Biodiversity

• Ecosystem Diversity • Biodiversity• Natural selection• Evolution• Ecosystem services

Biodiversity

• Organisms can be classified based on:– How they get energy

• Chemo - ; photo -

– How they get a source of carbon• Auto - ; hetero-• Photoautotroph – plants, algae• Chemoheterotrophs – animals, bacteria, fungi

– How they use oxygen • Aerobic, anaerobic, facultative anaerobes

Biodiversity

• Variety of different species and their relative abundance in a given area – Species richness

• Genetic diversity - variety in the genetic makeup of organisms that enables the species to reproduce and gain a competitive advantage

maintaining biodiversity:• Stability - sustainability• Genetic diversity• Medicinal • Agricultural • Industrial - building homes/stuff• Scientific - experimental; new technology• Aesthetic • Ethical • Religious – are we stewards (?)

Extinction• The population cannot adapt to changing

environmental conditions– Global warming– Habitat destruction– Introduction of invasive

species– Overharvesting/hunting

• Multiple extinction events throughout history

SPECIES EXTINCTION

• Species can become extinct: – Local - no longer found in an area it once

inhabited but is still found elsewhere in the world.– Ecological - so few members of a species are left

they no longer play its ecological role.– Global (biological): Species is gone

Change the environment

• Catastrophes increase opportunities for change– Plate movement, volcanic eruptions, and

earthquakes can wipe out existing species and help form new ones.

– Organisms can move with continental drift

• Those organisms with the best traits best traits pass them on to their offspring

http://www.youtube.com/watch?v=xsXQBnZ_xjI

Catastrophes and Natural Selection

• Asteroids, meteorites and geologic processes have wiped out large numbers of species and created evolutionary opportunities by natural selection of new species

135 million years ago

Present65 million years ago

225 million years ago

Recent Extinction

• Overhunting (netting)– Nuisance– Decorative feathers

• Habitat destruction• Pets • Basically: humans

Endangered and Threatened Species• Endangered species - could soon become

extinct• Threatened species: still abundant in its natural

range but is likely to become endangered in the near future.

Causes of Vulnerabilty

• K-strategists – low reproductive rate - whales, pandas, rhino

• Specialized – pandas, everglades kite• Narrow distribution – island, desert species• High trophic level – eagles, tigers, osprey• Commercially valuable – tiger, rhino, elephant• Large territory – condor, panther, grizzly bears

• International Union for the Conservation of Nature and Natural Resources (IUCN) publishes an annual Red List

• 2012 - 19,817 endangered species

• 34 hotspots identified by ecologists as important and endangered centers of biodiversity.

• HIPPO - most important causes of premature extinction– Habitat destruction, degradation, and

fragmentation– Invasive species– Population growth– Pollution– Overharvest

Endangerment: Habitat Destruction

• Deforestation • Population growth

– Urban sprawl– Agriculture

Invasive Species

• Outcompete native species – Breed faster, no predators

• Intentional importation:• Economic advantages – produce ___ or more

of ___ or they eat something– Bees – honey– Kudzu – prevent erosion– Nile perch – more meat for food– Cane toads – eat bugs

• Unintentional invaders – hitch hikersUnintentional invaders – hitch hikers• Zebra musselsZebra mussels• Brown tree snakeBrown tree snake• Pythons, boasPythons, boas• Fire ants Fire ants • Japanese beetlesJapanese beetles

http://www.youtube.com/watch?v=abImqGDzXBo

http://www.youtube.com/watch?v=nmU7etSYYqI

Endangerment: Pollution

• Each year pesticides:– Kill about 1/5th of the U.S. honeybee colonies– 67 million birds– 6 -14 million fish– Non-targeted species

Biomagnification

Overexploitation

• Parts (sharks, rhinos, elephants, tigers, beavers, otters)

• Predators and pests (Indian elephants, tigers, wolves, sharks)

• Pets (parrots, fish, tarantula)• Fishing – tuna, mackerel, crabs• Economic benefits?

http://www.youtube.com/watch?v=aJaWygeuPzQ – shark finning

Preservation of Species

• Protect habitat– National parks and rangers– Escape nets turtles, dolphins

• Education programs • Legislation • Habitat restoration - renew, repair, or rebuild

National Parks

• Most are threatened by human activities– Wood, cropland, minerals, poaching– Many are too small to sustain large-animal

species– Invasive species

Stresses on U.S. National Parks

• Overuse• Inholdings (private ownership) within parks • Air pollution

• Zoos, Aquaria, Gardens• Protection• Breeding programs • Education

Preservation of Species

• Taking the animal out of its habitat to protect it• Ex. Zoo’s

• 2 types: – Egg pulling– Captive breeding

Nature Reserves• Reserves with buffer zones help protect

biodiversity and can be connected by corridors• Costa Rica has consolidated its parks and

reserves into 8 megareserves – Protects 80% of its

biodiversity

http://www.youtube.com/watch?v=u2wOhlWeYpY battle at kruger

Preservation of Species

• Conservation organizations • Greenpeace• WWF

• Habitat Restoration

Reconciliation Ecology

• Bluebird boxes• Bat houses• Replanting with native plants

• Grasses, oak leaf hydrangea

Legislate: Endangered Species Act - 1973

• …”protect imperiled species from extinction as a consequence of economic growth and development untempered by adequate concern and conservation.“

• Administered by USFW and NOAA• Identify and list all endangered & threatened species• Forbids federal agencies (besides defense department)

to carry out / fund projects that would jeopardize an endangered species

• Makes it illegal for Americans to engage in commerce associated with or hunt / kill / collect endangered or threatened species.

Legislation: International Treaties

• Convention on International Trade of Endangered Species (CITES); 1975.• Species that cannot be commercially traded

• Fossils • Ice core samples• DNA, protein similarities

Knowledge of past life from:

Evolution

• Evolution - change in a population’s genetic makeup over many generations

• Changes in proteins/structures/behaviors that provides a survival advantage

Darwin - Natural Selection

• A trait shows up by random chance and is beneficial for survival

• Survive longer = reproduce longer • Natural selection - reproducing the most

descendants with heritable traits• “Survival of the fittest” – Malthus• Organisms do not develop traits because they

need them

Natural Selection

• Natural selection is the mechanism of evolution

• “Descent with modification”– Traits are inherited

from an ancestor – History of life is a tree

with many branches– Biodiversity

Evolution of insecticide resistance in insects

Gene pool

• Gene pool – all the genes of a population • Evolution – change in gene frequency of the pool

Sources of Genetic Variation

• Mutation – change in DNA– Errors during mitosis– Exposure to mutagenic agents (UV, radiation)– Virus infection – bacterial resistance/virulence

• Random mating – artificial breeding• Hybridization – two different species crossbreed

and produce fertile offspring

Speciation

• Speciation - a new species can arise when members of a population become isolated for a long period of time– Genes change– Can no longer produce fertile offspring if reunited

Geographic Isolation

Biodiversity Summary

• Evolution increases biodiversity• New species evolve by natural selection

– Survival of the fittest– Descent with modification

• New traits enter the gene pool by:– Mutation – changes in DNA– Random mating– Hybridization

• Humans reduce biodiversity– HIPPO