Chapter Three S ection T hree

1. Chapter Three Section Three Biodiversity and Extinction

2. Introduction There is no exact number of how many species are on earth but there have been about 1.5 identified. Biodiversity is the number of different species in an area.

3. What do these two pictures have to do with biodiversity?

4. There are still organisms that are yet to be discovered!!!! • Think of all the areas that humans have a hard time getting to. • Deep ocean • Tropical rainforest • Deep within the earth’s crust

5. The Value of Biodiversity • There are three main reasons to preserve biodiversity: • Source of beauty and recreation • Economic value • Ecological value

6. Economic Value Many plants and animals are economically valuable for humans.

7. Economic Value • What do plants and animals give humans: • Food • Clothing • Medicine • Other products as well

8. Economical Value • The ecosystems in which the organisms live are also valuable. • Ecotourism is an important source of jobs and money.

9. Ecological Value • We know from past units that all organisms in an ecosystem are connected to one another. • Organisms depend on one another for food and shelter. • When there is a change that affects one organism it is going to affect others.

10. Ecological Value A keystone species is a species that influences the survival of many other species.

11. Ecological Value http://www.youtube.com/watch?v=cKB5cI7geCg- Keystone species the honey bee

12. Factors Affecting Biodiversity • Factors that affect biodiversity are: • Area • Climate • Diversity of niches

13. Area Within an area a large area would contain more species of organisms than that of a smaller area.

14. Climate The number of species increase from the poles to the equator

15. Climate • The ecosystems of Latin America, Southeast Asia, and Central Africa are the most diverse in the world. • Covers about 7% of the worlds land mass but contains about 50% of the worlds plants and animals. • Coral Reefs are another example they make up less than 1% of the ocean but contain about 20% of the worlds fish.

16. Niche Diversity Coral reefs are the second most diverse ecosystem in the world. A coral reef supports many different niches of an organism. It allows many different species to live in the reef than in a ecosystem that would support all similar organims.

17. Gene Pool Diversity • Organisms in a healthy population have a number of different traits. • These traits are determined by the organisms genes. • Genes are the structures in its cells that carry its hereditary information • Found in the nucleus of every single cell in your body!!!!!

19. Gene Pool Diversity Species that lack a diverse gene pool are less able to adapt in order to survive. Species that have a diverse gene pool are more able to adapt in order to survive.

20. Extinction of Species The disappearance of all organisms from earth is called Extinction

21. Extinction of species Species in danger of becoming extinct is called endangered species

22. Extinction of Species Species that could become endangered in the near future are called threatened species

23. Causes of Extinction • There are four major causes of extinction: • Habitat destruction • Poaching • Pollution • Exotic species

24. Habitat Destruction The largest cause of extinction of species is habitat destruction or the loss of a natural habitat

25. Poaching The Illegal killing or removing animals from their natural habitat is called poaching. Many endangered or threatened animals are hunted for their teeth, horns, skin, and fur.

27. Pollution Some species are endangered because of pollution. The pollutants affect the animal’s water they drink and the air the breath.

28. Exotic Species Introducing exotic species into an ecosystem can threaten biodiversity. http://www.youtube.com/watch?v=R2kV5uXLLu4 invasive species

29. Protecting Biodiversity • There are three successful approaches to protecting biodiversity. • Captive breeding • Laws and treaties • Habitat preservation

30. Captive Breeding Captive breeding is the mating of young animals in zoos or animals preserves

31. Laws and Treaties • The most important treaty protecting wildlife is the Convention of International Trade in Endangered Animals. • More than 800 endangered or threatened animals cannot be traded for profit

32. Habitat Preservation The most effective way to preserve biodiversity is to protect the whole ecosystem in which the organisms are found.

33. Chapter 4 Section One Fossils

34. Introduction Fossils are the preserved remains or traces of living things

35. How a Fossil Forms Most fossils form when living things die and are buried by sediments. The sediments slowly harden into rocks and preserve the shapes of the organisms

36. How a Fossil Forms Fossils are normally found in sedimentary rock. Sedimentary Rock- is the type of rock that is made of hardened sediment

37. How a Fossil Forms • Sedimentary rock is made of rock particles and the remains of living things. • Examples: • Coal • Sandstone • Limestone • http://www.brainpop.com/science/diversityoflife/fossils/

38. How a Fossil Forms An animal dies and sinks into shallow water Sediment covers the animal The sediment becomes rock, (only the hard parts of the animals) preserving parts of the animal Weathering and erosion eventually expose the fossil at the surface.

39. How a Fossil Forms Fossils found in rock include molds and casts, petrified fossils, carbon films and trace fossils Other fossils form when the remains of organisms are preserved in substances such as tar, amber, or ice.

40. Molds and Casts • Fossils fall into the following categories: • Mold • Cast • Petrified • Carbon films • Trace fossil • Preserved remains

41. Mold and Cast • Mold is a hallow area in sediments in the shape of an organism or part of an organism • Cast is a solid copy of the shape of an organism • Opposite of the mold • Both preserve details of the animals structure

43. Petrified Fossil • The term petrified means turned to stone • Petrified Fossils are fossils in which minerals replace all or part of an organism • Overtime minerals fill in all the spaces and harden to preserve the fossil

45. Carbon Films • Carbon film an extremely thin coating of carbon on rock • This type of fossil preserves the delicate parts of plant leaves and insects

46. Trace Fossils • Trace Fossils provide evidence of the activities of ancient organisms • Example: • Dinosaur footprint

47. Trace Fossils From fossil footprints, scientists can find answers to questions about an animals size and behavior. Other trace fossils give evidence about where the organism lived or how it obtained its food

48. Preserved Remains • There are some fossils that preserve the organism with little or no change • They can be preserved in: • Tar • Amber • Freezing