2. This lecture will help you understand:
The scope of Earth’s biodiversity
Background rates and mass extinction
Primary causes of biodiversity loss
The benefits of biodiversity
Conservation biology
Biodiversity conservation efforts

3. Central Case: Saving the Siberian tiger
The largest cat in the world
The Russian Far East mountains house the last remaining tigers
Nearly became extinct due to hunting, poaching and habitat destruction
International conservation groups saved the species from extinction
Research, education, zoos, and captive breeding programs

4. Biodiversity encompasses several levels
Humans are reducing Earth’s diversity of life
Biodiversity – sum total of all organisms in an area
Split into three specific levels:
Species diversity
Genetic diversity
Ecosystem diversity

5. Species diversity
Species Diversity = the number or variety of species in the world or in a particular region
Richness = the number of species
Evenness or relative abundance = extent to which numbers of individuals of different species are equal or skewed
Speciation generates new species and adds to species richness
Extinction reduces species richness

6. The taxonomy of species
Taxonomists = scientists who classify species
Physical appearance and genetics determines a species
Genera = related species are grouped together
Families = groups of genera
Every species has a two-part scientific name: genus and species

7. Subspecies: the level below a species
Subspecies = populations of species that occur in different areas and differ slightly from each other
Divergence stops short of separating the species
Subspecies are denoted with a third part of the scientific name
Siberian tiger = Panthera tigris altaica
Bengal tiger = Panthera tigris tigris

8. Genetic diversity
Encompasses the differences in DNA among individuals within species and populations
The raw material for adaptation to local conditions
Populations with higher genetic diversity can survive
They can cope with environmental change
Populations with low genetic diversity are vulnerable
To environmental change
Disease
Inbreeding depression = genetically similar parents mate and produce inferior offspring

9. Ecosystem diversity
Ecosystem diversity = the number and variety of ecosystems
Also encompasses differing communities and habitats
Rapid vegetation change and varying landscapes within an ecosystem promote higher levels of biodiversity

10. Some groups contain more species than others
Species are not evenly distributed among taxonomic groups
Insects predominate over all other life-forms
40% of all insects are beetles
Groups accumulate species by
Adaptive radiation
Allopatric speciation
Low rates of extinction

11. Insects outnumber all other species

12. Measuring biodiversity is not easy
Out of the estimated million species on Earth, only million species have been successfully catalogued
Very difficult to identify species
Many remote spots on Earth remain unexplored
Small organisms are easily overlooked
Many species look identical until thoroughly examined
Entomologist Terry Erwin found 163 beetle species specialized on one tree species

13. Biodiversity is unevenly distributed
Living things are distributed unevenly across Earth
Latitudinal gradient = species richness increases towards the equator
Canada has species of breeding birds, while Costa Rica has more than 600 species

14. Latitudinal gradient has many causes
Climate stability, high plant productivity, and no glaciation
Tropical biomes support more species and show more species evenness
Diverse habitats increase species diversity
Human disturbance can increase habitat diversity
But only at the local level

15. Biodiversity losses and species extinction
Extinction = occurs when the last member of a species dies and the species ceases to exist
Extirpation = the disappearance of a particular population from a given area, but not the entire species globally
Can lead to extinction

16. Extinction is a natural process
Paleontologists estimate 99% of all species that ever lived are now extinct
Background rate of extinction = natural extinctions for a variety of reasons
1 extinction per 1 to 10 million species for mammals and marine species
1 species out of 1,000 mammal and marine species would go extinct every 1,000 to 10,000 years

17. Earth has experienced five mass extinctions
In the past 440 million years, mass extinctions have eliminated at least 50% of all species
After every mass extinction the biodiversity returned to or exceeded its original state

18. The current mass extinction is human caused
During this Quaternary period, we may lose more than half of all species
Hundreds of human-induced species extinctions, and multitudes of others, teeter on the brink of extinction
The current global extinction rate is 100 to 1,000 times greater than the background rate
This rate will increase tenfold in future decades due to human population growth and resource consumption

19. People have hunted species to extinction for millennia
Extinctions followed human arrival on islands and continents

20. Current extinction rates are higher than normal
The Red List = an updated list of species facing high risks of extinctions
23% of mammal species
12% of bird species
% of all other species
Since 1970, 58 fish species, 9 bird species, and 1 mammal species has gone extinct
In the U.S., in the last 500 years, 236 animal and 17 plant species are confirmed extinct
Actual numbers are undoubtedly higher

