Chapter 27 (B) & 37 (A)

Question 1

What are the 5 Hardy Weinberg Principles?

Answer 1

No mutations.
No genetic drift.
No gene flow.
Random mating.
No selection.

Question 2

What are the features of Natural Selection? (4)

Answer 2

Individual variation.
Inheritance.
Overproduction.
Differential reproductive success.

Question 3

How are cladograms constructed?

Answer 3

Cladistics—a method phylogeneticists use to construct a phylogeny called a cladogram.

Question 4

Prezygotic Isolation

Answer 4

(Reproductive)

In place before fertilization.
No attempt at reproduction.

Question 5

What are the benefits of diversity in a population?

Answer 5

Maintenance of genetic variation is beneficial.

Populations with limited variation may not be able to adapt to new conditions if the environment changes, and they may become extinct.

Variation can be maintained despite selection working to limit it.
> Forces that promote variation are still at work.
> Gene flow might still occur.
> Natural selection may favor certain phenotypes, but others still remain in smaller numbers.

Question 6

What are the principles of conservation biology?

Answer 6

Biodiversity is desirable for the biosphere and therefore for humans.

Human-induced extinctions are undesirable.

Complex interactions within ecosystems and communities support biodiversity and the maintenance of such interactions is therefore desirable.

Biodiversity generated by evolutionary change has intrinsic value, regardless of any practical benefit.

Question 7

genetic diversity

Answer 7

number of different alleles.

High genetic diversity increases capacity to adapt to environmental change.

Question 8

What are the reasons species go extinct?

Answer 8

(HUMANS)

Habitat loss (85%).
Exotic species (50%).
Pollution (24%).
Overexploitation (17%).
Disease (3%).

Question 9

What are the indirect values of conservation? (7)

Answer 9

Biogeochemical cycles – Biodiversity within ecosystems contributes to the water, carbon, nitrogen, phosphorus, and other biogeochemical cycles.

Waste disposal – Decomposers break down dead organic matter and other types of wastes.

Provision of fresh water – Terrestrial organisms especially need fresh water.

Flood prevention – Forests and other natural ecosystems exert a “sponge” effect.

Prevention of soil erosion – Intact ecosystems naturally retain soil and prevent its erosion.

Regulation of climate – Trees provide small- and large-scale benefits.

Ecotourism – Many people prefer to vacation in natural areas.

Question 10

What are flagship species?

Answer 10

These species evoke an emotional response from humans.

|&raquo_space;Lions, tigers, dolphins, giant panda.

Question 11

What are keystone species?

Answer 11

Loss of a keystone species would result in a great number of secondary extinctions.
»Wolves, bats, grizzly bears, beavers, elephants.

Keystone species are not necessarily the most abundant.

Question 12

Postzygotic Isolation

Answer 12

(Reproductive)

In place after fertilization.
Reproduction may take place, but no fertile offspring produced.

Question 13

Temporal Isolation

Answer 13

is an evolutionary mechanism that keeps individuals of different species from interbreeding, even if they live in the same environment.

Question 14

Behavioral Isolation

Answer 14

(Reproductive)

based on the behavior of species in the context of mating rituals and signals.

Question 15

Habitat Isolation

Answer 15

occurs when two species that could interbreed do not because the species live in different areas

Question 16

Mechanical Isolation

Answer 16

(Reproductive)

prevents two different species from interbreeding with one another.

Question 17

species diversity

Answer 17

number of species in a given area.

Question 18

conservation diversity

Answer 18

Described as the variety of life found on Earth.

The number of species in a given area or ecosystem.
> Approximately 1.6 to 1.7 million species have been described across the globe.

Question 19

landscape diversity

Answer 19

interacting ecosystems.

Fragmentation can reduce reproductive capacity by increasing predation risk.

Question 20

ecosystem diversity

Answer 20

interactions between species and their abiotic environment.

Conserve species that play critical roles in an ecosystem.

Question 21

What is the goal of conservation biology?

Answer 21

Conservation biology strives to reverse the trend toward the extinction of thousands of plants and animals.

Direct value - Individual species perform services for humans and contribute to the value we should place on biodiversity.