Midterm #1

Question 1

What is conservation biology? (Groom et al. 2006)

Answer 1

An integrative approach to the protection and management of biodiversity…

Question 2

List the 3 Guiding Principles of conservation biology

Answer 2

1. Evolution is the basis for understanding biology
2. Biological entities are complex and dynamic
3. Humans are part of the natural world and our activities range from highly destructive to restorative. Human presence must be included in conservation planning.

Question 3

G. Evelyn Hutchinson posited that the “evolutionary play” takes place in an “ecological theater” how can this be related to conservation biology

Answer 3

from that perspective, conservation biology works to maintain the actors (organisms) in the evolutionary play and the ecological stage (the world) on which it is performed

Question 4

The Principle of Population from Malthus

Answer 4

The rate of food production is increasing linearly while the population is increasing exponentially over time until it reaches a point where the population exceeds the rate of food production (where those lines intersect).

Question 5

What is the truth about the global growth rate?

Answer 5

The growth rate is slowing despite the population increasing, the slope of increase is becoming less steep (peaked in 1968 at 2.1% but predicted to decrease to 0.1%). Per capita CO2 emissions also vary depending on country (highest in North America and Asia).

Question 6

List the 5 major eras of conservation activity in the last 150 years

Answer 6

1. disappearance of the Eastern Wilderness (1850-1865)
2. Closing of the Western Frontier (1890-1905)
3. Dust Bowl era (1930-1940)
4. Population explosion & environmental pollution (1960-1975)
5. Biodiversity crisis (1990-present)

Question 7

Describe Phase 1 (disappearance of Eastern Wilderness)

Answer 7

• forests that covered most of the US were replaced by farms and towns
  *Darwin’s “The Origin of Species” in 1859 placed humans as part of nature and emphasized that organisms are adapted to a particular environment and may go extinct if the environment changes
  *Henry David Thoreau suggested every township should have a park- Central Park was later established

Question 8

Phase 2 (closing of the western frontier)

Answer 8

*Western settlement reached the Pacific and ecology was emerging
*John Muir is America’s most influential naturalist/conservationist who was the first president of the Sierra club and petitioned for the National Park bill
*several federal agencies were established to manage natural resources
*Canada’s first national park was in Banff and the National Parks Act was created in 1930

Question 9

Phase 3 (dust bowl era)

Answer 9

• population growth and great depression led to more farmers
  *the South was plagued by flood and erosions while the central plains went through drought in the 30s
  *John Steinbeck wrote the Grapes of wrath which highlighted human and environmental casualties of the Dust Bowl
  *Aldo Leopold- preserving the beauty of a community is right
  *Paul R Ehrlich- concerned about overpopulation and limited resources

Question 10

Phase 4 (environmental pollution)

Answer 10

*rachel carson - Silent Spring spoke of effects of humans in the environment through use of DDT

Question 11

Phase 5 (biodiversity crisis)

Answer 11

• sixth extinction
  *Michael Soule-cofounder of the society for conservation biology which is a “crisis discipline”

Question 12

What are the 3 hierarchy levels of biodiversity?

Answer 12

1. Genetic diversity
2. Species diversity
3. Ecosystem/biogeographic diversity

Question 13

What type of population retains high genetic diversity and what are the benefits?

Answer 13

Large populations retain high genetic diversity while small isolated populations lose genetic diversity.
Larger populations mean higher diversity which means:
- higher adaptive capacity
- potential for long-term survival
- high resilience

Question 14

Define genetic diversity. What is the difference between genetic diversity among species and genetic diversity within populations?

Answer 14

It reflects evolutionary history and shapes how it will evolve in the future.
among species- it determines phylogenetic relationships
within populations- used to identify forces acting on genetic variation

Question 15

Define evolutionary potential (adaptive capacity), what 2 actions can increase evolutionary potential?

Answer 15

*the capacity of a population to evolve in response to environmental change
1. minimizing inbreeding to increase the genetic variety
2. minimizing loss of genetic variation through genetic drift (avoiding small isolate populations)

Question 16

What are the steps of the extinction vortex?

Answer 16

1. Reduced N (population) due to catastrophes
2. Reduced Ne (effective population capable of breeding)
3. reduced evolutionary potential, increased inbreeding
   4.increased maladaptation
   5.reduced birth and survival rates

Question 17

What kind of species is most likely to survive best after the effects of climate change? What kind is least likely?

Answer 17

Species 3 will have most of its population survive bc it has both small and large populations that are adapted to a variety of climates and are not isolated. This is why they have the most evolutionary potential and the lowest extinction risk after warming.
Species 1 is least likely to survive because it is made up of small isolated populations that are only adapted to survive in the cold.

Question 18

Is focusing conservation legislation on the species level good or bad? Give examples (3)

Answer 18

Both good and bad because it saves species but does not focus on the ecosystem as a whole and address the complex issues affecting it. Also, we don’t know how many species there are in the environment so we don’t know how many to save.
1. CITIES - convention on trade in endangered species (global)
2. SARA- species at risk act (Canada)
3. ESA- endangered species act (USA)

Question 19

Describe the 2 common scales used to measure ecosystem diversity.

Answer 19

1. Richness= a single number that represents the number of diff species in an area, does not include component of relative abundance
2. Measures that include relative abundance:

Question 20

Describe the 3 types of measures of relative abundance which are used to measure ecosystem diversity. Provide examples for each.

