Transcript BIODIVERSITY & ENDANGERED SPECIES

Biodiversity
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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:
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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 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
225 million years ago
65 million years ago
135 million years ago
Present
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 hikers
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Zebra mussels
Brown tree snake
Pythons, boas
Fire ants
Japanese beetles
http://www.youtube.com/watch?v=nmU7etSYYqI
http://www.youtube.com/watch?v=abImqGDzXBo
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/watc
h?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
Knowledge of past life
from:
• Fossils
• Ice core samples
• DNA, protein similarities
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
Gene pool
Evolution of insecticide
resistance in insects
• 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