21. Biodiversity loss is more than extinction
Decreasing numbers are accompanied by smaller species’ geographic ranges
Genetic, ecosystem, and species diversity are being lost.
The Living Planet Index summarizes trends in populations
Between 1970 and 2003, the Index fell by 30%

22. Biodiversity loss has many causes
Reasons for biodiversity losses are multifaceted, complex, and hard to determine
Factors may interact synergistically
Four primary causes of population decline are:
Habitat alteration
Invasive species
Pollution
Overharvesting
Global climate change now is the fifth cause

23. Habitat alteration causes biodiversity loss
The greatest cause of biodiversity loss
Farming simplifies communities
Grazing modifies the grassland structure and species composition
Clearing forests removes resources organisms need
Hydroelectric dams turn rivers into reservoirs upstream
Urbanization and suburban sprawl reduce natural communities
A few species (i.e., pigeons, rats) benefit from changing habitats

24. Habitat alteration has occurred in every biome
Particularly in tropical rainforests, savannas, and tropical dry forests

25. Invasive species cause biodiversity loss
Introduction of non-native species to new environments
Accidental: zebra mussels
Deliberate: food crops
Island species are especially vulnerable
Invaders have no natural predators, competitors, or parasites
Cost billions of dollars in economic damage

26. Pollution causes biodiversity loss
Harms organisms in many ways
Air pollution degrades forest ecosystems
Water pollution adversely affects fish and amphibians
Agricultural runoff harms terrestrial and aquatic species
The effects of oil and chemical spills on wildlife are dramatic and well known
The damage to wildlife and ecosystems caused by pollution can be severe
But it tends to be less than the damage caused by habitat alteration or invasive species

27. Overharvesting causes biodiversity loss
Vulnerable species are large, few in number, long-lived, and have few young (K-selected species)
The Siberian tiger is hunted without rules and regulations
The early 1990s saw increased poaching because of powerful economic incentives
Many other species affected: Atlantic gray whale, sharks, gorillas
Today the oceans contain only 10% of the large animals they once did

28. Climate change causes biodiversity loss
Emissions of greenhouse gases warms temperatures
Modifies global weather patterns and increases the frequency of extreme weather events
Increases stress on populations and forces organisms to shift their geographic ranges
Most animals and plants will not be able to cope

29. Warming has been the greatest in the Arctic
The polar bear is being considered for the endangered species list

30. Biodiversity loss has a variety of causes

31. Biodiversity provides free ecosystem services
Provides food, shelter, fuel
Purifies air and water, and detoxifies wastes
Stabilizes climate, moderates floods, droughts, wind, temperature
Generates and renews soil fertility and cycles nutrients
Pollinates plants and controls pests and disease
Maintains genetic resources
Provides cultural and aesthetic benefits
Allows us to adapt to change
The annual value of just 17 ecosystem services = $ trillion per year

32. Biodiversity helps maintain ecosystem function
Biodiversity increases the stability and resilience of communities and ecosystems
Decreased biodiversity reduces a natural system’s ability to function and provide services to our society
The loss of a species affects ecosystems differently
If the species can be functionally replaced by others, it may make little difference
Extinction of a keystone species may cause other species to decline or disappear
“To keep every cog and wheel is the first precaution of intelligent tinkering” (Aldo Leopold)

33. Biodiversity enhances food security
Genetic diversity within crops is enormously valuable
Turkey’s wheat crops received $50 billion worth of disease resistance from wild wheat
Wild strains provide disease resistance and have the ability to grow back year after year without being replanted
New potential food crops are waiting to be used
Serendipity berry produces a sweetener 3,000 times sweeter than sugar

34. Some potential new food sources

35. Organisms provide drugs and medicines
Each year pharmaceutical products owing their origin to wild species generate up to $150 billion in sales
The rosy periwinkle produces compounds that treat Hodgkin's disease and leukemia

36. Biodiversity generates economic benefits
People like to experience protected natural areas, creating economic opportunities for residents, particularly in developing countries
Costa Rica: rainforests
Australia: Great Barrier Reef
Belize: reefs, caves, and rainforests
A powerful incentive to preserve natural areas and reduce impacts on the landscape and on native species
But, too many visitors to natural areas can degrade the outdoor experience and disturb wildlife

