animal extinction

Click here to load reader

Upload: andrew12intry

Post on 30-Jun-2015

540 views

Category:

Documents


1 download

TRANSCRIPT

  • 1. Animal Extinction Andrs Intriago Mishell Ruiz Rafael Chacn

2. Extinction is one of the major features ofevolution. A species is extinct when no membersof the species are still alive. All species become extinct sooner or later. Theend of a species may happen for many reasons.It may be caused by habitat loss or by beingoverhunted, or by a major extinction event. Anexample of an animal that is now extinct is theDodo, from over-hunting. A species that is endangered has a good chanceof becoming extinct. Fossil species sometimesreappear millions of years after they were thoughtto be extinct. These cases are called Lazarustaxa. 3. Duration of species The average duration of species varies according to the groups studied. A study of benthic (deep water) foraminifera showed an average of 16 million years if they lived above 200 metres, but 25my if they lived below 200 metres.[2] On the other hand, the average survival time for mammalian species over the past 20my has been 2.33my. 4. Duration of higher groups Naturally, higher categories such as genera, families, orders, classes and phyla last longer, because they are composed of more species. As far as we know, no phylum has gone completely extinct since the Cambrian, but quite a few classes went extinct in one or other of the big five extinction events. Examples of higher categories of animal now extinct are: placoderm fish, trilobites, ammonites, pelycosaurs, dinosaurs, pterosaurs, ichthyosaurs, plesiosaurs... 5. Reasons Darwin thought that most extinctions occurred because some organisms became more effective, and replaced their less advanced competitors. No doubt that does occur. But now we put more emphasis on environmental changes. Organisms become adapted to the environments they live it. The environment certainly does change, and sometimes quite dramatically. When it does, some organisms can adapt to the changes, and some cannot. The ones that cannot become extinct. That is all there is to it. 6. Galapagos Animals The Galapagos animals are perhaps the most famous attractions of this archipelago. The animals of the Galapagos Island are most notable for their uniqueness and their proximity to visitors. Visitors can literally swim and hike right alongside some of the worlds most unique species, as they exist in their natural habitat. Some of the most popular endemic Galapagos animals are close to extinction, and their protection is of high priority. As such, it is best to observe the rules surrounding a visit to the Galapagos Islands to ensure the safety of Galapagos animals for years to come. 7. The Galapagos Tortoise 8. The Waved Albatross 9. Penguins 10. The Marine Iguanas 11. The Cormorant 12. The Marine Turtle 13. Animals in danger of extinction inEcuador Spectacled Bear. 14. Monkey CHORONGO 15. Tapirus terrestris 16. The Condor 17. Mountain Lion