Conservation Biology

Question 1

What is a mass extinction? How many have there been and from how long ago?

Answer 1

A large fraction of all living species becomes rapidly extinct. Fossil record shows that at least five major mass extinctions have occurred in the past 500 million years.

Question 2

What are the five mass extinctions?

Answer 2

1. Ordovician-Silurian Extinction (Marine)
2. Late Devonian Extinction (fish)
3. Permian-Triassic Extinction (Trilobites)
4. Triassic-Jurassic Extinction (mammals, reptiles)
5. K-Pg Extinction (Dinosaurs)

Question 3

What are the three types of extinction and how do they differ?

Answer 3

Background extinction: affect one or a few species and occurring in one locality rather than globally

Mass extinction: sudden, global extinctions that affect many species

Anthropogenic extinction: extinction of many species due to environmentally destructive human activities

Question 4

What is conservation biology?

Answer 4

Integrates ecology, physiology molecular biology, genetics, and evolutionary biology to conserve biological diversity at all levels.

Question 5

What is the difference between genetic diversity and species diversity?

Answer 5

genetic diversity: genetic variations within a population or between populations (Gene pools)

Species diversity: variety of species in an ecosystem; includes species richness and species evenness

Question 6

What does the conservation of biodiversity require?

Answer 6

Integration of the principles of ecology, as well as social, political, and economic systems

Question 7

Difference between extinction and extirpation?

Answer 7

Extinction: species ceases to exist globally

Extirpation: species ceases to exist in a particular area, but exists elsewhere

Question 8

Difference between endangered and threatened species?

Answer 8

Endangered: a species that is at immediate risk of extirpation or extinction

Threatened: species likely to become endangered if limiting factors are not reversed

Question 9

What are threats to biodiversity?

Answer 9

1. Habitat destruction (73% of all extinction)
2. Introduced species
3. Overharvesting (overexploitation)
4. Global change

Question 10

What are introduced species? How are they threats?

Answer 10

Species humans move from native locations to new geographic regions.

Without their native predators, parasites and pathogens, the introduced species may spread rapidly and disrupt adopted community.

Question 11

What is overharvesting and two examples? Who is prone to it?

Answer 11

Human harvesting of wild plants or animals at rates of exceeding ability of populations of those species to rebound. Large animals with low reproductive rates are vulnerable to overharvesting. (e.g. poaching, overfishing)

Question 12

What is climate change causing?

Answer 12

Acid rain, Eutrophication, and Greenhouse effect.

Question 13

How does acid rain occur?

Answer 13

Chemical reaction as a result of SO2 and NO from burning fossil fuels are released into the air

Question 14

What is eutrophication?

Answer 14

Process in which a water body becomes overly enriched with nutrients, leading to plentiful growth of simple plant life

Question 15

What is the greenhouse effect?

Answer 15

Occurs when greenhouse gases in a plant’s atmosphere insulate the planet from losing heat to space, raising its surface temperature

Question 16

What is an extinction vortex?

Answer 16

A theoretical scenario where environmental and demographic forces, as well as genetic drift and inbreeding interact through time to push a population towards extinction.

Question 17

What is inbreeding and how does it reduce fitness in a small population?

Answer 17

breeding closely related animals, especially over many generations. It reduces fitness by increasing homozygocity of harmful recessive traits.

Question 18

What is the minimum viable population size?

Answer 18

Minimum population size at which a species can survive, estimated using computer models that integrate many factors that affect population growth rate.

Question 19

What constitutes an effective population size?

Answer 19

A subset of successful breeders (M/F) among the minimum viable population.

Question 20

What is a population viability analysis?

Answer 20

set of ideas, theoretical models, and conceptual and computational tools ecologists use to understand extinction risk of a species and to forecast future scenarios of population growth and decline

Question 21

What must be known for a population viability analysis?

Answer 21

1. Habitat requirements of a species
2. Population structure of a species
3. Life histories and behavioural ecology of a species

Question 22

What is the difference between a small population approach and a declining population approach?

Answer 22

declining population: identification and management of the processes that cause a species populations to decline deterministically.

small population: study of the largely stochastic factors that can result in the extinction or degradation of small populations.

Question 23

What are the steps of a declining-population approach?

Answer 23

1. Confirm the population is in decline
2. study species’ natural history
3. Develop hypotheses for all possible causes of decline
4. Test hypotheses in order of likeliness
5. Apply results to manage for recovery

Question 24

What is captive breeding? Why is it difficult?

Answer 24

A last resort strategy to breed animals within a controlled environment, as opposed to their natural setting in the wild.

It is difficult because many species do not breed in captivity and the remaining individuals may be related.