A population of birds is found on a remote island. Which of the following information is most important in deciding if the birds all belong to a single species?
Whether the matings produce viable eggs or offspring of some matings are sterile
Of the following, ________ can change local species diversity but not global species diversity.
immigration and extirpation
Of the following, ________ can change global species diversity.
speciation and extinction
Which regions of the world tend to have the greatest species richness?
regions near the equator
__________ provides the raw material for adaptation to local conditions
Genetic diversity
Species richness is the __________
number of species in an area
Biodiversity is the diversity of life at what level(s) of biological organization?
genetic, species, and ecosystem levels
Global biodiversity exists in a number of patterns. The largest and most obvious of these is that biodiversity is __________
greatest at the equator and drops as you move farther north or south
Why can many different species coexist and thrive in areas close to the equator?
Stable equatorial climatic conditions discourage any one species from dominating the ecosystem and encourage biodiversity
A species is a distinct type of organism, a set of individuals that uniquely share certain characteristics and can breed with one another and produce fertile offspring.
Extinction occurs when the last individual of a given species dies, and the species ceases to exist.
When a species disappears from an area it once occupied, but the species still exists elsewhere, this is called extirpation.
The number or variety of species in a given region is called species diversity.
Populations with very little genetic diversity are vulnerable to environmental change because they may lack the ability to adapt to different conditions.
Biodiversity is defined as the variety of life across all levels of biological organization.
Biodiversity enhances human food security because it ________
is a potential source of new food items or new genetic varieties of existing foods
Removal of ________ will always result in the greatest changes in an ecological system
a keystone species
Ecotourism ________
increases biodiversity by providing income to areas that might otherwise be destroyed
__________ is the gradual piecemeal degradation of an area by such activities as logging and road building
Habitat fragmentation
__________ is the term we use when a population disappears from a given area but not globally
Extirpation
If a conservation biologist wanted to try to stop the largest cause of species extinction, what should he or she focus on
habitat destruction
Which of the following is an example of the single greatest cause of species extinction?
habitat fragmentation caused by building a road through a forest
When a species declines in number, it also __________
occupies less area than it once did
Which of the following types of species would be most vulnerable to overharvesting by people?
whales
Recently, researchers surveyed the scientific literature, reviewing all research that compared the effects on biodiversity of organic farming versus conventional industrialized farming practices. The scientists predicted organic farming would benefit most organisms because of reduced chemical pollution. The graph shows the overall number of studies that showed positive effects (such as increases in abundance or species richness) and negative effects of organic farming on biodiversity.
Overall, how many studies showed a positive effect of organic farming on biodiversity?
66
What percentage of the studies showed a negative effect of organic farming on organisms?
11%
For which group of organisms is evidence of positive effects the strongest?
Plants
What is the overall ratio of positive effects of organic farming to negative effects?
8.25:1
A scientist plans to further investigate the impact of organic farming on biodiversity. Which groups of organisms should the scientist select?
Beetles and other arthropods
What percent of the plant species found on Madagascar are unique to that island?
80%
The human population of Madagascar doubles about every _____ years
25
What is a lemur?
a primate only found on Madagascar
Much of the original forest cover on Madagascar has been destroyed primarily as a result of _____.
burning for agricultural purposes
What is the cause of the red color of the waters about Madagascar?
soil that has washed into the ocean
The IUCN’s Red List is ________
an updated list of species facing unusually high risk of extinction
Paleontologists and ecologists agree that ________
99% of all species that have ever existed are now extinct
__________ provide(s) a benefit to humans free of charge
Ecosystem services
Which one of the following is an ecosystem service?
purification of water
The development of pharmaceutical products has been __________
aided by protection of ecosystem diversity
Pharmaceuticals produced from wild species generate up to $150 billion in sales and save many lives each year. This is an example of __________
ecosystem services
What is the second greatest cause of decline for threatened species?
Pollution
Which of these statements is supported by the graph? Select all that apply
Habitat loss is the greatest known cause of amphibian decline; The declines of many amphibian species are unexplained
Click here to complete this activity.
