Biodiversity, Endangered Species, and Extinction

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Biodiversity, Endangered Species, and Extinction

• APES
• October 2004

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What is a species and how many are there?

• A species is a group of organisms that resemble
  one another in appearance, behavior, chemistry,
  and genetic make-up
• The true test to determine if two individuals are
  members of the same species is to see whether or
  not viable (fertile) offspring can be produced
  under natural conditions
• We dont know how many exist on earth
• 1.5 to 1.8 million identified
• Estimates (save bacteria) are 3 to 100 million
• Most common are insects and plants

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What is biodiversity

• A renewable resource
• The different forms of life and life sustaining
  processes that can best survive the variety of
  habitats on earth
• Four different types fall under biodiversity
• Genetic Diversity
• Species Diversity
• Ecological Diversity
• Functional Diversity

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Why is biodiversity important?

• The rich variety of genes, species, biological
  communities, and life sustaining processes
• Give us wood, fibers, energy, raw materials,
  industrial chemicals, medicines etc that fuel our
  economies (estimated _at_ 37 trillion/yr)
• Purify our water, air, soil
• Decompose our organic and chemical wastes
  recycle nutrients
• Natural pest control and pollination
• Regulate climate, protect us from harmful
  radiation
• Production of all food
• Prevent soil erosion/flood control
• Detoxification of human and industrial wastes

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Who cares!? Its just one species!

• Every species today contains genetic information
  that represents millions of years of evolution
  and adaptation to earths changing environmental
  conditions
• This diversity also represents the raw materials
  for future adaptations if environmental
  conditions change
• In other words, biodiversity is lifes insurance
  policy against natural disaster!
• Loss of biodiversity
• Reduces the availability of ecosystem services
• Decreases ability of species and ecosystems to
  adapt to changing environmental conditions

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BiodiversitySpeciation minus extinction

• When environmental conditions change, a species
  must either
• Evolve (become better adapted) OR
• Move to a more favorable environment OR
• Cease to exist (become extinct)
• Extinction is the ultimate fate of all species
  just as death is ultimate fate of all individuals
• 99.9 of all of the species that have ever
  existed are now extinct!
• Background Rate vs. Mass Extinctions

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Extinctions over time
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Are humans currently causing a mass extinction?

• During 20th century, it has been estimated that
  the extinction rate has increased 100 to 1000
  times the natural background rate
• We already use 27 of earths NPP
• 75 of habitable area disturbed
• World wide forest cover reduced by 20-50
• More than half of wetlands of the world
  threatened
• On our time scale, the loss of these species
  cannot be recouped by formation of new species
  (b/c this takes a long time)
• Genetic engineering wont solve this (why?)

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Human Impacts on Extinction Rates

• Before humans, estimated rate was one species per
  million ( 0.0001 per yr)
• Now, best guess is 0.1 per yr (1000X background
  rate)
• If the rate is as high as 1 as some believe
  (E.O. Wilson), then 20 of current animal and
  plant species could be gone by 2030 and 50 gone
  by the end of this century
• At this rate, it will take at least 5 million
  years for speciation to rebuild the diversity we
  destroy during this century.

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Premature Extinctions Caused By Human Beings
Nature Conservancy Study 539 extinctions since
1600
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Underlying Causes of Extinction
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Human Impacts on Ecosystems

• Fragmenting and degrading habitat (stop)
• e.g. Tropical forests being cut at a rate of 0.6
  to 2 per year
• Half of remaining forests lost or degraded in 25
  to 83yrs
• Simplifying natural ecosystems
• Creating monocultures
• Using, wasting, or destroying an increasing
  percentage of earths NPP (27 of total)
• Strengthening some populations of pest species
  and disease causing bacteria by causing genetic
  resistance through overuse of pesticides
  antibiotics
• Eliminating some key predators
• Deliberately or accidentally introducing exotic
  species
• Over harvesting of renewable resources
• Interfering with normal cycling and flows of
  energy in ecosystems

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Habitat Loss
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Poaching often Extinction
CITIES Treaty
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Endangered vs. Threatened

• Endangered
• So few left that species could soon become
  extinct over all or most of its range
• Threatened
• Still relatively abundant but b/c of declining
  numbers is likely to become endangered in the
  near future
• WWF study 30k Under threat of extinction
• 34 of worlds fish
• 25 of worlds amphibians
• 24 of worlds mammals
• 20 of worlds reptiles
• 14 of worlds plant species
• 12 of worlds bird species

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Endangered and Threatened Part I
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Endangered and Threatened Part II
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Endangered and Threatened Part III
320
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What makes a species vulnerable to extinction?

• Specialized niche
• Low reproductive rate
• Blue whales, giant panda, rhinoceros
• Feeds at high trophic level
• Bengal tiger, bald eagle
• Fixed migratory patterns
• Blue whale, whooping crane, sea turtles
• Commercially valuable
• Snow leopard, tigers, elephants, rare birds,
  orchids
• Rare/Narrow Distribution (island species)
• Need Large Territory
• Condor, Florida panther

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Types of Extinctions

• Local
• No longer in an area it once inhabited
• Ecological
• So few left that it cant do its job
• Biological
• No longer found anywhere on earth

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Status of Biodiversity
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Hot Spots of Biodiversity in the USA
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Why preserve wild species?

• Economic goods
• Food, fuel, lumber, fiber, paper, etc
• 40 of all medicines and 80 of top 150
  prescription drugs in USA derived from living
  organisms
• Crops domesticated from wild plants
• Need genetic diversity to develop future crops
• Ecological services
• Genetic information
• Recreation
• Eco-tourism
• 1 male lion living to age 7550K or 1000 if
  killed by a poacher for its skin
• Ethical considerations

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Preserving Biodiversity
PRESERVE HOT SPOTS
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US Endangered Species Act (1973Nixon!)

• Provides a program for the conservation of
  threatened and endangered plants and animals and
  the habitats in which they are found
• Dept of Interior maintains the list of 632
  endangered species (over 50 plants) and 190
  threatened species
• Anyone can petition the US FWS to add a species
  to the list (if it is in danger of extinction in
  all or most of its range)
• Can be listed b/c of habitat destruction,
  overexploitation, disease/predation, inadequacy
  of existing regulations, any human threat to its
  continued existence
• Law prohibits any action (either administrative
  or real) that results in the taking of a
  listed species OR ADVERSELY AFFECTS HABITAT
• Illegal to take, possess, sell, transport listed
  sp.
• Recovery Plan is written for each species
• Provides for acquire land that preserves these
  species

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CITIES

• Convention on International Trade In Endangered
  Species
• Is an international agreement between
  Governments. Its aim is to ensure that
  international trade in specimens of wild animals
  and plants does not threaten their survival
• Annually, international wildlife trade is
  estimated to be worth billions of dollars and to
  include hundreds of millions of plant and animal
  specimens.
• The trade is diverse, ranging from live animals
  and plants to a vast array of wildlife products
  derived from them, including food products,
  exotic leather goods, wooden musical instruments,
  timber, tourist curios and medicines.
• Levels of exploitation of some animal and plant
  species are high and the trade in them, together
  with other factors, such as habitat loss, is
  capable of heavily depleting their populations
  and even bringing some species close to
  extinction.
• Many wildlife species in trade are not
  endangered, but the existence of an agreement to
  ensure the sustainability of the trade is
  important in order to safeguard these resources
  for the future.
• Voluntary adherence
• CITES works by subjecting international trade in
  specimens of selected species to certain
  controls. These require that all import, export,
  re-export and introduction from the sea of
  species covered by the Convention has to be
  authorized through a licensing system.