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Evolution- “Change Over Time”

Evolution- “Change Over Time”. All of the changes that have occurred in living things since the beginning of life on Earth. History of the Earth. 700 million years ago…. MULTICELLULAR ORGANISMS!. Three important points…. Evolution occurs over MANY generations

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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. In other words… • Sometimes we see structures in two species that are similar…some of them are: • Homologous (they are similar because of a common ancestor) • Analogous (they are similar because althouth they do NOT share a recent ancestor, they live in similar environments and have adapted to them similarly)

  9. 2 types of Evolution

  10. Evolution Types • Convergent Evolution • Acquiring the same biological trait in unrelated lineages • These traits may be a result of occupying similar environments.

  11. Convergent Evolution

  12. Evolution Types • Divergent Evolution • The accumulation of differences between groups which can lead to the formation of new species, usually a result of different groups of the same species adapting to different environments, leading to natural selection defining the success of specific mutations. h

  13. Divergent Evolution

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

  15. EMBRYOLOGY- suggests common ancestors

  16. 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.

  17. 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

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

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