Download Biodiversity and Extinction chapter 11.3

Biodiversity and Extinction
chapter 11.3
How Do New Species Form?
A new species can form when a group of
individuals remains isolated from the rest of its
species long enough to evolve different traits
that prevent reproduction.
What Factors Affect Biodiversity?
Biodiversity is the number of different species
found in an area.
The factors that affect biodiversity are:
1. Area
2. Climate
3. Genetic diversity
4. Diversity of niches
Area
Within an ecosystem, a large area will usually
contain more species than a small area.
You will find more rabbits in a large field than a
small patch of grass.
Climate
Climate affects the different
species in a certain area.
The biodiversity in a tropical
rain forest will be grand
because tropical forest are
huge, warm, have lots of
moisture and will probably
support more organisms
with food and resources.
A tundra would have less
biodiversity because of it’s
harsh cold climate. Only few
organisms could survive in
such environment.
Genetic Diversity
Diversity is very important within a species.
Different colors and sizes are traits determine by genes, which
organisms inherit from parents.
Organisms of the same species share many genes however
individuals also have different genes.
The more diversity in a gene pool of a species the better
changes of survival.
Niche Diversity
A niche is the role of an organism in its habitat,
or how it makes its living.
The more different organisms the more different
niches, the more diversity.
Why do species go extinct?
Extinction is when all the members of the same
species disappear from Earth.
Extinction usually occurs when a species is
unable to adapt within a changing environment.
Process of Extinction
Species in danger of becoming extinct in the
near future are called endangered species.
Species that could become endangered species
in the near future are called Threatened species.
Extinction And Human Activity
Extinction is a natural process that happens
gradually.
However sometimes human activity can speed
the process of extinction for certain species.