Topic 4 Slides - Cross.pptx

REDUCTION OF BIODIVERSITY Topic 4 Dear Future Generations 6 min EXTINCTION • The disappearance of every individual of a species from the entire planet • Scientists estimate that 99% of all species that have ever existed are now extinct • Some species are brought to extinction through catastroph...

REDUCTION OF BIODIVERSITY Topic 4 Dear Future Generations 6 min EXTINCTION • The disappearance of every individual of a species from the entire planet • Scientists estimate that 99% of all species that have ever existed are now extinct • Some species are brought to extinction through catastrophic events which happens quickly and others occur slowly through human interaction • Example: Dinosaurs CLASSIFICATIONS • There are 4 classifications that we use to describe species that humans are concerned about • Extirpated • Endangered • Threatened • Special Concern (Vulnerable) EXTIRPATION • A local disappearance of a species from a particular area • Example: Grizzly Bear (used to be found all the way in Manitoba) • Example: Swift Fox used to be common in Canada but by 1928 it was extirpated from Canada ENDANGERED • Species that are in immediate danger of extinction or extirpation • Example: The Burrowing Owl, Leatherback Turtles THREATENED • Species that are likely to become endangered if changes are not made • Example: Wood Bison SPECIAL CONCERN (VULNERABLE) • Species that are particularly vulnerable to natural events or human activities • Ex. Northern Leopard Frog NATURAL CAUSES OF EXTINCTION AND EXTIRPATION • Natural selection usually occurs in a slow process, but if the environment of a species changes too quickly or too drastically a species may not survive. • Some possible causes: • Catastrophic Events (flood, fire, volcanic eruptions) • Lack of food due to overpopulation • Disease HUMAN CAUSES OF EXTINCTION AND EXTIRPATIONS Today, most extinctions and extirpations are due to: • Habitat Destruction • Introduction of Non-Native Species • Over-Hunting • Human Activity HABITAT DESTRUCTION • Construction of buildings, agricultural development, logging • Damming of rivers changes the environment. • Pollution is also included in habitat destruction. ex. pesticides, herbicides and fertilizers OVERSPECIALIZATION • Sometimes organisms have adaptations that suit them to only a narrow set of environmental conditions. • Example: Panda’s only eat Bamboo. It cannot switch to another source of food. So, if the forests were destroyed the Panda would become extinct. INTRODUCTION OF NON-NATIVE SPECIES • Throughout our history, migrating humans have both knowingly and unknowingly carried non-native species with them. • These species will compete with the native species over niches. • Example: Zebra Mussels, Thistles and Dandelions. OVER-HUNTING • unsustainable hunting; hunting to excess • Ex. Plains Bison: the meat, bones, and the hide were all used for survival. • Ex. African Elephant: JUST THE TUSKS :( EFFECTS OF EXTINCTION AND EXTIRPATION • Reduce amount biological diversity • Reduce the total number of species ** It can also affect many other species, such as those that rely on them as a food source Reducing Our Impact on Biological Diversity ❧ Please have your notes out and add what you may have missed Five Strategies Used to Preserve Species ❧ Diversity ❧ Protected Areas ❧ Restoration of Ecosystems and Species ❧ Resource Use Policies ❧ Controlling the Spread of Exotic Species ❧ Conservation of Genetic Resources 1. Protected Areas ❧ In-situ Conservation: Maintenance of organisms in their natural environment ❧ Ex. National and provincial parks, ecological preserves 2. Restoration of Ecosystems and Species ❧ ❧ Charities, non-profit organizations, volunteer groups and landowners contribute to restoring species and natural habitats by giving land and revitalizing habitats 3. Resource Use Policies ❧ ❧ Federal and provincial government laws that help species that are endangered 4. Controlling the Spread of Exotic Species (Non-Native) ❧ ❧ Federal, provincial and municipal governments work to develop policies to stop the spread of exotic species. 5. Conservation of Genetic Resources ❧ Ex-situ Conservation ❧ maintenance of organisms outside of their natural habitats ❧ Endangered species maintained in a zoo ❧ Seed banks can help maintain species of plants Top 10 Almost Extinct Animal s ❧ Zoos or National Parks ❧ Task: Pros and Cons of National Parks and Zoos You must identify 2 pros and 2 cons for each category. Pros and Cons of Zoos ❧ 5 min History of National Parks ❧ 4 mins SELECTING DESIRABLE TRAITS 3 min Natural Selection vs Artificial Selection Artificial Selection • Selectively breeding plants and animals with desirable traits to produce offspring with those desirable traits • Since the beginning of farming humans have practiced artificial selection. • What is the difference between artificial selection and natural selection? Risks in Animals • Most individuals in livestock population are extremely similar as a result of artificial selection • Problem: A species that are genetically identical are more likely to get diseases • What impacts does this have on DNA? Risks in Plants • All modern day crops were produced by artificial selection of wild plants • Genetic engineering has altered DNA to make crops resistant to herbicide, so that the crops can be sprayed and only the weeds die • Problem: Crop plants can still cross with their wild weed relatives and offspring have become resistant to herbicide. GMO = Genetically Modified Organism 9 min Biotechnology • Using living organisms to make agricultural, industrial or medicinal products. • Farmers and ranchers began using biotechnology many years ago to improve their crops and herds. $$ • It takes many generations to successfully get an organism with desired traits Evolution of Biotechnology • 12 min Genetic Engineering • Refers to any technology that directly alters the DNA of an organism • This usually consists of inserting a desirable gene from one species into another Example: Genetically modified bacteria now produce insulin because of a gene inserted into them. Diabetics need insulin and since bacteria grow so quickly they can produce a lot of insulin which allows it to be sold cheaply Artificial Reproductive Technology • It is any artificial method of joining male and female gametes • Most cows in Canada are produced this way • Artificial insemination is when sperm are taken from a bull with the desired traits and the sperm is inserted into the female cow Creating Plant Clones • Originally horticulturalists “cloned” a plant by taking a cutting off of it and growing an identical version of it • Today scientists can clone faster by taking a cell from an individual plant with desirable traits and place it in a petri dish where they can grow into seedlings. A lot more seedlings can be grown through cloning a cell than through cuttings Cloning in Animals • Scientists are able to produce an identical copy of an individual animal • The most famous example is a sheep named Dolly who is genetically identical to her mother. • Cloning is still in its early stages • Many trials have reported unsuccessful pregnancies, birth defects, and death of clones. 5 min Dolly Genetically Altering Humans • As science continues to progress, we have also developed several methods to alter the genetic composition of human babies • Using these methods we can eliminate certain genetic diseases and select favourable physical traits • This is still highly controversial Designer Babies • 5 min