Evolution

1. Evolution The Origin of Life http://www.youtube.com/watch?v=h1BQPV-iCkU&feature=related

2. Key Concepts • Origins of life • Evolutionary processes • Species formation • Species extinction • Classification of Species http://img135.imageshack.us/img135/7858/liger13zi.jpg

3. One day the zoo-keeper noticed that the orangutan was reading two books - the Bible and Darwin's The Origin of Species. In surprise he asked the ape, "Why are you reading both those books"?"Well," said the orangutan, "I just wanted to know if I was my brother's keeper or my keeper's brother."

4. Charles Darwin and the Voyage of the Beagle. • Born in 1809 (same year as Lamark presented his theories of evolution) • In 1831, travelled around the world as a naturalist on the ship called the Beagle • Made observations that organisms seemed really well adapted to their particular environments. • All his work is based on those observations.

5. Darwin’s Observations • Patterns of Diversity • So many different, but very similar organisms • All appear well adapted to their environments • Similar environments, but different organisms • Living Organisms and Fossils • Recognized that many living organisms resemble fossils of extinct organisms • The Galapagos Islands • 3000 miles off the coast of Ecuador • Geographic isolation • Organisms on each island were similar, but different and seemed well adapted to their particular environment.

8. “Evolution” of Darwin’s Theories • Beliefs of the time-period (1800’s) • God made everything in the current form • Earth was as old as the Bible said it was – about 3000 years old. • Darwin believed it had to be older than that. • James Hutton (1795) was a geologist that stated the earth was much older than 3000 years. • Based on rock evidence (specifically how rocks were folded and not level) he theorized that it took millions of years to do, not thousands.

9. 1800 Napoleon conquers Italy,Alessandro Volta produces electricity. 1803 U.S. negotiatesLouisiana Purchasefrom France: for $15 million 1804 Lewis and Clark expeditionbegins exploration of what is now northwest U.S. 1808 Congress bars importation of slaves. Beethoven'sFifthandSixth Symphoniesperformed. 1809 Charles Darwin born 1814 Napoleon exiled to Elba, off Italian coast. 1823 U.S.Monroe Doctrinewarns European nations not to interfere in Western Hemisphere. 1824 Mexico becomes a republic, three years after declaring independence from Spain. 1825 First passenger-carryingrailroadin England. 1826 Joseph-Nicéphore Niepce takes the world's firstphotograph. 1830 Church of Jesus Christ of Latter-day Saintsformed in U.S. by Joseph Smith. 1833 Slavery abolished in British Empire. 1846 U.S. declares war on Mexico.Frederick Douglasslaunches abolitionist newspaperThe North Star. 1846 potato crop causes famine in Ireland. 1848 Harriet Tubman escapes from slavery and joins theUnderground Railroad. 1849 California gold rush begins. 1857 Supreme Court, inDred Scottdecision, rules that a slave is not a citizen 1858 Pro-slavery constitution rejected in Kansas.Abraham Lincolnmakes strong antislavery speech in Springfield, Ill.: “This Government cannot endure permanently half slave and half free.” 1859Charles Darwin'sOrigin of Species. 1861 U.S. Civil Warbegins as attempts at compromise fail. Mississippi, Florida, Alabama, Georgia, Louisiana, and Texas secede; with South Carolina, they form the Confederate States of America, with Jefferson Davis as president. Virginia, Arkansas, Tennessee, North Carolina secede and join Confederacy. Lincoln inaugurated. 1862 Several major Civil War battles: Battle of Shiloh, Second Battle of Bull Run (Manassas), Battle of Antietam. 1863 Battle of Gettysburg. 1865 Civil War is over. Lincoln fatally shot at Ford's Theater byJohn Wilkes Booth.Gregor Mendel'sLaw of Heredity.Lewis Carroll'sAlice's Adventures in Wonderland. 1866 Alfred Nobelinvents dynamite (patented in Britain,1867). 1868 Fourteenth Amendmentgiving civil rights to blacks is ratified. 1871 The Chicago Fire, with 250 deaths and $196-million damage. 1876 Alexander Graham Bellpatents the telephone. 1879 Thomas A. Edison invents practical electric light. 1885 World's first skyscraper built in Chicago. 1888 George Eastman's box camera (the Kodak). Jack the Ripper murders in London. 1889 Eiffel Tower built for the Paris exposition. 1893 New Zealand becomes first country in the world to grant women the vote. 1895 X-rays discovered by German physicist Wilhelm Roentgen.

