Chapters 59 and 60 (Biodiversity and Conservation Biology)

Question 1

Why is a high amount of genetic diversity beneficial for a population? Why are small
populations more susceptible to loss of genetic diversity?

Answer 1

Populations with a greater amount of genetic diversity are better able to adapt to changing environmental conditions. Natural selection relies of differences between individuals in a population, and the more differences are present, the more opportunity for natural selection.

Small populations are more susceptible to loss of genetic diversity through genetic drift
(changes in allele frequency due to random chance) and inbreeding (inbreeding reduces the fitness of a population, and inbreeding is more likely in a small population where there is less choice of a mate).

Question 2

What is an endangered species? What is a threatened species?

Answer 2

An endangered species is in danger of extinction throughout a significant portion of its range. A threatened species is likely to become endangered in the near future.

Question 3

What is habitat destruction and how can it negatively affect species?

Answer 3

A natural habitat is altered in such a way that it can no longer support the species that were originally present. It affects species because species lose the habitat in which they lived and relied.

Question 4

What is overexploitation. Give two examples.

Answer 4

A species is harvested at an unsustainable rate (i.e., the species is killed at a faster rate than it can be replaced through reproduction).

Question 5

What is an introduced species? What is an invasive species? What are the 3 ways that
invasive species can negatively affect native species?

Answer 5

An introduced species is moved by humans from its native location to a different location in which it is not native. Some introduced species become invasive species, which negatively affect native species in the habitat into which the invasive species was introduced. Invasive species can negatively affect native species by:

• Providing competition: many invasive species can outcompete native species for
  resources, so there are not enough resources for native species.
• Predation: many invasive species are a predator to a native species.
• Causing disease: some invasive species are a pathogen to native species and cause
  disease.

Question 6

What are megadiversity countries? Why are megadiversity countries often targeted in
conservation efforts?

Answer 6

Countries with the greatest number of species. Such countries may be targeted for conservation efforts because the efforts are expected to protect many species.

Question 7

What does it mean if an area is a hotspot for endemic species? Why are endemic hotspots often targeted in conservation efforts?

Answer 7

Endemic hotspots contain many endemic species that are not found in any other location outside the hotspot. Endemic hotspots may be targeted for conservation efforts because, if the habitats are destroyed, the endemic species will be extinct.

Question 8

Which habitats are targeted in the representative habitat conservation approach?

Answer 8

The approach targets to conserve a collection of habitats that represents all habitats because all habitats are unique and important.

Question 9

Which habitats are targeted in the last of the wild conservation approach?

Answer 9

The ‘last of the wild’ conservation approach directs conservation efforts at the habitats that have been least affected by human activity, including tundra and taiga habitats.

Question 10

Red mangrove trees grow along the shoreline in the tropics. Their roots protect the soil from erosion and offer protection to many small animals. Without red mangrove trees, the structure of the habitat would be much different: shoreline would erode, and many small animals would have nowhere else to shelter. What kind of species are red mangrove trees?

Answer 10

A keystone species. They play a critical role in maintaining the ecosystem, which would look a lot different without them.

Question 11

Lichens are a combination of alga and fungus growing together. Bushy lichens grow in clean air with low levels of sulfur dioxide. Leafy lichens tolerate some air pollution, and crusty lichens can survive with high levels of pollutants. If no lichens are present, it may be a sign of heavy air pollution. What type of species are lichens?

Answer 11

An indicator species. Their presence or absence can provide an indication of air quality.

Question 12

Tigers require large areas of forest. Protecting tigers also protects the leopards, boars, hares, antelopes, monkeys and other species that occupy the same forest habitat. What type of species are tigers?

Answer 12

An umbrella species. Protecting the tigers will protect all other species within the large
habitat.

Question 13

The Zanzibar red colobus monkey is endemic to the island of Unguja and is listed as endangered. It features on the logo of a conservation organization in Zanzibar? What type of species is the Zanzibar red colobus?

Answer 13

A flagship species. It acts as an ambassador for the conservation organization in Zanzibar.

Question 14

What is the aim of restoration ecology?

Answer 14

The repair or restoration of biological habitats or their populations.

Question 15

What is captive breeding?

Answer 15

Species that reach a critically low population size are reared and bred in captivity with the
aim of eventually releasing them back into the wild to restore their numbers.

Question 16

What is the difference between habitat replacement, habitat rehabilitation and ecosystem replacement?

Answer 16

In habitat replacement, a habitat is restored to its former condition. In habitat rehabilitation, a habitat is restored to close to its former condition (i.e., it resembles its former condition), but the habitat will never be the same as before. In ecosystem replacement, an ecosystem is replaced by a completely different ecosystem than was there previously.