Transcript biological diversity

Chapter 10 - Biodiversity
Biodiversity
 The number and variety of species in an area.
 short for biological diversity
 Earth has 1.7 million known species but think
there could be as many as 10 – 50 million.
 Most known species are insects.
Levels of Diversity
 Biodiversity is studied and described in levels:
1. Species Diversity – this is the level commonly meant
when referring to biodiversity. The study of
differences in species/populations of species.
Levels of Diversity
2. Ecosystem Diversity – the study of different types of
ecosystems and their ecological processes.
Levels of Diversity
3. Genetic Diversity – the study of genetic variation within
populations.
Importance of Species Biodiversity
1. To Preserve Ecosystems
 Every species interacts in some way with other
species.
 Some species are crucial to the functioning of
an ecosystem. These are keystone species.
1880’s
Importance of Species Biodiversity
 2. To Preserve Genetic Variation
 species with a high level of genetic diversity are
better equipped to deal with ecological pressures such
as drought or disease.
 When population numbers get really low a
bottleneck occurs and only a limited number of genes
survive. This lowers the chance for long-term survival
of the species.
Importance of Species Biodiversity
 3. To Be Used By Humans
 For Food
 For Recreation
 For Shelter/Clothing
 For Medicines
Pacific Yew=Taxol
for cancer treatment
 ¼ of all medicine
comes from plants
 almost all
antibiotics come
from fungi
Loss of Biodiversity
 Extinction is a natural process.
 Over 90% of species that have ever existed
are extinct- most without the influence of man
 When a large number of species die in a
short period of time, it is called mass extinction.
 The mass extinction occurring now is
different because it is being caused primarily
by the actions of mankind.
Human Causes of Extinctions
 1. Habitat Destruction
 Habitat Destruction accounts for 75% of extinctions.
 Because species are adapted to certain types of
habitats, loss of those areas have caused the most
extinctions.
Human Causes of Extinctions
 2. Introduction of Exotic Species
 Moving species to areas they are not
indigenous to (usually by humans).
Kudzu in Southern USA
Rabbits in Australia
Human Causes of Extinctions
 3. Poaching
 The illegal hunting or harvesting of animals.
 Especially a problem in less developed countries.
 Can result in unintentional artificial selection
Human Causes of Extinctions
 4. Pollution
 Can cause poisoning , suffocation, and many
other life threatening issues for animals.
Areas of Most Concern
1. Tropical rainforests – are the most biologically
diverse terrestrial biome, housing over ½ the
world’s land species.
Areas of Most Concern
 2. Coral Reefs/ Coastal Regions
 Extremely diverse ecosystem - threatened by coastal
development and pollution
Areas of Most Concern
 3. Islands
 Islands have few but distinct species.
 Have real problems with the introduction of
exotic species.
Brown Snake in Hawaii has
driven many native birds to
extinction.
Areas of Most Concern
 4. Hotspots
 Places with large numbers of biodiversity but in danger
from human activity
Preservation
of these
regions
would be
the most
effective
way to slow
the loss of
biodiversity.
What’s Being Done
 1. Captive Breeding Programs
 Capturing wild species to breed in captivity and then
returning to the wild.
The Giant Panda is also a species benefitting
from captive breeding programs
9 California Condors remained in 1986. By 2002- 58 were
released into the wild and 102 were living in captivity
What’s Being Done
 2. Germ Plasm Banks
 The collection and preservation of genetic material
in a controlled environment.
What’s Being Done
 3. Zoos and Botanical Gardens
 Keeping live species for preservation, breeding, and
education
What’s Being Done
 The Endangered Species Act
 The US has the toughest laws in the world regarding
endangered species.
Four Main Points:
1. The US Fish and Wildlife Service must compile a list
of all Threatened/Endangered Species.
2. Threatened/Endangered Species may not be caught
or killed, uprooted, or any part of them traded or sold.
The only exception is if you have a permit that allows
you to have them for study purposes.
3. Federal Government may not carry on projects that
will jeopardize threatened/endangered species.
4. US Fish and Wildlife Service must develop a recovery
plan for each threatened/endangered species.
The Ecosystem Approach
 Scientists advocate the preservation of entire
ecosystems to protect biodiversity because a
healthy biosphere requires intact ecosystems.
 By saving entire ecosystems, we save all
species instead of individual species.
International Efforts to Protect
Biodiversity
 Committee on International Trade of Endangered Species
 CITES - international ban on ivory 1989
 Biodiversity Treaty
 signed at Earth Summit Rio 1992- to preserve species and
habitats in many different countries.
Private Conservation Efforts
 WWF- The World Wildlife Fund
 The Nature Conservancy – buys land for preserves and
sets up education programs
 Greenpeace – radical organization devoted to
protecting species.
THE END