Extinction and AdaptationExtinction and Adaptation

Biodiversity on EarthBiodiversity on Earth

What is Biodiversity?

• Variety of species of organisms present on Earth.– Includes members of all 5 kingdoms

• Animal – multi-cellular heterotrophs• Plant – multi-cellular autotrophs• Fungi – multi-cellular saratrophs• Protista and Monera – unicellular &

simple cellular colonies– Amoeba Bacteria

Is Biodiversity Important?• Yes

– Think about a food chain• What happens if one “link” is taken out?

• Today nearly 2 million species have been discovered and named by scientist.

• The number of different species decreases each year.

• For more information on importance of biodiversity go to: http://encarta.msn.com/encyclopedia_761579557/Biodiversity.html

Causes of Extinction

• Man-Made– Pollution– Global Climate

Changes– Over-harvesting– Loss of Habitat– Invasion Species

• Natural– Global Climate

Changes– Loss of Habitat– Invasion Species

http://library.thinkquest.org/25014/why/index.html

Survival

• When a species changes to live in its environment, it is said to have adapted.

• Adaptation can be simple or complicated.– Coral fish– Giraffe

Natural selection

• As a species adapts, members that have favorable traits for survival will live to produce offspring, and others will die.– This is how survival adaptations get

passed to the next generation.• Coloring schemes• Burrowing and/or sleep habits.• Migration patterns

Human adapt too.

• We’ve all heard of the fight or flight response, but what is it?– When humans first started hunting for

food, their bodies developed a hormonal response to emergency situations.• Blood vessels dilate, eyes widen, heart

and breathing rates increase and muscles tense ready to fight for their life or run.

• This response kept the hunters alive.• This response can be seen even in

humans today (many thousands of years later) <Demonstration>

• Humans are among the best of the animal kingdom at surviving.– Not only do our bodies adapt but we can

use our minds to invent and engineer ways of surviving in extreme conditions such as space.

Review

• Biodiversity is…• Major causes of extinction…• Adaptation is…• How does adaptation allow for

species survival?• Name some ways humans adapt?