1. Topic 1: Biological Diversity and Survival
Variations
Biological Diversity
Biological diversity is important for the health and survival of natural communities.
Species
Organisms are grouped together as a species when:
they interbreed in nature.
their offspring are able to breed.
***Organisms that show similar characteristics, (number of legs, type of eye etc.) are not necessarily their own species. ***
Speciation
Similar species, (bears, wild cats, dogs) are thought to have come from a common ancestor and then evolved over time. The evolutions that occurred produced a variety of similar species, (black bear, grizzly bear, polar bear or cougar, lynx, tiger or wolf, coyote, husky).
***Speciation is what is responsible for much of Earth’s biological diversity. ***

2. Adaptations:
All organisms possess certain adaptations to help them survive in their environments. Since organisms differ greatly, (biological diversity), a huge number of adaptations are seen in living things.
There are two different types of adaptations:
Structural Adaptations
This is a physical adaptation that allows an organism to live in an environment. Example: fish have gills this allows them to breathe under water. Without this adaptation they would die.
2. Behavioural Adaptations
This is an inherited characteristic that allows an organism to survive. Example: Geese fly south when the weather begins to get cooler. They do this from birth.
It is important to have a vast amount of variation in an ecosystem.
An ecosystem with many species with variations has a good chance of surviving, (staying healthy) in spite of changes, disease, overuse, etc.

3. Measuring Biological Diversity
In order to determine the diversity of an area biologists use the diversity index.
It is a comparison of the diversity of a species in an area with the total number of organisms in the area.
The index is used to determine the health of the ecosystem. (The higher the index the more healthy the ecosystem is considered to be.)
Assignment: Read Text Pages 2 – 14
Do Text Page 15 # 1 – 3, 5, 6