37. People value and seek out nature
Biophilia = connections that humans subconsciously seek with life
Our affinity for parks and wildlife
Keeping of pets
High value of real estate with views of natural lands
Nature deficit disorder = alienation from the natural environment
May be behind the emotional and physical problems of the young

38. Do we have ethical obligations to other species?
Humans are part of nature and need resources to survive
But, we also have conscious reasoning ability and can control our actions
Our ethics have developed from our intelligence and our ability to make choices
Many people feel that other organisms have intrinsic value and an inherent right to exist

39. Conservation biology responds to biodiversity loss
Conservation biology = devoted to understanding the factors that influence the loss, protection, and restoration of biodiversity
Arose as scientists became alarmed at the degradation of natural systems
An applied and goal-oriented science

40. Conservation scientists work at multiple levels
Conservation biologists integrate evolution and extinction with ecology and environmental systems
Design, test, and implement ways to mitigate human impacts
Conservation geneticists = study genetic attributes of organisms to infer the status of their population
Minimum viable population = how small a population can become before it runs into problems
Metapopulations = a network of subpopulations
Small populations are most vulnerable to extinction and need special attention

41. Island biogeography
Equilibrium theory of island biogeography = explains how species come to be distributed among oceanic islands
Also applies to “habitat islands” – patches of one habitat type isolated within a “sea” of others
Explains how the number of species on an island results from an equilibrium between immigration and extirpation
Predicts an island’s species richness based on the island’s size and distance from the mainland

42. Species richness results from island size and distance
Fewer species colonize an island far from the mainland
Large islands have higher immigration rates
Large islands have lower extinction rates

43. The species-area curve
Large islands contain more species than small islands
They are easier to find and have lower extinction rates
They possess more habitats

44. Small “islands” of forest rapidly lose species
Forests are fragmented by roads and logging
Small forest fragments lose diversity fastest
Starting with large species
Fragmentation is one of the prime threats to biodiversity

45. Should conservation focus on endangered species?
Endangered Species Act (1973) (ESA) = forbids the government and private citizens from taking actions that destroy endangered species or their habitats
To prevent extinction
Stabilize declining populations
Enable populations to recover
As of 2007, the U.S. had 1,312 species listed as endangered or threatened

46. Despite opposition, the ESA has had successes
Peregrine falcons, brown pelicans, bald eagles, and others have recovered and are no longer listed
Intensive management has stabilized other species
The red-cockaded woodpecker
40% of declining populations are now stable
These successes occur despite underfunding of the U.S. Fish and Wildlife Service and the National Marine Fisheries Service
In recent years, political forces have attempted to weaken the ESA

47. The ESA is controversial
Many Americans support protection of endangered species
Opponents feel that the ESA values endangered organisms more than the livelihood of people
Private land use will be restricted if an endangered species is present
“Shoot, shovel, and shut up” = landowners conceal the presence of endangered species on their land
But, the ESA has stopped few development projects
Habitat conservation plans and safe harbor agreements = landowners can harm species if they improve habitat for the species in other places 47

48. Other countries have their own version of the ESA
Species at Risk Act (2002) = Canada’s endangered species law
Stresses cooperation between landowners and provincial governments
Criticized as being too weak
Other nations’ laws are not enforced
The Wildlife Conservation Society has to help pay for Russians to enforce their own anti-poaching laws

49. Protecting biodiversity
Captive breeding – individuals are bred and raised with the intent of reintroducing them into the wild
Zoos and botanical gardens
Some reintroductions are controversial
Ranchers opposed the reintroduction of wolves to Yellowstone National Park
Some habitat is so fragmented, a species cannot survive 49

50. Protecting biodiversity
Cloning – a technique to create more individuals and save species from extinction
Most biologists agree that these efforts are not adequate to recreate the lost biodiversity
Ample habitat and protection in the wild are needed to save species

51. Umbrella species
Conservation biologists use particular species as tools to conserve communities and ecosystems
Protecting the habitat of these umbrella species helps protect less-charismatic animals that would not have generated public interest
Flagship species – large and charismatic species used as spearheads for biodiversity conservation
The World Wildlife Fund’s panda bear
Some organizations are moving beyond the single species approach to focus on whole landscapes 51

