Evolution by Natural Selection

1. Evolutionby Natural Selection Objectives 9/9/11 Go over open ended response for Darwin and Test Results – practice outlining correctly. Begin evolution and diversity of organisms unit. Website Issue: NO www before it. Just type rossman.educatorpages.com Extension on bonus question. Survival of the sneakiest Comic to review concepts. Upcoming Due Dates: AP flashcard vocab due Monday. Writing assignments due Monday. Open Ended Question Fixed for Monday.

2. DOCTRINE TINTORETTO The Creation of the Animals 1550

3. But the Fossil record… OBSERVATION

4. mya 1.5 Plants Birds 63 Mammals 135 Reptiles Seed Plants Flowering Amphibians Insects Dinosaurs 180 Teleost Fish Land Plants Jawless Fish 225 Chordates Molluscs Arthropods 280 Multicellular Animals Green Algae 350 Photosynthetic Bacteria Anaerobic Bacteria 400 430 500 570 700 4500 Life’s Natural History is a record of Successions & Extinctions

5. Initial Time Line Assignment • Earth was formed approximately 4.5 billion years ago.

6. LaMarck • Organisms adapted to their environments by acquiring traits • change in their life time • Disuseorganisms lost parts because they did not use them — like the missing eyes & digestive system of the tapeworm • Perfection with Use & Needthe constant use of an organ leads that organ to increase in size — like the muscles of a blacksmith or the large ears of a night-flying bat • transmit acquired characteristics to next generation

7. Charles Darwin • 1809-1882 • British naturalist • Proposed the idea of evolution by natural selection • Collected clear evidence to support his ideas

8. Voyage of the HMS Beagle • Invited to travel around the world • 1831-1836 (22 years old!) • makes many observations of nature • main mission of the Beagle was to chart South American coastline Robert Fitzroy

9. Darwin did NOT challenge the existence of a divine creator • He thought the divine creator was present and “expressing himself”

10. Voyage of the HMS Beagle • Stopped in Galapagos Islands • 500 miles off coast of Ecuador

11. What did he do with his down time? • Read Charles Lyell. Contemplated the theory of animals and plants in flux as continents change. • Studied the plants and animals of different areas. Saw related but distinct life on islands.

12. Glyptodont fossils are also unique to South America. Succession of types Armadillos are native to the Americas, with most species found in South America. Why should extinct armadillo-like species& living armadillos be found on the samecontinent?

13. Modern sloth (right) Mylodon (left) Giant ground sloth (extinct) “This wonderful relationship in the same continent between the dead and the living will…throw more light on the appearance of organic beings on our earth, and their disappearance from it, than any other class of facts.”

14. Unique species

15. Finch? Sparrow? Warbler? Woodpecker? Darwin found… birds Collected many different birds on the Galapagos Islands. Finch? Sparrow? Thought he found very different kinds… Warbler? Woodpecker?

16. But Darwin found… a lot of finches Darwin was amazed to find out: All 14 species of birds were finches… But there is only one species of finch on the mainland! Large Ground Finch Small Ground Finch Finch? Sparrow? How didone species of finches becomeso many differentspecies now? Warbler Finch Veg. Tree Finch Warbler? Woodpecker?

17. Tree Thinking Descendantspecies Ancestralspecies Large-seed eater? Large GroundFinch Small-seed eater? Small GroundFinch Warbler? Leaf-browser? Veg. Tree Finch Warbler Finch

18. Correlation of species to food source Seedeaters Flowereaters Insecteaters Rapid speciation:new species filling new niches,because they inheritedsuccessful adaptations. Adaptive radiation

19. Darwin’s finches • Differences in beaks • associated with eating different foods • survival & reproduction of beneficial adaptations to foods available on islands Warbler finch Cactus finch Woodpecker finch Sharp-beaked finch Small insectivorous tree finch Small ground finch Warbler finch Large insectivorous tree finch Cactus eater Mediumground finch Tree finches Ground finches Insect eaters Seed eaters Vegetarian tree finch Large ground finch Bud eater

20. Darwin’s finches • Darwin’s conclusions • small populations of original South American finches landed on islands • variation in beaks enabled individuals to gather food successfully in the different environments • over many generations, the populations of finches changed anatomically & behaviorally • accumulation of advantageous traits in population • emergence of different species

21. Seeing this gradation & diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species has been taken & modified for different ends.

22. Darwin’s finches • Differences in beaks allowed some finches to… • successfully compete • successfully feed • successfully reproduce • pass successful traits onto their offspring

23. Correlation of species to food source More observations… Whoa,Turtles, too!

24. Many islands also show distinct local variations in tortoise morphology… …perhaps these are the first steps in the splitting of one speciesinto several?

25. Artificial selection This is not just a process of the past… It is all around us today