Chapter 9 Review
Jamie Bell
9-1
 Humans have caused the extinction rate to
increase by converting grasslands, forests, and
wetlands into urban areas. Climate change is
also a large factor in extinction. Scientists
document records of fossils to try and compare
extinction rates from back then to present time.
They have predicted that species and
biodiversity loss will increase by the next 50-100
years. An Endangered Species Act has been put
in effect.
Vocabulary Review
 Biological extinction (when a species can no longer be
found anywhere on earth)
 Background extinction rate (natural, low rate of
extinction)
 Extinction rate (a percentage or number of species that
go extinct within a certain time period such as a year)
 Mass extinction (the extinction of many species in a short
period of time)
 Endangered species (few individual survivors that the
species could soon become extinct)
 Threatened species (has enough remaining species to
survive short term)
9-2
 The world’s species provide support for our life
system and keep us and other species alive. They
also proved economic services such as food
crops, fuelwood and lumber, paper, and
medicine. We should care because it would take
5 million to 10 million years for natural speciation
to rebuild the biodiversity. Species also have the
right to exist so we have a ethnical responsibility
to protect them.
9-3
 The loss oh habitat is a major threat towards
species. Harmful invasive species also accelerate
extinction because they are not used to the
predators, competition, parasites, or pathogens
in the new habitat. This introduction can cause
ecological disruption in the environment. An
example of introducing a new species to an
areas and causing harm is the kudzu vine.
9-3..
 Human population growth accelerates species
extinction because we leave a ecological
footprint due to the damage we cause wherever
we are. This has resulted in the loss of many
species. Pollution and climate change is also a
factor is accelerating extinction. Pollution itself
can wipe out a species and change the climate.
Climate change causes biodiversity to decrease
because it affects the migration of animals and
growth of plants.
9-3…
 Overexploitation speeds up extinction because it
is the act of killing an animal for profit. Many
people illegally kill protected animals. Many
animals have become extinct due to poachers.
This hurts biodiversity because each species plays
a role in their environment. The removal of a
certain species can speed extinction.
Vocabulary Review
 HIPPCO (Habitat destruction, degradation, and
fragmentation; Invasive species; Population
growth and increasing use of resources; Pollution;
Climate change; and Over exploitation)
 Habitat fragmentation (When a large, intact
area of habitat such as a forest or natural
grassland is divided)
9-4
 The rising rate of extinction can be reduced by
enforcing laws to protect the biodiversity.
National environmental laws and international
treaties can tell people how to regulate pollution,
killing of animals, and the way certain land is
being used. These laws can also provide wildlife
sanctuaries that could preserve the biodiversity
of an area.