1. Theory of Evolution “Nothing in biology makes sense EXCEPT in the light of evolution.” - Theodosius Dobzhansky

2. Early Evolutionary Thought  James Hutton Gradualism  Gradual change over time  species formation http://lhs2.lps.org/staff/spu tnam/Biology/ U6Evolution/g radualism.gif

3. Early Evolutionary Thought  Gould and Eldredge Punctuated Equilibrium  A successful species may stay unchanged  Environmental changes cause evolution in spurts http://lhs2.lps.org/staff/spu tnam/Biology/ U6Evolution/g radualism.gif

4. Early Evolutionary Thought  Jean-Baptiste Lamarck Law of Use and Disuse  Understood change over time  Organisms Change Size Or Shape Of Organs By Using Them Or Not  Adaptations are acquired during organism’s lifetime http://www.princesslei a.com/images/MyImage s/essays/giraffe_lamark.jpg

5. Early Evolutionary Thought  Charles Darwin Traveled around the world Galapagos Islands  where he made his Theory of “Descent with Modification”. *Glencoe

6. The Galapagos Islands Darwin studied the animals on islands  Tortoises  Iguanas  Finches *Glencoe

7. Natural Selection  Descent with Modification AKA: “Natural Selection” Organisms best adapted  Most likely to survive  Reproduce & Pass on adaptations to offspring Ex:  Artificial Selection Breeding *Glencoe

8. Evidence of Evolution  Anatomy Homologous Structures  Structural features with a common evolutionary origin *Glencoe

9. Evidence of Evolution  Analogous Structures Similar function but no shared evolutionary origin. *Glencoe

10. Evidence of Evolution  Vestigial Structures Body structure in a present-day organism no longer useful But useful to an ancestor. *Glencoe

11. Evidence of Evolution  Embryology The embryos of a fish, a reptile, a bird, and a mammal have:  A Post anal tail  Pharyngeal gills Suggest evolution from a distant, common ancestor Fish ReptileBirdMammal Pharyngeal pouches Pharyngeal pouches Tail Fish Reptile Pharyngeal pouches Tail *Glencoe

12. Evidence of Evolution  Biochemistry Species with common ancestor more recently have similar hemoglobin (hemo – blood) amino acid sequences.

13. Adaptations  Mimicry Enables one species to resemble another species. Ex. Coral snake which has a powerful neurotoxin that paralyzes the breathing muscles. The common Milk snake is harmless “Red and black, friend to Jack; red and yellow kill a fellow” *Wikipedia

14. Adaptations  Camouflage Adaptation that enables species to blend with their surroundings *Wikipedia

15. Adaptations  Physiological Adaptations Changes in an organism’s metabolic processes Much Faster  Antibiotic Resistance Ex. Antibiotics developed during the twentieth century are no longer effective *Glencoe

16. Speciation New species form  Reproductive Isolation Organisms of the same species no longer breed b/c: Geographic separation Difference in mating periods Genetic differences increase and new species are formed