• Definition of Species Extinction• Type of Extinction• Factor of Extinction• List of Extinct Animal• Solution• Conclusion22
33Definition− Species - can be defined as a group ofindividual organisms that are capable ofinterbreeding to produce fertile offspringin nature.− Species extinction – the permanent loss of aspecies to the planet.Biology and ecology termDefinition− Species - can be defined as a group ofindividual organisms that are capable ofinterbreeding to produce fertile offspringin nature.− Species extinction – the permanent loss of aspecies to the planet.Biology and ecology term
44o It refers to the extinction that occurs naturally in theevolution process.o E.g: climate change, disease or loss of habitatoExtinction of large number of species withinrelatively short period of geological timeoSuch as catastrophic global event or widespreadenvironmental change that occurs too rapidly.o An event in which extinction rates are higher thannormal but not high enough to be classified as a massextinction.
99Example : The Stellers Sea Cow, a marinemammal that was hunted into extinction afew centuries ago. Animals are sometimeshunted for food, but they can also be killedby farmers wishing to protect their crops orby hunters who wish to gain money from ananimals valuable (e.g: pelt, tusks, bones oretc).Overhunting - Any hunting activity that has anadverse impact on the total continuing populationof a species. If sufficient numbers of an animalare killed, their populations can drop to a levelfrom which they cannot recover.
77Invasive species are animals, plants, fungi,microorganism introduced outside of natural habitat-Reproduce rapidly-compete native species for food and habitat-Spread infectious disease to native populationSerious threat to nativeworldwide.e.g Bull frogs-Native to east North America-Transported around for use asfood.-spread infectious disease calleddisease chriodiomycosis
1212Refers to the adoption of new technologies, transition from agriculture-basedto industry-based economy, and general improvement in living standards.What is relationship between economic development and animal extinct?Animal become extinction when their habitats containresources for humans.Example, commercial deforestation in the Amazon Rainforest hasseriously reduced the population of many animal species andlead to the extinction of other groups.
77The density of people is a key factor in species threats. Jeffrey McKee, who is one of the Center ofBiological DiversityWorld’s human population doubledfrom 1 to 2 billion between 1800 and1930. At the end of October 2011, itexceed 7 billion population.Now, the world already witnessed thedevastating effects of overpopulation. InNorth America, Mountain grasshopperand parrot have been wiped out bygrowing human number.
1313Today human population 7 bilion2020 human population 8 bilion2050 human population 9 bilion1804 human population 1 billion1990 human population 5.3 billionAs population growth, demand for water, land,trees and fossils fuel also increaseExplosiveunsustainablehuman populationcrisis
99rain forest dries upcool mountains in tropical zones heat upOur climate changes both naturally and due to human exploitationPollution :Human release carbon dioxide, chemicals, andgreenhouse gasses into atmosphereAnimal go extinct not able to adapt to the drastic climate changeE.g•Golden toad•Sea turtle•Orang utan
1616The Tasmanian tiger-wolf becameextinct on the mainland of Australialong ago because it could notcompete for food with an introducedspecies, the dingo, a kind of wild dog.Tasmanian tiger-wolves continuedto thrive on the dingo-free island ofTasmania off Australias south coastuntil Europeans arrived in the region.An unknown disease decimated theremaining population in 1910. By 1933 itwas believed that the species had becomeextinct in the wild. In 1936, the last knownTasmanian tiger-wolf died in captivity.
1616The dodo bird inhabited the island ofMauritius in the Indian Ocean, where it livedundisturbed for so long that it lost its needand ability to fly. It lived and nested on theground and ate fruits that had fallen fromtrees. There were no mammals on the islandand a high diversity of bird species lived inthe dense forests.In 1505, the Portuguese became the firsthumans to set foot on Mauritius. The islandquickly became a stopover for shipsengaged in the spice trade. Weighing up to50 pounds, the dodo bird was a welcomesource of fresh meat for the sailors. Largenumbers of dodo birds were killed for food.The last dodo bird was killed in 1681.
2020The golden toad was last seen in 1989 in the Costa Rican cloud forest ofMonteverde—and 5 years later, its disappearance was the first extinction tobe blamed on humanmade global warming. New evidence, however,suggests that humans may not have been at fault after all.The current line on what drove the golden toad extinct. As humans pumpedcarbon dioxide and other greenhouse gases into the atmosphere, CostaRican rainforests became hotter and dryer in the mid-1980s. Theseconditions made the toad vulnerable to the chytrid fungus, which isthought to thrive in warmer, drier climes.
2222 Nature reservedPreserved & protect species habitat Captive breedingBring into captivity and breed the species ReestablishmentRelease of a species into the wild Laws and regulationsSpecies & biological diversity are protected by law International agreementNeed to protect biodiversity . CITES Nature reservedPreserved & protect species habitat Captive breedingBring into captivity and breed the species ReestablishmentRelease of a species into the wild Laws and regulationsSpecies & biological diversity are protected by law International agreementNeed to protect biodiversity . CITES
2323Today extinction rate ~ 1000 and 10,000 times higherthan the natural extinction ratePollution is not the only factor threatening wildlifeResearchers concluded that if climate warmingproceeds unchecked, 15% to 37% of the 1103 plant andanimal species they examined will disappear by 2050Extinction & disappearance of amphibians worldwideat rates much higher than normal, is an indication thathuman activity is taking a toll on ecosystemsworldwide.