BiodiversityVariety of the earth’s species, the genes they contain, the ecosystems in which they live, and the ecosystem processes such as energy flow and nutrient cycling that sustain all life.

Hot Spots A hotspot is an area where there are

many threatened and endangered species

There are currently 34 hotspots in the world today

Species Diversity Number and abundance of species

present in different communities

Ecological Diversity The variety of terrestrial and aquatic

ecosystems found in an area or on the earth

Functional Diversity The biological and chemical processes

such as energy flow and matter recycling needed for the survival of species, communities and ecosystems Food Chains & webs

Genetic Diversity The variety of genetic material within a

species or a population

Theory of Natural Selection Explains how life has evolved from a

common ancestor

Survival of the fittest Organisms suited for the environment

will survive to reproduce, thus passing down desirable traits. Examples:

Giraffes Camels Influenza virus Venus fly trap

NOTE – fittest does not equal strongest!!!

Natural Selection and Geological Processes Location on the earth influences

biodiversity (rainforest vs. tundra) Continental movement

Earthquakes and volcanoes Climate change

Cyclic cooling and heating of the earth Catastrophic events

Asteroid impacts, major volcanic eruptions

Continental movement Theory of Continental Drift The earth has large plates located

between the lithosphere and asthenosphere

These plates move very slowly (1-3cm/yr)

This creates oceans, mountain ranges, volcanoes, earthquakes, trenches

225 million years ago

Fig. 4-5, p. 88

135 million years ago

Present65 million years ago

225 million years ago

Continental Movement

Climate Change

Climate Change and Natural Selection

Changes in climate throughout the earth’s history have shifted where plants and animals can live.

Figure 4-6

Catastrophic events Asteroid impacts Super Volcanoes

These affect biodiversity locally and on a world-wide scale

Speciation - formation of a new species Two Phases

1. Geographic isolation A population is removed from others of it’s

species for a long period of time 2. Reproductive isolation

The removed population becomes so genetically different over time that it can no longer interbreed with others of it’s species

Measurements of Biodiversity Species diversity – the number of

different species in a community

Species evenness – the abundance of species in a community

Richness and Sustainability Higher species richness = higher

productivity = higher sustainability

Reasons: More likely to withstand droughts, disease,

climate change, nutrient shortages Higher number of producers lead to a

higher biomass which leads to more carbon and nitrogen cycling

Extinction – the loss of a species Background extinction – low rate of

extinctions

Mass extinction-high rate of extinctions due to specific cause Climate change

Three types of extinctions Local: A species is no longer found in an

area it once inhabited but is still found elsewhere in the world.

Ecological: Occurs when so few members of a species are left they no longer play its ecological role.

Global (biological): Species is no longer found on the earth.

Global Extinction

Some animals have become prematurely extinct because of human activities.

Figure 11-2

Steps to extinctionBackground extinctions:

1. Rare2. Threatened3. Endangered4. Extinct

Endangered and Threatened Species: Ecological Smoke Alarms

Endangered species: so few individual survivors that it could soon become extinct.

Threatened species: still abundant in its natural range but is likely to become endangered in the near future.

Figure 11-3

Red lists ICUN – International Union for the

Conservation of Nature and Natural Resources

Published list of threatened species www. iucnredlist.org

Some species are more prone to extinction: K-strategists Specialists Tertiary consumers Fixed migratory patterns Narrow distribution Commercially valuable Large territories

Fig. 11-3, p. 224

Grizzly bear Kirkland’s warbler

Knowlton cactus

Florida manatee

African elephant

Utah prairie dog Swallowtail butterfly

Humpback chub

Golden lion tamarin

Siberian tiger

Fig. 11-3, p. 224

Hawksbill sea turtle

Giant panda Black-footed ferret

Whooping crane

Northern spotted owl

Blue whale

Mountain gorilla Florida panther

California condor

Black rhinoceros

Fig. 11-8a, p. 230

Range 100 years ago

Indian Tiger

Range today(about 2,300 left)

Fig. 11-8b, p. 230

Range in 1700

Black Rhino

Range today(about 3,600 left)

Fig. 11-8c, p. 230

Probable range 1600

African Elephant

Range today

Fig. 11-8d, p. 230

Range today(34,000–54,000 left)

Asian or Indian Elephant

Former range

Extinction Rate The percentage of species that go

extinct within a certain time period

The current extinction rate is increasing at an alarming rate due to human activities

History of Extinctions

Extinctions have existed long before humans had an influence

The current extinction crisis is the first to be caused by a single species- US!

. This is happening faster than ever; a few decades versus thousands to millions of years.

Humans are eliminating not only the species but, the environment. Ex. Tropical rainforest

Endangered Species

Effects of Humans on Biodiversity

The scientific consensus is that human activities are decreasing the earth’s biodiversity.

Figure 4-13

Human Caused ExtinctionCauses include:

HIPPO C Habitat Destruction Invasive species Population Growth Pollution Over-harvesting Climate Change

Fig. 4-12, p. 93

Tertiary

Bar width represents relative number of living speciesEra Period

Species and families experiencing

mass extinction

Millions ofyears ago

Ordovician: 50% of animal families, including many trilobites.

Devonian: 30% of animal families, including agnathan and placoderm fishes and many trilobites.

