Threatened and Endangered, and Extinct Species

Biodiversity Extinction – the process by which an organism is no longer in existence as a species Extinct organisms Dinosaur Woolly Mammoth Saber tooth Dodo bird Passenger pigeon

Causes of Extinction Ice Age Meteors Predators Poaching Hunting Habitat Loss

Why are organisms so important? Food Chain Food Medicine Protection

Biodiversity The different types of life (streams, wetlands) Diagram of PA Biodiversity

Biodiversity is studied on three levels Genetic – biodiversity is the difference between genes of a particular species Species – grey squirrel vs. Delmarva Fox squirrel Ecosystem – biodiversity – stream vs. wetland

Variations Differences in the phenotype of a species Appearance Height Width Weight Allow for adaptation to new environments

Organism Niches Role an organism plays; two organisms cannot occupy the same niche

Predator-Prey Relationships Mice vs. Weasel

Predators Clean up the weak or sick Help out to remove the weak organisms

Symbiosis Two organisms rely on each other for survival

Parasitism One organism benefits while the other is harmed Human and tapeworm

Mutualism Both organisms benefit Rhino and birds

Commensalism One organism benefits, other is unharmed Birds nest and tree

Adaptations Adaptation – special modifications or characteristics that help an organism better survive its environment

Structural Adaptation Body parts, internal/external, thumbs, tails, claws, color, fur, beak Mimicry – another organism acts like the first (structural or behavioral) Camouflage – blend in with your environment

Behavioral Adaptation How an organism acts Cat bird Lions carrying young Reflexive behavior – caught by surprise Cat Snake recoils Instinctive behavior – you don’t have to be taught Mother, baby

Survival of the Fittest 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 Traits must vary Adaptations must be genetic Adaptation must be beneficial for survival

Human impacts Negative – destroy lands Positive Endangered – population increases Capture breeding – zoos Treat injured organisms

Threatened, Endangered, Extinct 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 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 Endangered Species Act You cannot hunt, kill, trap endangered species DCNR Department of Conservation of Natural Resources