chapter 54 - biodiversity and conservation biology

Question 1

define genetic diversity

Answer 1

total genetic information contained within all individuals within a population
- number and frequency of all genes (and their alleles) present in a species

Question 2

breakthroughs in ability to catalogue genetic diversity

Answer 2

1. entire genome sequencing
2. environmental sequencing

Question 3

why is genetic diversity important?

Answer 3

represents the adaptive capacity of a group and its ability to persist despite changes in its environment

Question 4

dna barcoding

Answer 4

uses gene sequences to identify species
- nonspecialists can use it
- researchers can use it to identify leftover tissues

Question 5

taxonomic diversity

Answer 5

when species are a part of lineages with many species (e.g. Beatles and orchids)

other lineages are species poor (such as the red panda which is the sole species in its lineage) - high targets for conservation

Question 6

define ecosystem function

Answer 6

sum of the biological and chemical processes (e.g. carbon cycling, primary production) in an environment

Question 7

how many species are living today?

Answer 7

we don’t know!
estimated 5-100 million. only 1.5 million catalogued

Question 8

define species richness and species diversity

Answer 8

richness - # of species present in a given ecological community

diversity - variety and relative abundance of species in a. given ecological community

for a given species richness, diversity is high if evenness is high

Question 9

define endemic species

Answer 9

species that are found in a particular area of the world and nowhere else

Question 10

common trends in species richness and endemism

Answer 10

• richness highest in the tropics and declines towards the poles
• biodiversity higher on land than at sea
• greater geographic diversity = more diversity
• rainforests high in richness

Question 11

causes of species endangerment

Answer 11

• habitat loss
• invasive species
• over-exploitation
• pollution
• native species interactions
• natural causes

Question 12

habitat fragmentation

Answer 12

reducing habitats until they are too small to support some species like top predators

• loss of top predators can cause trophic cascades
• can force species into metapopulations
• leads to small, isolated populations vulnerable to catastrophes

Question 13

edge effect

Answer 13

biomass decreases sharply along the edges of forest fragments
- quantity and quality of habitat drastically decline
- early succession weedy species replaces large trees

Question 14

overexploitation

Answer 14

any unsustainable removal or organisms from the natural environment by humans

Question 15

name major threats to biodiversity

Answer 15

• habitat destruction and degradation
• overexploitation
• invasive species
• pollution
• climate change

Question 16

difference between exotic and invasive species

Answer 16

exotic - non native species introduced to an area
invasive - exotic species that has grown in size and disrupts native species

Question 17

species richness increases with ___

Answer 17

habitat area

Question 18

productivity of ecosystems depends on ____

Answer 18

number and types of species present

Question 19

define stability in a community and how to measure it

Answer 19

1. maintain productivity and other aspects of ecosystem function as conditions change over time
2. recover to former levels of productivity and richness after a disturbance

measured by…
- resistance (extend community remains unchanged by disturbance)
- resilience (ability to bounce back)

Question 20

connection between diversity, resilience and resistance

Answer 20

species diversity increases resistance and resilience!

Question 21

list ecosystem services

Answer 21

• provisioning (provide raw materials)
• regulating (earth’s life support system)
• cultural
• supporting (enable all other ecosystem services e.g. primary productivity, nutrient cycling, pollination, pest control)

Question 22

3 arguments to support ethics in preserving the environment

Answer 22

1. organisms have intrinsic worth
2. industrialized nations are responsible for most harm; should not infect harm on poorer nations
3. unethical for current generation to deprive future generations of ecosystem services

Question 23

impossible to preserve high species diversity if 2 things happen

Answer 23

1. population growth to 10 billion or more
2. fossil fuel and resource consumption does not decline

Question 24

strategies to preserve environment

Answer 24

• education campaigns
• genetic restoration
• seed banks
• management plans for invasive species
• management plans for endangered species
• in-situ conservation and reintroduction
• wildlife corridors
• designating protected areas
• ecosystem restoration
• quantifying ecosystem services (paying landowners not to destroy land)

Question 25

three levels that define biodiversity

Answer 25

genetic
species
ecosystem