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Fossils and Evolution of Organic S pecies

Fossils and Evolution of Organic S pecies. What are Fossils?. Any remains or evidence of prehistoric life found in the natural environment. Has to have sufficient antiquity Fossils are older than 10,000 years old. Paleontology. The study of fossils Grouped into two categories Body fossils

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Fossils and Evolution of Organic S pecies

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  1. Fossils and Evolution of Organic Species

  2. What are Fossils? • Any remains or evidence of prehistoric life found in the natural environment. • Has to have sufficient antiquity • Fossils are older than 10,000 years old

  3. Paleontology • The study of fossils • Grouped into two categories • Body fossils • Trace fossils

  4. Body fossils Soft tissue preservation: • Preserved in ice • Insects trapped in amber Hard part preservation, soft tissue destroyed: • Bones, teeth, and shells • Mineral replacement

  5. Mineral replacement • Minerals in ground water eventually takes the place of organic remains • This is called mineralization

  6. Mold/Cast • Mold- fine sediment particles surround organism and preserve the shape of the organism. • Cast when sediments fill in a mold

  7. Can you identify the cast and mold fossils? cast mold mold cast

  8. Trace Fossils • Remains left behind by an animal: • Footprints • Trails • Poop

  9. Life on Earth- how did life begin? • Amino acids were present • Chemical changes, not quite understood, brought about the first forms of life. • Possible theory… Life came from Mars? Evidence of life in Rock fragments from Mars found in Antarctica? • Stromatolites- fossils of clumps of bacteria are recognized as the oldest fossils

  10. Stromatolites:

  11. Organic Evolution • Oldest fossils are primitive tiny single celled organisms- no nucleus. • Complex life forms evolved from the splitting of these organisms. • More complex life forms that could reproduce sexually and inherit characteristics developed 1.4 billion years ago. • Multicellular organisms- jellyfish and worms (1 bya) shells with internal hard parts (454 mya)

  12. Evolution • The gradual change of living organisms from generation to generation • A theory, BUT, one of the most fundamental ideas of science

  13. Four Principals of Organic Evolution: • Variations exist among individuals within a species • Organisms usually produce more offspring then the environment can support. • The effect of competition among individuals of a given generation • The individuals best suited to the environment will live long enough to reproduce and pass their traits to following generations

  14. Variations exist among individuals within a species Differences in: • Size and shape • Abilities to find food • Resist disease • Reproduce

  15. Organisms usually produce more offspring then the environment can support. • An Oak tree produces tons of acorns. If every acorn turned into a tree the world would be covered in oak trees. • Human females produce an egg about every month from the onset of menstruation. If every one was fertilized into a fetus human population would over run the world.

  16. The effect of competition among individuals of a given generation • Organisms most suited to their environment will survive

  17. Natural Selection • The individuals best suited to the environment will live long enough to reproduce and pass their traits to following generations.

  18. Extinction • When all of the individuals of a particular species die. • Most fossils are remains of extinct species.

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