What is Biodiversity?

10.1

A. Biodiversity = biological diversity = number of different

species in an area.1. Example of area rich in biodiversity:

Tropical rainforests, coral reefs2. Impoverished = area that has lost

the biodiversity. Ex. Hawaii

A. Biodiversity = biological diversity = number of different

species in an area.

3. Unknown biodiversitya. 1.7 million species identified. Most are

insects. b. Estimate of total number of species is 5-100

million1)i.e. lots of unknowns!

4. Levels of biodiversitya. Species diversity – number of species in

an area. What is usually meant by biodiviersity.

b. Ecosystem diversity – the variety of habitats, communities, and ecosystem properties.

c. Genetic diversity – all of the different genes contained within a population.

1) Ex. People in this room –large genetic diversity. People in your family—lower genetic diversity.

2) Ex. Crop of corn (monoculture) very low genetic diversity.

3) Genetic diversity is required for differential survival.

B. Benefits of biodiversity

1. Species are connected to ecosystems.

a. Every species is dependent on and depended upon by other species. Each species that is removed may affect one or more other species in the ecosystem.

b. Some species are critical to the functioning of an

ecosystem. Keystone species Ex. Sea otters in kelp forest ecosystems keep the

populations of sea urchins in check, which will otherwise devour the kelp that make up the forests. Their importance was only realized when overhunting greatly reduced the otter populations.

Other examples: African elephants—maintain the savanna ecosystem by knocking over/removing trees and shrubbery. Pisaster starfish preferentially feeds on a species of competitively superior mussels. The starfish presence maintains local diversity.

2. Species and population survival

a. Genetic diversity increases the chance that some of the members will survive environmental changes.

When population is decreased, such as in overharvesting or ecosystem fragmentation, genetic diversity decreases. inbreeding. Ex. Isolated population of cougars in Florida and

other parts of US are suffering from diseases caused by inbreeding.

Some genetic diseases are common among the Ashkenazy Jews—thought to be the result of a small founder population who may happen to have had these traits, and this population was genetically isolated due to political and religious reasons.

3. Medical, industrial, and agricultural

a. ¼ of prescribed drugs are from plants. Most antibiotics are from fungi.

b. Undiscovered species represent a source of potential products.

3. Medical, industrial, and agricultural

c. Most crops we eat originated from few areas of biodiversity. Some are hybrids of variety of species.

d. Depending on too few plants variety is risky. A disease could wipe out an entire cropfamine

Wild Brassica oleracea

Kale

Collard greens Chinese broccoli

Kohlrabi

These are ALL Brassica oleraceai.e. same species!

4. Other values

"Who are we, Homo sapiens, to destroy the creation, however you believe the creation came about. As one act of God or whether you believe as most scientists do that it came about through billions of years of evolution. Nonetheless it is an extraordinary gift that our generation receives its natural heritage and to destroy a large part of it just fundamentally seems wrong especially when you think what we are doing to future generations. There is a spiritual value, an aesthetic value, a psychological benefit, for having a large diversity of life on earth, we should not be removing it." --E.O. Wilson

4. Other values

a. Ethical & moral values1) species have the right to exist. Should

humans be the ones to take it away?2) Earth & it’s species are gift.

b. Aesthetical and personal enjoyments

1) watching wildlife, pets, picking flowers, fishing, hunting, etc.

2) Ecotourism