One of the most severe consequences of habitat degradation is the _____ of a population.
fragmentation
A sink habitat is where a subpopulation’s death rate is _____
greater than its reproductive rate
Fertilizer runoff can result in _____ a lake.
the eutrophication of
Most biodiversity hot spots are in the _____
tropics
_____ is the increase in pesticide concentration as the pesticides pass up a food chain
Biological magnification
According to island biogeography, what is the relationship between an island’s distance from the mainland and the number of species present on the island?
The farther an island is from the mainland, the fewer the number of species found on the island
Why is a new island more hospitable to colonizers than an older island is?
The intensity of both competition and predation is less on the newer island.
What is the relationship between colonizing success and the number of species already established on an island?
As the number of established species on an island increases, colonizing success decreases
The number of species on an island remains relatively constant when ____
the rate of successful colonization equals the extinction rate
More greenhouse gas emissions will indirectly lead to ________
loss of ecosystem services
Loss of aesthetic and spiritual ties with nature would be less if we ________
decreased the rate of habitat alteration and destruction
Changes in habitat have tremendous effects on the organisms that depend on them. These effects are ________
generally negative; organisms are already adapted to the habitats in which they occur and any change is likely to render the habitat less suitable
The greatest cause of the worldwide loss of species is ________
habitat destruction
What is the greatest contributing factor in the loss of polar bears in arctic areas?
Decline in sea ice
Wildlife in the Serengeti is currently threatened by ________
plans to build a highway that passes through the park
A species of lizard has gone extinct. This could be due to any of the following reasons except
increased genetic diversity within the species
In general, successfully introduced non-native species experience ________
competitive success against native species
Bullfrog tadpoles are often sold as fish bait, even in areas where they do not occur naturally. When people buy 10 of them and don’t use them all, they often dump the remainder into the lake or river. This is an example of ________
introduced species
The species most often vulnerable to human impact is the ________
top predator
A migratory bat species pollinates agave plants in northern Mexico on its way to the southwestern United States where it spends the summer eating insects and reproducing. Farmers spraying pesticides affect these bats, which eat the insects and also feed them to the baby bats. This could be the start of a story about ________
threats to a keystone species
European rabbits were introduced into Australia and quickly spread, reproduced, and became a terrible pest. They eat up to $600 million worth of food and pasture crops annually, and have damaged the populations of many native plants and the populations of animals that eat the plants. Twice in the past 50 years, rabbit diseases have been introduced to try to control the population, with some success. This is a case where ________
an invasive species has reduced the genetic diversity of indigenous species
The country of Belize depends on lobster for a major portion of its income, along with fishing and tourism. Over the past 30 years the average size of an individual lobster has dropped, even as increasing numbers of Belizeans buy boats, build lobster traps, and enter the industry. This is an example of ________
overharvesting
The wood thrush makes its nest in woodlands in the northern and eastern United States. As patches of woods become smaller, increasing numbers of wood thrush nests have eggs laid in them by the brown-headed cowbird. Cowbirds live in open fields and are nest parasites; the female cowbird flies up to an unattended nest, quickly lays an egg in another bird’s nest, and leaves the host parents to raise their “adopted” young. Wood thrushes are decreasing in numbers because ________
habitat fragmentation makes it easier for cowbird parasitism to occur
Many biologists and environmental educators are interested in maintaining biodiversity in urban landscapes, where preserves or reserves are scarce unless land has been set aside for them in urban planning. Nonetheless, they have discovered that making even small changes in commercial and residential landscaping can help promote biodiversity. Some of the changes that have been recommended and are having success are using native species for street trees and for decorative landscaping, reducing pesticide use on lawns and gardens and reducing fertilizer use through composting and mulching. Also, managers of schools, larger businesses and residences are encouraged to increase habitat diversity by creating “landscape islands” that include larger trees surrounded by shrubs and herbaceous plants. Landscape islands ideally should include native species, mixed with exotic ornamentals at the discretion of the land owners.
