Extinction.pdf

Biodiversity Loss Extinction of Species - last member or individual is lost forever Loss of Specific Habitat - What do you think will happen if habitats will disappear? Loss of Genetic Variations within Species - Genetic variation is related to species survival and adaptati...

Biodiversity Loss Extinction of Species - last member or individual is lost forever Loss of Specific Habitat - What do you think will happen if habitats will disappear? Loss of Genetic Variations within Species - Genetic variation is related to species survival and adaptation BIODIVERSITY LOSS:  Extinction is forever!! When is a species considered extinct? –If no members of that species are still alive. –Most organisms that have ever lived on Earth are now extinct. EXTINCT ANIMALS IN THE PHILIPPINES: The Philippine elephant (Elephas beyeri), also known as the Philippine dwarf elephant, the Philippine pygmy elephant, the Luzon elephant, the Luzon dwarf elephant, and the Luzon pygmy elephant, is a species of dwarf elephant belonging to the Elephantidae family that originally lived on Cabarruyan Island, Visayas.  The Visayan warty pig (Sus cebifrons) is a critically endangered species in the pig genus (Sus). It is endemic to six of the Visayan Islands (Cebu, Negros, Panay, Mas bate, Guimaras, and Siquijor) in the central Philippines. It is known by many names in the region (depending on the island and linguistic group) with most translating into 'wild pig':  Siebenrockiella leytensis is a species of freshwater turtle endemic to the Philippines. It is classified as critically endangered. It is known as the Philippine forest turtle, the Philippine pond turtle, the Palawan turtle, or the Leyte pond turtle. Background or Natural Extinction Normal or natural extinction Standard rate of extinction before humans entered the picture. Mass or Accelerated Extinction Sudden extinctions (confined to a few million years or less) which sweep away a large variety of living creatures. Primarily caused by human activities. Factors that contribute to extinction Natural factors – Have caused extinctions throughout history. Man-made factors (Anthropogenic) – Have caused extinction in more recent times. Brainstorm potential examples of each type. Natural Factors Man-made Factors Natural Factors Organisms could not survive changes due to various natural events. Natural extinctions have occurred throughout geologic history. Not all extinctions have a negative impact. – They clear the way for new kinds of life. Natural Factors of Extinction Volcanic Activity – Huge lava flows that produced enormous amounts of ash. – The ash in the air altered the global climate and ocean chemistry. Natural Factors of Extinction: EXTREME HEATING AND COOLING OF EARTH Global Warming – Animals could not survive the extreme change in temperatures and climate. – Diseases and epidemics Global Cooling (Ice Ages) – Cooling events caused Glaciation events – Ocean water would freeze and therefore lower the sea level. Natural Factors of Extinction Changes in Landscape – As water cools, it causes dramatic shifts in limiting factors such as oxygen (oxygen depletion) – As oxygen levels in sea water were depleted, many species died out. – Diseases and epidemics Acid Precipitation - Changes in the chemical composition of soil and water make them unsuitable for different life forms. Natural Factors of Extinction Asteroid or comet impact – The impact from a huge asteroid would have sent tidal waves across the earth and caused many fires. – Clouds of dust and ash would block the sunlight. The planet would cool and plants and animals would die due to lack of sunlight. – The impact that killed the Dinosaurs was thought to have occurred in somewhere near Mexico. Chalk Talk Review of natural factors of extinction. Man-made Factors of Extinction Many plants and animals are likely to become extinct in the near future. Humans remove survival needs of many organisms. We are also threatening our own biological resources. Man-made factors are damaging the Earth. Man-made Factors of Extinction Cutting of rainforests – Destroys habitats and food sources of many different animals. – Trees are logged for human needs. Man-made Factors of Extinction Removing of Natural Habitats – Cutting down rainforests, agricultural activities and houses for humans. – Animals have no where to live, breed and hunt. Man-made Factors of Extinction Over-harvesting or Hunting – Many animals have been hunted to extinction by humans due to various socio-economic factors. – Example, the Carolina Parakeet. Lived in the southeastern United States. Appeared 5 million years ago and became extinct in the early 1920’s from hunting. Man-made Factors of Extinction Pollution – Industrial activities have polluted rivers and oceans with toxic chemicals. – Acid rain, bioaccumulation and biomagnification – Eutrophication Man-made Factors of Extinction Introduction of foreign species – Sailors would bring domesticated animals to remote areas. (dogs, rats……) – These animals would kill native animals and compete for food sources. – They can upset ecological balance. Chalk Talk Review of man-made factors of extinction. Activity Time! Endangered Species Mini-Poster a. The name of the species. b. A description of why it became endangered. c. An explanation of its importance in the ecosystem. d. A picture, drawing, or diagram of the organism.