500

345

Cambrian

Ordovician

Silurian

Devonian

Extinction

Extinction

Pal

eozo

icM

eso

zoic

Cen

ozo

ic

Triassic: 35% of animal families, including many reptiles and marine mollusks.

Permian: 90% of animal families, including over 95% of marine species; many trees, amphibians, most bryozoans and brachiopods, all trilobites.Carboniferous

Permian

Current extinction crisis causedby human activities. Many speciesare expected to become extinctwithin the next 50–100 years.Cretaceous: up to 80% of ruling reptiles (dinosaurs); many marine species including manyforaminiferans and mollusks.

Extinction

Extinction

Triassic

Jurassic

Cretaceous

250

180

65Extinction

ExtinctionQuaternary Today

Natural Extinctions

Causes include Climate change Change in ecosystem Lack of adaptations to change

How do extinctions affect us? Use value lost – medicinal use,

recreation, crops, lumber Economic value – ecotourism (African

safari) Genetic information – genetic diversity

lost Non-use values – appreciation

Case Study: The Whooping Crane

Habitat loss and unregulated hunted led to a severe decrease in the species

In 1941 there were an estimated 14 whooping cranes left in the wild

The decline in this species was a major factor leading up to the creation of the Endangered Species Act

Saving the Whooping Crane

Ex-situ conservation: Conservation outside of the natural habitat

In-situ conservation: Conservation in the natural habitat

A combination of techniques was used to save the Whooping Crane

Teaching migration

The Endangered Species Act Established in 1973 Overseen by the US Fish and Wildlife

Service Penalties of violating the act: http://

www.gc.noaa.gov/schedules/6-ESA/EnadangeredSpeciesAct.pdf

Funded by US taxes and penalty money

The Act: authorizes the determination and listing of species as

endangered and threatened; prohibits unauthorized taking, possession, sale, and

transport of endangered species; provides authority to acquire land for the conservation

of listed species, using land and water conservation funds;

authorizes establishment of cooperative agreements and grants-in-aid to States that establish and maintain active and adequate programs for endangered and threatened wildlife and plants;

authorizes the assessment of civil and criminal penalties for violating the Act or regulations; and

authorizes the payment of rewards to anyone furnishing information leading to arrest and conviction for any violation of the Act or any regulation issued thereunder.

Case Study: The U.S. Endangered Species Act

Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S.

Figure 11-18

CITES Convention for the International Trade of

Endangered Species - CITES Is a voluntary agreement among

participating countries to stop the trade of listed species

180 countries participate: 5,600 animal species and 30,000

animals are protected under this act

Deforesting the Rainforest The rainforest provides half of the

world’s hardwood 80% of the Rainforest’s nutrients are in

the top, organic layer(O-layer) After a Rainforest has been clear cut, it

will not re-grow Usually, deforested rainforests are

replaced with grassland

Neem Tree Provides:

Fuelwood & Lumber Infection-fighting cabability Birth control – seeds contain a strong

spermicide

Fragmentation Habitat fragmentation is when an

ecosystem is divided by a highway, neighborhood, buildings or other structures/land uses.

Leads to: Decreased genetic diversity Loss of habitat Loss of breeding grounds May disrupt migration patterns Disruption of food chains

Fishing

Deadliest Catch

The major decline in the worldwide catch of fish since 1990 is because of over-fishing.

By-catch- fish or animals that were not meant to be caught.

Fishing Problems & Techniques

About 75% of the world’s commercially valuable marine fish species are over fished or fished near their sustainable limits. Big fish are becoming scarce. Smaller fish are next. We throw away 30% of the fish we catch. We needlessly kill sea mammals and birds.

Overfishing and Extinction: Gone Fishing, Fish Gone

Fig. 12-A, p. 255

Fish farming in cage

Trawler fishing

Spotter airplane

Sonar

Trawl flap

Trawl lines

Purse-seine fishing

Trawl bagFish school

Drift-net fishingLong line fishing

Lines with hooks

Fish caught by gills

Deep sea aquaculture cage

Float Buoy

Trawler FishingCatches shrimp, shellfish, flounder

and other anials that live on the ocean floor

Drags a funnel shaped net along the ocean floor, weighted down with chains or metal plates

Some nets are large enough to hold 12 jumbo jets!!

Purse Seines

A large purse-like net is put into the ocean and is then closed like a drawstring purse to trap the fish.

Tuna is a fish typically caught in purse seines

Dolphins are a by-catch of purse seines

Purse Seines

Lines are put out that can be up to 80 miles long w/ thousands of baited hooks on them. These are left out free-floating for days and then the boat comes back and picks them up.

Pilot whales, dolphins, sea turtles, and birds are by-catch of this technique.

Deadliest Catch

Long-line fishing

Each net hangs as much as 50 feet below the surface and up to 34 miles long.

Anything that comes into contact w/ these nearly invisible nets are entangled.

This leads to overfishing Many unwanted fish and marine mammals, turtles and

seabirds are caught.

Drift-net fishing

Regulations on Fishing Marine and mammal protection act -

provides for protection and conservation of marine mammals

Magnuson Act- Sets quotas, size limits and seasons for fishing

UN Law of the Seas – allows countries to establish fishing quotas

Marine Sanctuaries Act- provides protected habitat for marine organisms