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Biodiversity. Variety of the earth’s species, the genes they contain, the ecosystems in which they live, and the ecosystem processes such as energy flow and nutrient cycling that sustain all life. Hot Spots. A hotspot is an area where there are many threatened and endangered species

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Variety of the earth’s species, the genes they contain, the ecosystems in which they live, and the ecosystem processes such as energy flow and nutrient cycling that sustain all life.

hot spots
Hot Spots
  • A hotspot is an area where there are many threatened and endangered species
  • There are currently 34hotspots in the world today
species diversity
Species Diversity
  • Number and abundance of species present in different communities
ecological diversity
Ecological Diversity
  • The variety of terrestrial and aquatic ecosystems found in an area or on the earth
functional diversity
Functional Diversity
  • The biological and chemical processes such as energy flow and matter recycling needed for the survival of species, communities and ecosystems
    • Food Chains & webs
genetic diversity
Genetic Diversity
  • The variety of genetic material within a species or a population
theory of natural selection
Theory of Natural Selection
  • Explains how life has evolved from a common ancestor
survival of the fittest
Survival of the fittest
  • Organisms suited for the environment will survive to reproduce, thus passing down desirable traits.
    • Examples:
      • Giraffes
      • Camels
      • Influenza virus
      • Venus fly trap
  • NOTE – fittest does not equal strongest!!!
natural selection and geological processes
Natural Selection and Geological Processes
  • Location on the earth influences biodiversity (rainforest vs. tundra)
  • Continental movement
    • Earthquakes and volcanoes
  • Climate change
    • Cyclic cooling and heating of the earth
  • Catastrophic events
    • Asteroid impacts, major volcanic eruptions
continental movement
Continental movement
  • Theory of Continental Drift
  • The earth has large plates located between the lithosphere and asthenosphere
  • These plates move very slowly (1-3cm/yr)
  • This creates oceans, mountain ranges, volcanoes, earthquakes, trenches
225 million years ago
225 million years ago

225 million years ago

135 million years ago

65 million years ago


Fig. 4-5, p. 88

climate change and natural selection
Climate Change and Natural Selection
  • Changes in climate throughout the earth’s history have shifted where plants and animals can live.

Figure 4-6

catastrophic events
Catastrophic events
  • Asteroid impacts
  • Super Volcanoes
  • These affect biodiversity locally and on a world-wide scale
speciation formation of a new species
Speciation - formation of a new species
  • Two Phases
    • 1. Geographic isolation
      • A population is removed from others of it’s species for a long period of time
    • 2. Reproductive isolation
      • The removed population becomes so genetically different over time that it can no longer interbreed with others of it’s species
measurements of biodiversity
Measurements of Biodiversity
  • Species diversity – the number of different species in a community
  • Species evenness – the abundance of species in a community
richness and sustainability
Richness and Sustainability
  • Higher species richness = higher productivity = higher sustainability
  • Reasons:
    • More likely to withstand droughts, disease, climate change, nutrient shortages
    • Higher number of producers lead to a higher biomass which leads to more carbon and nitrogen cycling
extinction the loss of a species
Extinction – the loss of a species
  • Background extinction – low rate of extinctions
  • Mass extinction-high rate of extinctions due to specific cause
    • Climate change
three types of extinctions
Three types of extinctions
  • Local: A species is no longer found in an area it once inhabited but is still found elsewhere in the world.
  • Ecological: Occurs when so few members of a species are left they no longer play its ecological role.
  • Global (biological): Species is no longer found on the earth.
global extinction
Global Extinction
  • Some animals have become prematurely extinct because of human activities.

Figure 11-2

steps to extinction
Steps to extinction

Background extinctions:

  • Rare
  • Threatened
  • Endangered
  • Extinct
endangered and threatened species ecological smoke alarms
Endangered and Threatened Species: Ecological Smoke Alarms
  • Endangered species: so few individual survivors that it could soon become extinct.
  • Threatened species: still abundant in its natural range but is likely to become endangered in the near future.

Figure 11-3

red lists
Red lists
  • ICUN – International Union for the Conservation of Nature and Natural Resources
  • Published list of threatened species
  • www.
some species are more prone to extinction
Some species are more prone to extinction:
  • K-strategists
  • Specialists
  • Tertiary consumers
  • Fixed migratory patterns
  • Narrow distribution
  • Commercially valuable
  • Large territories

Florida manatee

Kirkland’s warbler

Grizzly bear

Knowlton cactus

African elephant

Swallowtail butterfly

Humpback chub

Utah prairie dog

Siberian tiger

Golden lion tamarin

Fig. 11-3, p. 224


Giant panda

Blue whale

Whooping crane

Northern spotted owl

Black-footed ferret

Mountain gorilla

Florida panther

California condor

Hawksbill sea turtle

Black rhinoceros

Fig. 11-3, p. 224


Indian Tiger

Range 100 years ago

Range today

(about 2,300 left)

Fig. 11-8a, p. 230


Black Rhino

Range in 1700

Range today

(about 3,600 left)

Fig. 11-8b, p. 230


African Elephant

Probable range 1600

Range today

Fig. 11-8c, p. 230


Asian or Indian Elephant

Former range

Range today

(34,000–54,000 left)

Fig. 11-8d, p. 230

extinction rate
Extinction Rate
  • The percentage of species that go extinct within a certain time period
  • The current extinction rate is increasing at an alarming rate due to human activities
history of extinctions

Endangered Species

History of Extinctions
  • Extinctions have existed long before humans had an influence
  • The current extinction crisis is the first to be caused by a single species- US! . This is happening faster than ever; a few decades versus thousands to millions of years.
  • Humans are eliminating not only the species but, the environment. Ex. Tropical rainforest
effects of humans on biodiversity
Effects of Humans on Biodiversity
  • The scientific consensus is that human activities are decreasing the earth’s biodiversity.

Figure 4-13

human caused extinction
Human Caused Extinction
  • Causes include:
    • Habitat Destruction
    • Invasive species
    • Population Growth
    • Pollution
    • Over-harvesting
    • Climate Change

Species and families


mass extinction

Bar width represents relative

number of living species

Millions of

years ago




Current extinction crisis caused

by human activities. Many species

are expected to become extinct

within the next 50–100 years.







Cretaceous: up to 80% of ruling

reptiles (dinosaurs); many marine

species including many

foraminiferans and mollusks.





Triassic: 35% of animal families, including many reptiles and marine mollusks.




Permian: 90% of animal families, including over 95% of marine species; many trees, amphibians, most bryozoans and brachiopods, all trilobites.






Devonian: 30% of animal families, including agnathan and placoderm fishes and many trilobites.







Ordovician: 50% of animal families, including many trilobites.


Fig. 4-12, p. 93

natural extinctions
Natural Extinctions
  • Causes include
    • Climate change
    • Change in ecosystem
    • Lack of adaptations to change
how do extinctions affect us
How do extinctions affect us?
  • Use value lost – medicinal use, recreation, crops, lumber
  • Economic value – ecotourism (African safari)
  • Genetic information – genetic diversity lost
  • Non-use values – appreciation
case study the u s endangered species act
Case Study: The U.S. Endangered Species Act
  • Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S.

Figure 11-18