Answer 20

a) alpha diversity= mean species diversity per subunit (ex. a patch of grassland)

b)beta diversity = rate of change of species composition among subunits (higher turnover rates make conservation more complicated) (ex. a forest)

c)gamma diversity = total species diversity over a landscape (ex. Canada)

Question 21

Describe the first way for mapping ecosystem diversity. What is a weakness of this method?

Answer 21

Divided by biomes along gradients in basic physical variables. The nicer the climate, the more diverse the community of species should be.
Weakness: does not separate various forms of grassland very well and says nothing about global diversity patterns (how many species, what species are there etc.)

Question 22

What kind of biome has the lowest diversity according to the first way of mapping ED and why? What about highest diversity?

Answer 22

polar desert communities have the lowest diversity because there are low rates of precipitation and decomposition (nutrients not available).
Rainforests have the highest diversity on the other hand.

Question 23

Describe the second way for mapping ED.

Answer 23

As latitude increases (equator = 0), species richness declines. This implies the equator has the highest species richness while 90N and 90S have the lowest. Ricketts et al. proved that as you go north from the equator, species richness decreases especially for birds and butterflies.

Question 24

Why can you dismiss the hypothesis that there are more species at lower latitudes because there are more habitat types?

Answer 24

Adiabatic lapse- at higher elevations in tropical areas are the same as cool climates in temperate areas, and at extremely high elevations, it is the same as being in the arctic. (ex. sky islands in Arizona have 8 diff biomes)
Being in a polar desert biome, there is no way to replicate the climate in tropical areas meaning overall habitat diversity in the tropics is greater than at higher latitudes.

Question 25

Why is there a higher within-habitat diversity at lower latitudes? List the 7 hypotheses.

Answer 25

1. Evolutionary time
2. Ecological time
3. Climate stability
4. Productivity
5. Species interaction
6. Species-area relationship
7. Evolutionary rates/speeds

Question 26

1. Describe the evolutionary time hypothesis. What does it assume? Why does this work for the NH but not the SH?

Answer 26

Diversity increases with a community’s age.

Assumes temperate and extreme latitudes remain impoverished as a result of previous glaciation cycles. Assumes both NH and SH are in the progress of restoring from the most recent glacial period.

Works for NH but not the SH because places like Africa were unaffected by the glacial period

Question 27

2. Describe the ecological time hypothesis. Why would this be incorrect?

Answer 27

The immigration of species displaced by glaciation may be why there are more species south of the NH. As the ice came, they migrated south.
May be incorrect bc many areas in the NW Territories have been exposed for 4000 years and plant species are still recolonizing.

Question 28

3. Describe the climate stability hypothesis. Why would this be incorrect?

Answer 28

Species living in stable climates (the equator) may evolve specialized adaptations to that specific climate. This is why those at the equator are the most diverse (narrower niches).

Those that live in unpredictable climates (NH) must have broad tolerance limits and broad niches. Hardy jack-of-all-trade species don’t have anywhere else to be but the NH. (broad niches = lower diversity)

Question 29

4. Describe the productivity hypothesis.

Answer 29

With more resources, there will be a greater number of individuals in that habitat. A greater number of individuals also means a greater number of species.

Sunlight is a resource and is greatest at the equator and decreases at the NH and SH which is why species abundance is greatest at the equator.

Question 30

5. Describe the species interactions hypothesis. How can competition and predation create diversity?

Answer 30

If competition is intense, natural selection will create populations with differentiated niches. Specializations that result from competition leave narrower niches and greater diversity.
Predation decreases the number of dominant species which reduces competition and allows for coexistence amongst many species.

Question 31

6. Describe the species-area relationship hypothesis. What is the assumption?

Answer 31

Rosenzweig believed total tropical habitat was larger than any other ecoclimatic zone which meant more species. Larger areas were assumed to have higher speciation rates, lower extinction rates and higher diversity.

Question 32

List the 3 criticisms of the species-area relationship hypothesis.

Answer 32

1. there’s no relationship btwn species’ range size and the habitat area available in a biome (more land does not mean more habitat area)
2. there’s no relationship btwn species’ range and speciation rate (more land does not mean more species)
3. there’s support for decreased extinction rate with decreased habitat area (more land does not mean less extinction)

Question 33

7. Describe the evolutionary rates/speed hypothesis.

Answer 33

Higher temps in the tropics increase speciation rates bc generation times are lower.
Higher temps and/or UV levels in the tropics give rise to higher mutation rates leading to higher diversity potential.

Question 34

Define PD (phylogenetic diversity) versus ED (evolutionary distinctness) according to Jetz et al. 2014. What makes the PD high?

Answer 34

PD- sum of all lengths of all branches in a defined phylogenetic tree (we want to save the branches if there are lots of very old species because it contains a lot of unique evolutionary history (high PD))

ED- The ED of all species in a tree sums up to be the PD. It is a species-level measure representing the weighted sum of the branch lengths along the path from the root of a tree to a given tip (species). Identical to and sometimes referred to as the fair proportion metric (FP).

Question 35

Difference between EDGE (evolutionary distinct and globally endangered) and EDR (evolutionary distinctness rarity)

Answer 35

EDGE-metric combines distinctness and extinction risk.

EDR-ED/species’ global geographic range size

Total EDR= summed EDR of all species co-occurring in a given location