Being interested in native butterflies, you include the native caterpillar host plants of several butterflies in your annual landscape design. You are happy to see that caterpillars and butterflies appear in your yard. However, the butterflies tend to disperse out of our yard. To keep the butterflies in your garden, an urban wildlife specialist suggests you ________
introduce native flowering plants the adult butterflies need for nectar, their main food
In addition to the butterfly project, you decide to stop spraying the pesticides that control lawn pests. Over the next year, you notice that the lawn grass doesn’t grow as well, but many other species of plants invade the lawn, many of them native species. This will result in all of the following, except ________
lower survival rates for the caterpillars and butterflies
From your experiences with the lawn and the butterfly garden, you can affirm that ________
native plants are more likely to support local herbivorous animals than are exotic plant species
You also decide to greatly reduce the amount of chemical fertilizers you use in your landscape and rely more on mulching and composting. This will benefit your yard “ecosystem” by _______
reducing nutrient pollution in nearby areas and increasing soil organisms’ biodiversity
The primary legislation for protecting biodiversity in the United States is the __________
Endangered Species Act
Conservation biology is different from other fields of science discussed in the book because __________
it is an applied and goal-oriented science, with implicit values and ethical standards
How is community-based conservation different from more traditional approaches to conservation?
local people are involved with protecting the habitat of endangered species, allowing them to still gain benefit from its resources
Which of the following best describes an umbrella species
a species whose protection will result in the protection of a large number of species that require the same habitat
Which of the following statements about cloning organisms is true?
Producing cloned animals and keeping them in zoos does not increase biodiversity of the species
The researchers bought samples of whale meat—all labeled simply as kujira, the generic Japanese term for whale meat—from markets in Japan and sequenced DNA from these samples. They compared their data with sequences from known whale species. Because subspecies of whales from different populations differ genetically, the researchers were able to analyze the genetic variation in their samples and learn the location from which the whales were likely captured. These results would indicate if illegal whale meat was being sold.
As part of their study, Baker and his team examined minke whale (Balaenoptera acutorostrata) meat in Japanese markets. They sequenced each sample’s DNA and then identified the genetic type of each minke sample—in this case, type A, B, C, or D.
Because the genetic types of minke whales vary by location, the researchers could determine if the meat came from minke populations in the Sea of Japan or from minke populations in the Pacific Ocean. Their results, shown below, were compared to records of legal whale catches to determine if such catches had been underreported.
- Genetic type D is most prevalent in minke whales in the Sea of Japan.
- Genetic type B is most prevalent in minke whales in the Pacific Ocean.
- Genetic type B is most prevalent in meat from minke whales in Japanese markets.
- The high prevalence of genetic types A and D in whale meat from Japanese markets suggests some of these whales came from the Sea of Japan.
- The high prevalence of genetic type B in whale meat from Japanese markets suggests some of these whales came from the Pacific Ocean.
- Genetic type G is found only in Location 1.
- Genetic type D is most prevalent in humpback whales in Locations 1 and 3.
- Genetic type A is most prevalent in humpback whales in Location 2.
- Analysis of meat samples from Japanese markets finds that most of the whales were likely captured from Location 2.
- The meat samples from Japanese markets also showed evidence of whales captured from a second site, Location 1.
In the face of mounting international pressure to reduce captures of whales as bycatch, suppose the Japanese government ordered its fishing vessels off the coast of Japan (Location 1) to embrace new techniques and technologies aimed at reducing the bycatch of humpback whales. The fishing fleets in the waters off Hawaii and off the western coast of Central America (Locations 2 and 3) do not embrace these changes and fish as they always have.
Three years after the changes were implemented, the Japanese government reports significantly lower numbers of humpback whales being captured as bycatch in the waters off Japan (Location 1). But conservation biologists are skeptical. They ask you to analyze whale meat from Japanese markets and compare your findings to your previous results. You only test whale meat that is less than three years old to ensure you sample only whales captured since the conservation strategies were implemented.
Which of the following results from Japanese markets would indicate that the Japanese fishing vessels off the coast of Japan (Location 1) have indeed reduced bycatch of humpback whales? (Refer back to the map in Part C to review which genetic types are found in the humpback whale population in Location 1.)
Answer:
Since genetic type G is found only in whales off Japan (Location 1), a lower percentage of genetic type G in Japanese markets would indicate that fewer whales were being captured from Location 1 and therefore that the conservation strategy is working.
- Extinction The loss of species from the planet
- Genetic diversity Differences in DNA composition among individuals within a given species
- Speciation A population differentiating, over time, into a new species
- Umbrella species Protected animals, such as tigers, that need large amounts of land
- Biophilia The connections that human beings subconsciously seek with the rest of life
- Hotspot An area that supports an especially great diversity of endemic species