BISC 121 - Conservation Biology and Global Change Part 1 - Midterm 4

How many species have been named and described?

1.8 million species have been named and described

How many species do biologists estimate exist on Earth?

10–200 million species exist on Earth

Where are some of the greatest concentrations of species found?

Tropical forests contain some of the greatest concentrations of species

What is happening to tropical forests?

They are being destroyed at an alarming rate

What are humans doing to many species?

Humans are rapidly pushing many species toward extinction

Is the situation hopeless regarding species loss?

It is not hopeless

What can be done to degraded habitats?

Degraded habitats can be restored

Is there any positive progress?

There is some progress locally

What is conservation biology?

Conservation biology seeks to preserve life

Which fields does conservation biology integrate?

Ecology, Physiology, Molecular biology, Genetics, Evolutionary biology

What example of environmental destruction is given?

Deforestation in Indonesia, where tropical forest is often converted into palm oil plantations

Rates of species extinction are difficult to determine under what conditions?

Under natural conditions

What is the high rate of species extinction largely a result of?

Ecosystem degradation by humans

How much higher is the current human-caused extinction rate than the background rate?

100–1000 times the “background” rate

What are humans threatening?

Earth’s biodiversity

What are the three main components of biodiversity?

Genetic diversity, Species diversity, Ecosystem diversity

What does genetic diversity comprise?

Genetic variation within a population and between populations

What is species diversity?

The variety of species in an ecosystem or throughout the biosphere

According to the U.S. Endangered Species Act, what is an endangered species?

“In danger of becoming extinct throughout all or a significant portion of its range”

According to the U.S. Endangered Species Act, what is a threatened species?

Likely to become endangered in the foreseeable future

What percentage of known fish species have become extinct or seriously threatened?

30%

How many North American freshwater animals have become extinct since 1900?

At least 123

How does the extinction rate of freshwater fauna compare to terrestrial fauna?

5X higher than terrestrial fauna

Why are conservation biologists concerned about species loss?

Because of alarming statistics regarding extinction and biodiversity

What percentage of birds are threatened with extinction globally?

Approx. 12%

What percentage of mammals are threatened with extinction globally?

20%

What percentage of amphibians are threatened with extinction globally?

32%

What do several researchers estimate about species loss by the end of this century?

Over half of all plant and animal species will be gone

Can extinction be local?

Yes

Can extinction also be global?

Yes

What is human activity reducing in terms of biodiversity?

Ecosystem diversity, the variety of ecosystems in the biosphere

What percentage of wetlands in the contiguous United States have been drained and converted?

More than 60%

What are wetlands often converted into?

Housing developments, shopping centers, or parking lots

What does human biophilia allow us to recognize?

The value of biodiversity for its own sake

What do many cite regarding stewardship of nature?

Moral and religious values and imperatives for humans to be good stewards of nature

What example is given of a stewardship story?

Noah’s Ark – the original Endangered Species Act

What additional benefit does species diversity bring humans?

Many practical benefits

What percentage of U.S. prescriptions contain substances originally derived from plants?

25%

What plant contains alkaloids that inhibit cancer growth?

The rosy periwinkle from Madagascar

What does loss of species also mean?

Loss of genes and genetic diversity

Why is enormous genetic diversity needed?

To allow ecosystems to adapt to a changing world

What potential does genetic diversity also have?

Potential for great human benefit

What do ecosystem services encompass?

All the processes through which natural ecosystems and their species help sustain human life

How do most people treat ecosystem services?

Most are taken completely for granted and their existence is not even recognized by most of us

What was Biosphere II attempting to create?

A closed ecosystem

How long were eight people supposed to be isolated in Biosphere II?

Two years

How long did the experiment last before being stopped?

15 months

What happened inside Biosphere II?

Oxygen dropped to 65% of normal, many species died, pests like cockroaches proliferated

What did the Biosphere II experiment show?

We simply did not know enough about the ecosystems to sustain them

What do ecosystem services include? (13)

Purification of air and water, Reduction of drought/flood severity, Generation & preservation of fertile soils, Detoxification and decomposition of wastes, Pollination of crops and natural vegetation, Dispersal of seeds, Nutrient cycling (including oxygen regeneration), Control of agricultural pests by natural enemies, Protection of shores from erosion, Protection from UV rays, Moderation of weather extremes, Provision of aesthetic beauty & recreation opportunities

How much have ecosystem services been estimated to be worth per year?

