BiodiversityCh10, Section 1: What is Biodiversity?

Standards: SCSh2b, 3c, 4a, 9c

Biodiversity- number of different species in a given area.

Highest in areas that get lots of sunlight, moisture, and nutrients- like a tropical rainforest.

What is biodiversity?

Unknown! We know 1.7 million have

been identified and named.

Estimate greater than 10 million actually exist.

Many unknown species live in rainforest, deep oceans, even cities.

Which group of organisms make up the majority of the 1.7 million known species?

How many species are on Earth?

Genetic diversity◦ Different genes within

all members of a population.

Species diversity◦ Number of different

species in an area. Ecosystem diversity

◦ Variety of habitats, communities, and ecological processes within and btwn ecosystems.

What are 3 types of biodiversity?

1. Species are part of balanced cycles within ecosystems

2. Maintain genetic diversity

3. Provide products for human use

4. Ethical, aesthetic, and recreation uses

What are the benefits of biodiversity?

1. Species are part of balanced cycles within ecosystems

◦ All species depend on each other as food sources

◦ Keystone species- when removed from an ecosystem, the ecosystem collapses Named after center block in

an arch that supports arch (see picture)

Ex: sea otter, salmon, grey wolf (Yellowstone)

What are the benefits of biodiversity?

Sea otters were killed almost to extinction in the 1800’s for their fur.

Sea otters eat sea urchins but since there were no sea otters, the sea urchin population grew exponentially.

Sea urchins devoured kelp which was home to numerous species of fish and invertebrates.

Without kelp the entire ecosystem suffered.

Sea urchins devouring kelp stalk

2. Maintain genetic diversity

◦ Need diversity to keep population healthy.

◦ If all species are genetically identical then an environmental change could wipe out the population.

◦ Creates bottleneck effect◦ Ex: Cheetahs- there are so

few cheetahs left that they begin to inbreed and lose genetic diversity. Suffering from genetic disorders & disease.

What are the benefits of biodiversity? Before cheetahs

were killed off there was a lot of genetic diversity.

Cheetahs population killed rapidly

Very few traits survived.

3. Provide products for human use

A. Medicine 1/3 of drugs derived

from plants Almost all antibiotics

from chemicals in fungi Ex: see chart

Drug Origin Use

Taxol Pacific yew Anticancer

Novacaine Coca plant Local anesthetic

L-dopa Velvet bean

Treatment of

Parkinson’s disease

What are the benefits of biodiversity?

B. Food◦ Eating food from

rainforests ensures protection of the rainforest b/c it becomes an exporting industry Ex: chocolate

◦ Need to create hybrids so crop genes aren’t too pure. (pure genes=increased susceptibility to disease

◦ Many undiscovered and underutilized crops in developing countries that could be used to provide income.

What are the benefits of biodiversity?

C. Clothing◦ Ex: cotton, silk

D. Shelter◦ Ex: wood, rubber

from rubber trees

What are the benefits of biodiversity?

4. Ethics, Aesthetics, Recreation

◦ Ethics- species have a right to exist

◦ Aesthetics- personal enjoyment; camping, picking wildflowers, hiking

◦ Recreation- fishing, swimming, boating

◦ Ecotourism- form of tourism that supports conservation efforts; enables developing countries to earn income.

What are the benefits of biodiversity?