Sustaining Biodiversity: The Species Approach

1. Sustaining Biodiversity: The
Species Approach
Josh Li, Mike Smith, and Jay Zhou

2. Biological Extinction: The disappearance of a
species from Earth
Background Extinction: Continuous, low level of
extinction of species over 3.65 billion years
Mass Extinction: Loss of many species in a short
period of time
Extinction Rate: Percentage or number of species
that go extinct each year
Key Terms

3. ● Human activities increase the pace of extinction
● Since the arrival of humans, background
extinction rates have increased 100-1000 times
(currently 0.01- 0.1% per year)
● Extinction rates are estimated to rise to ~1% per
year by the end of the century, causing ¼ to ½ of
species to become extinct
● Biodiverse hotspots (estuaries, rainforests) are
being degraded, reducing the emergence of new
species
Humans’ Role in Species Extinction

4. Endangered Species: Few individual survivors
that may soon become extinct over its
indigenous range
● Ex: Black rhino, blue whale, giant panda
Threatened/Vulnerable Species: Still abundant
in its natural range, but soon to become
endangered
● Ex: Great white shark, marine iguana, polar bear
Near-Extinct Classifications

5. ● Species are vital to Earth’s life support system
● Support our economy by providing ecotourism and
components of various products and medicines
(cancer drugs)
● It will take millions of years to rebuild biodiversity
● Species have a moral right to exist, regardless of
their usefulness
Reasons to Prevent Species Extinction
Pacific yew: Used to treat
Ovarian Cancer

6. ● HIPPCO describes premature extinction of
species: Habitat destruction/fragmentation,
invasive species, population and resource use
growth, pollution, climate change, and
overexploitation
● Loss of wetlands, clearing of rainforests, and
plowing of grasslands are extremely detrimental
to biodiverse ecosystems
● Habitat fragmentation is the division of large,
contiguous habitats into isolated patches
How Humans Accelerate Species Extinction

7. ● Non-native species, whether accidental or deliberate, often
threaten or endanger native species
○ They have no natural predators and can trigger ecological disruptions
● Overpopulation and overconsumption of resources can eliminate
habitats
● Pollution from chemicals such as pesticides can damage small
ecosystems. Human pollution also causes climate change, which
causes habitat loss
● Global demand for vulnerable/endangered species as food or pets
has increased poaching, which lowers biodiversity
HIPPCO cont.

8. ● Treaties such as the 1975 Convention on International
Trade in Endangered Species protect 900 species from
commercial trading and restricts trading of 29,000 species
○ Unfortunately difficult to enforce and many nations did not
sign
● A sanctuary approach can be used to protect wildlife; 548
federal refuges exist, but habitats require more funding
● Gene banks, botanical gardens, farms, aquariums and zoos
can be used to support species until they are ready for
reintroduction into the wild
Protecting Species from Extinction

9. ● Generally, the safest approach is
to use the precautionary
principle
● If there’s evidence that an
activity harms human health or
the environment, we should take
measures to reduce or prevent
the damage
Precautionary Principle