Transcript Biodiversity

… In wilderness is the
Preservation of the world.
A mass extinction is the
Extinction of many species during
A relatively short period of time.
The earth has experienced
5 mass extinctions, each
Probably caused by some change
In climate.
Many scientists believe that we
Are living in another mass
Extinction that would leave
25% of all species extinct
By the year 2100.
If this is true, it will be the
First caused by an organism…
Humans!
The term biodiversity refers
To the number of variety
Of species on Earth.
Of the approximately 1.6 million
Species on earth, most
Are insects.
The human population is
Increasing by about 220 000
People each day!!
Because the human population
Is growing so rapidly, we are
Causing other species to
Become extinct at an
Accelerated rate.
As human populations grow, we
Use more land to build homes
And harvest resources.
It is estimated that habitat loss
Causes almost 75% of the
Extinctions now occurring.
Most extinctions are
Occurring in tropical rain forests
When land is cleared for
Farming or cattle grazing.
Unregulated hunting can also
Lead to species extinction.
In the early 1900’s the American
Passenger pigeon was
Legally hunted to extinction.
Similarly, the American buffalo
Was nearly hunted to extinction
In the 1800’s.
In many countries, Poaching
(illegal hunting), can threaten
Animals with extinction.
This happened to elephants
In 1979 when poachers were
Hunting the beasts to meet
the demand for ivory tusks.
An exotic species is a species that
Is not native to a particular
Region.
Even such familiar organisms
Such as cats and rats, are
Considered to be exotic when
They are brought to regions
Where they have never
Lived before.
Species, along with abiotic
Factors, are what make
Up ecosystems.
Each species plays a role
In its ecosystem.
Some species are so important
To the functioning of an
Ecosystem that they are
Called keystone species.
When sea otters were hunted
To near extinction on the
Pacific coast, their entire
Ecosystem was disrupted.
There are also practical uses
For certain species.
About 40% of all prescription
Drugs were derived from
Living things.
So scientists are concerned
That the loss of biodiversity,
Especially in the Rain forests,
Will limit the development
Of future medicines.
The united states congress
Passed the Endangered Species
Act in 1973 and has amended
It several times.
This law is designed to
Protect plant and animal
Species in danger of extinction.
There are 4 main provisions…
Under the 1st main provision,
The US Fish and Wildlife
Service must compile a list of
All endangered and threatened
Species.
To be considered endangered,
A species numbers must have
Fallen so low that it is likely
To become extinct in the
Near future.
Threatened species are species
That are likely to become
Endangered if they are
Not protected.
The second main provision states
That endangered or threatened
Animals may not be caught.
None of the species, nor any
Of their parts, can be sold
Or traded.
According to the 3rd provision,
The federal government
May not carry out any project
That jeopardizes an
Endangered species.
And the 4th provision says that
A recovery plan for each
Endangered or threatened
Species.
There are also international
Organizations to help species.
The world wildlife fund works
To protect biodiversity,
Especially in rain forests.
The Nature Conservancy
Currently manages over
1500 nature sanctuaries.
Greenpeace International
Stages dramatic protest to stop
The killing of animals.
The international union for the
Conservation of nature and
Natural resources is in the
Forefront of efforts to protect
Species and habitats.
It is possible to slow the loss of
Species, but to do so we must
Develop new approaches to
Conservation and a sensitivity
To human needs around the globe.
Additional ways to preserve
Individual species include
Captive-breeding programs,
Botanical gardens, and
Germ-plasm banks.
Germ-plasm banks store germ
Plasm for future use in case
Species become critically
Endangered.
Germ-plasm is the genetic material
Contained within the reproductive
Cells of organisms.
Zoos and wild-animal parks
Can increase the population
Of an endangered or
Threatened species by
Establishing captive-breeding
Programs.
Such programs involve breeding
Animals under carefully
Managed circumstances.
Botanical gardens worldwide
House 90 000 species of plants.
Even so, the gardens don’t have
The space of the funds to
Preserve most of the worlds
Rare and threatened plants.
Recently, many
Conservationists have begun
To concentrate on protecting
Entire ecosystems.
This helps to save many organisms
That can’t be placed on lists
And these ecosystems can
Help save the entire planet.