Factors affecting small populations

Answer 32

Inbreeding depression- relative reduction in fitness of inbred progeny in comparison to equivalent outbred progeny

Mainly cause by concealed recessive deleterious mutations

Question 33

Link between drift/bottle neck and inbreeding

Answer 33

Reduction in no after drift/ bottleneck will incr likelihood of inbreeding increasing expression of deleterious traits (previously concealed) , causing fitness reduction