Transcript Threatened and Endangered, and Extinct Species

Threatened and
Endangered, and Extinct
Species
Biodiversity
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Extinction – the process by which an organism
is no longer in existence as a species
Extinct organisms
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Dinosaur
Woolly Mammoth
Saber tooth
Dodo bird
Passenger pigeon
Causes of Extinction
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Ice Age
Meteors
Predators
Poaching
Hunting
Habitat Loss
Why are organisms so important?
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Food Chain
Food
Medicine
Protection
Biodiversity
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The different types of
life (streams, wetlands)
Diagram of PA
Biodiversity
Vertebrates
3%
Protist
3%
Fungi, Lichens
17%
Non-insect
invertebrates
7%
Plants, Algae
24%
Insects
46%
Biodiversity is studied on three levels
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Genetic – biodiversity is the difference
between genes of a particular species
Species – grey squirrel vs. Delmarva Fox
squirrel
Ecosystem – biodiversity – stream vs. wetland
Variations
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Differences in the phenotype of a species
Appearance
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Height
Width
Weight
Allow for adaptation to new environments
Organism Niches
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Role an organism plays; two organisms cannot
occupy the same niche
Predator-Prey Relationships
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Mice vs. Weasel
Predators
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Clean up the weak or sick
Help out to remove the weak organisms
Symbiosis
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Two organisms rely on each other for survival
Parasitism
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One organism benefits while the other is
harmed
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Human and tapeworm
Mutualism
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Both organisms benefit
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Rhino and birds
Commensalism
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One organism benefits, other is unharmed
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Birds nest and tree
Adaptations
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Adaptation – special modifications or
characteristics that help an organism better
survive its environment
Structural Adaptation
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Body parts, internal/external, thumbs, tails,
claws, color, fur, beak
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Mimicry – another organism acts like the first
(structural or behavioral)
Camouflage – blend in with your environment
Behavioral Adaptation
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How an organism acts
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Reflexive behavior – caught by surprise
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Cat bird
Lions carrying young
Cat
Snake recoils
Instinctive behavior – you don’t have to be taught
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Mother, baby
Survival of the Fittest
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Natural Selection – the process that makes it
more likely that organisms with the best
characteristics will survive, breed, and pass
them on
Populations evolve so that the most
advantageous adaptations become common
Evolution
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Traits must vary
Adaptations must be genetic
Adaptation must be beneficial for survival
Human impacts
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Negative – destroy lands
Positive
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Endangered – population increases
Capture breeding – zoos
Treat injured organisms
Threatened, Endangered, Extinct
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Threatened – many individuals but numbers
are dwindling
Endangered – so few that extinction is possible
Extinct – no longer exists
Factors that make species more
prone to extinction
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Special food
Special habitat
High on food web
Migrate
Reproduction rate low – 1 birth a year
Limited habitat range
Interference with humans
Organizations that protect species
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Endangered Species Act
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You cannot hunt, kill, trap endangered species
DCNR
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Department of Conservation of Natural Resources