Biodiversity

Day 6

What is Biodiversity?The variety of life in an area that is determined by the number of different species in that area.

• There are 2 main types:

1) Genetic Diversity 2) Species Diversity

The variety of genes in a population

Number of different species in a community

Why is biodiversity important?

Teosinte: A distant relative of

corn w/ resistance to viral diseases

Domestic corn plant

Penicillin: Derived from bread mold

Madagascar Periwinkle: Used to treat childhood forms of leukemia

1)Direct economic value

2)Indirect value – ex. treatment of diseases

Extinction Rates

• The gradual process of becoming extinct is known as background extinction.

• Mass extinctions: When a large percentage of all living species become extinct in a relatively short period of time.

• 250 MYA: Over90% of species died

Estimated number of Extinctions since 1600

Group Main-land

Island Ocean Total Approximate Number of Species

Percent of Group Extinct

Mammals 30 51 4 85 4000 2.1

Birds 21 92 0 113 9000 1.3

Reptiles 1 20 0 21 6300 0.3

Amphibians 2 0 0 2 4200 0.05

Fish 22 1 0 23 19,100 0.1

Invertebrates 49 48 1 98 1,000,000+ 0.01

Flowering Plants

245 139 0 384 250,000 0.2

Five Most Recent Mass Extinctions

Ordovician Period (444 MYA)

Devonian Period (360 MYA)

Permian Period (250 MYA)

Triassic Period (200 MYA)

Cretaceous Period (65 MYA)

Activity: Understanding Geological Time

• Working in your groups, you will get the following supplies:– A meter stick– A roll of 5 meters of paper– Colored pencils

• Using the worksheet, plot out the dates. – 1 million years is a millimeter– 1 billion years is a meter