Evolution- “Change Over Time” - PowerPoint PPT Presentation

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Evolution- “Change Over Time” PowerPoint Presentation
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Evolution- “Change Over Time”

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Evolution- “Change Over Time”

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  1. Evolution- “Change Over Time” All of the changes that have occurred in living things since the beginning of life on Earth

  2. History of the Earth

  3. 700 million years ago… MULTICELLULAR ORGANISMS!

  4. Three important points… • Evolution occurs over MANY generations • Evolution occurs within POPULATIONS (NOT individuals) • Evolution involves genetic changes in a SPECIES • (Members of a species interbreed to produce healthy, fertile offspring)

  5. Evidence for Evolution


  6. FOSSIL EVIDENCE-Provides TRANSITIONAL LINKS Archaeopteryx- links reptiles and birds Therapsids- mammal-like reptiles

  7. Anatomical Evidence HOMOLOGOUS STRUCTURES structures that are similar because they were inherited from a COMMON ANCESTOR ANALOGOUS STRUCTURES similar in function, but NOT inherited from a common ancestor NOTE: similar structure, but NOT always function! NOTE: similar FUNCTION, but not STRUCTURE

  8. More Anatomical Evidence:Vestigial Structures Vestigial Structures are undeveloped structures that were functional in some ancestor, but are no longer needed in that organism.

  9. EMBRYOLOGY- suggests common ancestors

  10. BIOGEOGRAPHICAL EVIDENCE • When we study the distribution of plants and animals on the planet, we notice: • Animals evolved differently in each of the biogeographical regions • We see evidence that as the continents drifted, organisms were separated and evolved.

  11. BIOCHEMICAL EVIDENCE • Almost all living things use the same biochemical molecules • DNA, Protein, ATP • Vast diversity came about by only slight differences in the same genes • The more closely “related” the organisms are, the more similar their DNA

  12. Other Evidence… • 1. Mimicry and Camoflauge • 2. Antibiotic Resistance