$33 Trillion per year

How does this compare to the gross national product of all countries combined?

Twice as much

Do governments typically consider the cost of losing ecosystem services when planning major projects?

Rarely if ever

What are examples of such projects?

Coastal development, dams, forest harvests, mines, petroleum extraction, recreational land use, military training exercises, energy planning, fossil fuel use

What is an example of ecosystem service loss worsening a disaster?

Loss of mangrove “islands” downriver of New Orleans leading to more damage by Hurricane Katrina

In official cost–benefit analyses, how are ecosystem services treated?

Usually ignored

Why are they ignored?

Frequently due to lobbying efforts by those being regulated

Under which administration were environmental and health costs removed from most official calculations?

The Trump Administration

What major issue would be greatly affected if such services were considered?

Climate change

What topic discusses these external costs?

Journal club

What are the three major threats most species loss can be traced to?

Habitat destruction, Introduced species, Overexploitation

What is the greatest threat to biodiversity throughout the biosphere?

Human alteration of habitat

What does habitat fragmentation and destruction lead to?

Loss of biodiversity

In Wisconsin, how much prairie remains compared to the original area?

<0.1% of the original area

What percentage of coral reefs have been damaged by human activities?

About 93%

What are introduced species?

Species that humans move from native locations to new geographic regions

Why may introduced species spread rapidly?

Without their native predators, parasites, and pathogens

Why do introduced species disrupt adopted communities?

Because they fill their fundamental niche due to lack of biological controls restricting them to a realized niche

How do introduced species often spread?

Humans introduce species by accident

What example is given of an accidental introduction?

The brown tree snake arriving in Guam as a cargo ship “stowaway”

What did the brown tree snake do?

Wiped out many native birds

What are examples of deliberate introductions with disastrous effects?

Kudzu in the southern U.S.; Mongoose in Hawaii

What did kudzu do?

Grows way out of control

Why was the mongoose introduced in Hawaii?

To control accidentally-introduced rats and snakes

What else does the mongoose kill?

Native birds like the nene

What is overharvesting?

Human harvesting of wild plants or animals at rates exceeding the ability of populations to rebound

How has the fishing industry contributed to overharvesting?

Greatly reduced populations of the large majority of harvested fish

What is an example of a threatened overharvested fish?

Bluefin tuna

What is an example of a collapsed fishery?

Georges Bank cod

What books are recommended on this subject?

“The Unnatural History of the Sea” and “The Ocean of Life” by Callum Roberts

What should you think about when choosing fish or sushi?

That overharvesting endangers species such as bluefin (“toro”)

Where can recommendations be found for sustainable seafood?

http://www.seafoodwatch.org/seafood-recommendations

What can DNA analysis help conservation biologists do?

Identify the source of illegally obtained animal products

What are examples of illegal products identified using DNA?

Whalemeat in Japan, abalone, ivory, and others

What did testing of Japanese whalemeat samples reveal?

Some samples came from endangered species, including humpback and blue whales

Where were whalemeat DNA samples tested?

In a Tokyo hotel room by Dr. C. Scott Baker

Why can Japanese whalers legally take fin whales?

For “research” and to sell the meat

Biologists focusing on what levels follow two main approaches?

Conservation at the population and species levels

What are the two main approaches in population-level conservation?

The small-population approach and the declining-population approach

What does the small-population approach study?

Processes that can make small populations become extinct

What is an extinction vortex?

A positive-feedback loop that draws a small population down toward extinction

What is the key factor driving the extinction vortex?

Loss of the genetic variation necessary to enable evolutionary responses to environmental change

What happened to greater prairie chicken populations?

They were fragmented by agriculture and later found to exhibit decreased fertility

What did scientists do to test the extinction vortex hypothesis?

Imported genetic variation by transplanting birds from larger populations

What happened after translocation of birds?

The declining population rebounded

What did this rebound confirm?

That low genetic variation had been causing an extinction vortex

What is minimum viable population (MVP)?

The minimum population size at which a species can survive

What determines MVP?

Factors that affect a population’s chances for survival over a particular time

What is needed to make a meaningful estimate of MVP?

Determining the effective population size

What is effective population size based on?

The population’s breeding potential