1. Darwin and Evolution Evidence Adaptation Speciation

2. Darwin’s Voyage H.M.S. Beagle (1831) – as the ship’s naturalist collected plant and animal specimens collected fossils some resembled organisms still alive some were completely unknown

3. Darwin’s Voyage Galapagos Islands (west of South America) found giant land tortoises, marine iguanas and finches with differently shaped beaks

4. Darwin’s Voyage Returned to England in 1836 discovered that the organisms found on the Galapagos were found nowhere else BUT, each species looked like similar species found on the mainland 1859 he published On the Origin of Species Proposed the idea of natural selection struggle for existence survival of the fittest – live to reproduce

5. Ideas That Influenced Darwin James Hutton – proposed that Earth is shaped by geological forces that took place over extremely long periods of time Charles Lyell – explained that processes occurring now have shaped Earth’s geological features over long periods of time

6. Ideas That Influenced Darwin Jean-Baptiste Lamark – proposed that by selective use or disuse of organs, organisms acquired or lost certain traits during their lifetime These traits could be passed on to their offspring Alfred Wallace – wrote to Darwin, speculated about evolution by natural selection based on his studies of plants and animals

7. Darwin’s Theory Variations exist in a population and are inherited In nature, there is a tendency toward overproduction Species compete for limited resources Each individual has advantages and disadvantages

8. Darwin’s Theory Individuals best suited to the environment survive and reproduce; those not as well suited die or have fewer offspring Species change over time – new species appear and others disappear Descent with modification Common descent

9. Evidence for Evolution Anatomy Embryology Biochemistry Genetics

10. Anatomy comparative anatomy – study of structures of different organisms vestigial organs – structures that have no function in the living organism (appendix) homologous parts – similar body parts

11. Embryology and Biochemistry comparative embryology – study of developing organisms embryos start out very similar, but as they develop, they become distinct comparative biochemistry – studies of organisms on a biochemical level (proteins, DNA)

12. Genetics production of new alleles and genetic recombination mutations selective breeding DNA of humans and chimps is 99% identical

13. Adaptation Structural Physiological Behavioral

14. What is an adaptation? Any trait that aids the chances of survival and reproduction of organisms Variations vs. Adaptations Adaptations are products of evolution by natural selection (always good) Variations are the raw materials upon which natural selection acts (can be good or bad)

15. Complex adaptations e.g. the eye Does not arise overnight Occurs over many, many generations Does not invent, but modifies what already exists

16. Types of adaptations Structural adaptations – adaptations involving structure or anatomy (woodpecker’s beak, anteater’s snout) Physiological adaptations – adaptations with a chemical basis that is associated with an organism’s function (spider’s web, snake venom) Behavioral adaptations – results from the response of an organism to its environment (bird’s migrating, plants growing to light)

17. Human Evolution Homo habilis Homo erectus Homo sapien

18. Primate adaptations Humans are primates (so are monkeys and apes) Problem-solving ability Flexible shoulders and forelimbs that can be rotated Opposable thumb

19. African origins Australopithecines – “southern ape” Lucy – 3.5 million years old 3-4’ tall and about 66 pounds If she were alive today, she would not be considered human

20. Origin of Humans Hominids – modern humans Handy man (Homo habilis) – 1.8 million yrs ago – made tools Upright man (Homo erectus) – 1 million yrs ago – learned to make and use fire Modern man (Homo sapien) Neanderthals – short, powerfully built Cro-magnons – fully modern height, skull structure, skeleton, teeth and brain size