52. International conservation efforts
UN Convention on International Trade in Endangered Species of Wild Fauna and Flora (1973) (CITES) – protects endangered species by banning international transport of their body parts
Convention on Biological Diversity (1992) –
Seeks to conserve biodiversity
Use biodiversity in a sustainable manner
Ensure the fair distribution of biodiversity’s benefits
By 2007, 188 nations had signed on
Iraq, Somalia, the Vatican, and the U.S. did not join 52

53. Biodiversity hotspots
Biodiversity hotspots – prioritizes regions most important globally for biodiversity
Support a great number of endemic species = species found nowhere else in the world
The area must have at least endemic plant species (0.5% of the world total)
It must have lost 70% of its habitat due to human impact 53

54. There are 34 global biodiversity hotspots
2.3% of the planet’s land surface contains 50% of the world’s plant species and 42% of all terrestrial vertebrate species

55. Community- based conservation
Protecting habitats makes good sense, but this affects people living in and near these areas
Community-based conservation = conservation biologists actively engage local people in protecting land and wildlife
Protecting land deprives people access to resources
But, it can guarantee that these resources will not be used up or sold to foreign corporations and can instead be sustainably managed
Many projects have succeeded
But, others have not, due mainly to funding problems 55

56. Innovative economic strategies
Debt-for-nature swap = a conservation organization pays off a portion of a developing country’s international debt
In exchange for a promise by the country to set aside reserves
Fund environmental education, and
Better manage protected areas
Conservation concession = conservation organizations pay nations to conserve, and not sell, resources 56

57. Conclusion Loss of biodiversity will result in a mass extinction
Primary causes of biodiversity loss are:
Habitat alteration, invasive species, pollution, overharvesting of biotic resources, and climate change
Human society cannot function without biodiversity’s benefits
Science can help save species, preserve habitats, restore populations, and keep natural ecosystems intact 57

58. QUESTION: Review
Which level is NOT included in the concept of biodiversity?
Species
Genetics
Ecosystems
All of the above are included in this concept
Answer: d

59. QUESTION: Review
What happens when a species experiences “inbreeding depression”?
The species becomes too large for the resource base
Genetically similar parents mate and produce inferior offspring
Genetically similar parents mate and produce superior offspring
The number and variety of species increases
Answer: b

60. QUESTION: Review Species richness increases towards the equator
According to the concept of “latitudinal gradient,” which of the following happens?
Species richness increases towards the equator
Species richness decreases towards the equator
Species richness decreases over time
Countries like Canada have many more species than expected
Answer: a

61. QUESTION: Review
Which of the following is the major cause of extinction?
Invasive species
Pollution
Habitat loss
Overharvesting
Answer: c

62. QUESTION: Review Biodiversity does all of the following, except…
Provide ecosystem services
Decrease food security
Maintain ecosystem function
Provide aesthetic benefits
Answer: b

63. QUESTION: Review
According to the theory of island biogeography, which island would have the highest species richness?
A large island, close to the mainland
A large island, far from the mainland
A small island, close to the mainland
A small island, far from the mainland
Answer: a

64. QUESTION: Review A “biodiversity hotspot” is…?
An area located near the equator
An area that supports few, but large, species
An area that contains naturally high numbers of people
An area that contains a large number of endemic species
Answer: d

65. QUESTION: Weighing the Issues
If a pharmaceutical company produces a medicine from a plant found in Costa Rica that will earn millions of dollars, who should reap the financial benefits?
The company, because it produced the drug
Costa Rica, because it had the plant that produced the drug
Taxpayers, because they fund lots of research through their tax dollars
Both the company and Costa Rica, because both played a vital part
Answer: any

66. QUESTION: Weighing the Issues
Have you ever personally experienced evidence of the biophilia hypothesis?
Yes, I frequently feel a connection to other living things and nature
Yes, sometimes, on a particularly lovely day
Maybe, but I’m not sure
Definitely not, unless I was earning money from using nature
Answer: any

67. QUESTION: Interpreting Graphs and Data
Where would ecotourists go to view the maximum species richness on these islands?
a) Redonda
b) Montserrat
c) Puerto Rico
d) Hispaniola
Answer: d

68. QUESTION: Interpreting Graphs and Data
Which biome lost the most area by 1950; which biome lost the most area in recent decades?
Temperate grassland; tropical dry forest
Desert; savanna
Chaparral; tundra
Temperate grassland; desert
Answer: a