10. “Evolution” of Darwin’s Theories • Charles Lyell (1833) supported Hutton’s earlier theories and further explained that geologic process that occur now are occurring the same way as they did in the past (and that scientists must be able to explain this based on what they actually observe) • On the Galapagos Islands, Darwin actually observed an earthquake that shifted the shoreline up and out of the water, exposing marine organisms.

11. “Evolution” of Darwin’s Theories • Jean-Batiste Lamark(1809) published his theory of evolution. • Tendency towards perfection • Use and Disuse • Inheritance of acquired traits • Although good theories that helped to shape Darwin’s theory of evolution, they were later proven to be wrong

12. Lamark Giraffe’s Neck (tendency towards perfection) Arnold Schwarzenegger (use or disuse) Tattoos (acquired traits)

13. “Evolution” of Darwin’s Theories • Thomas Malthus (1798), an economist predicted that human populations would outgrow its resources and die. • Darwin believed that this could apply to all organisms. • It meant that something (not known yet) was controlling birth rate and death rate of all organisms. • Why do some organisms survive?

14. The Origin of Species • In 1859, Darwin published The Origin of Species. • It is this book that has caused so much controversy… even today. • Natural Selection • Inherited vs. Artificial Selection http://www.npr.org/templates/story/story.php?storyId=4630737

15. Evolution by Natural Selection • Struggle to survive • Competition of resources (remember the competitive exclusion principle?) • Organisms struggle to maintain their place in nature. Those that do, have a better chance of survival. • Survival of the fittest • “Fittest” describes ability to survive and was the result of successful adaptations over time. • Organisms whose “adaptations” enabled “fitness” survive and reproduce more successfully. • Cheetahs are fast because their food is fast • http://www.youtube.com/watch?v=qjivY318Aww • http://www.youtube.com/watch?v=BI8REBtjqQw&feature=related • This is called Natural Selection

16. Descent with modifications • Darwin didn’t know it, but these “naturally selected” adaptations were mutations. • The traits (adaptations) that survive are passed down to the next generation to common ancestors. • This implies “relatedness” of organisms. • You could argue that lions, tigers, panthers, and house cats are related because of their common traits.

17. If you could argue that lions, tigers, panthers, and house cats are related because of their common traits, then you could argue that gorillas, orangutans, chimpanzees, and humans are related.

19. Evidence of Evolution • Geographic Distribution Of Living Species • Similar, but different species were being discovered in different places. How did they become different, yet still similar? • Darwin concluded that the organisms descended from a common ancestor. • Darwin also noted that similar environments around the world had organisms with anatomical and physical similarities living there. Why would that happen? • Darwin concluded that similar environmental pressure caused natural selection.

20. Evidence of Evolution • The Fossil Record • Fossilized organisms in older rocks are different from those found in newer rocks. • Use them to get an approximate date of when the organism existed. • Can compare fossils to organisms alive today.

21. Evidence of Evolution • Homologous Structures and Vestigial Organs • Different species have the similar structures used for similar functions. • Evidence that these species evolved from a common ancestor.

22. Evidence of Evolution • Biochemical Homologies: Organisms that share a common ancestor have similar DNA segments amino acids, and proteins. Ex: All organisms that use oxygen have the enzyme cytochrome c.

23. Evidence of Evolution • Vestigial Structures • Structures or organs that we have but no longer use • Evidence that species share a common ancestor who once used these structures/organs Ex: Appendix, wisdom teeth, tail bone

24. Evidence of Evolution • Similarities in Embryology • Early stages of development are very similar in many different organisms

25. Summary of Darwin’s Theory • Individual organisms differ and some of this variation is inherited • Organisms produce more offspring than can survive or reproduce • Organisms compete for limited resources • Each organism has unique advantages that enable it to survive (fittest) • Species today are descended with modifications (tree of life)

26. Misconceptions http://evolution.berkeley.edu/evosite/misconceps/images/misconceptions_beavers.gif

27. Evolution by Natural Selectionchp 16 • Requires 3 conditions: • Genetic Variability: • DNA mutations create new alleles, • sexual reproduction • New alleles are heritable (gametes) • New alleles (traits) lead to differential reproductive success

28. Genetic Variation, Natural Selection, and Evolution • Remember Mendel? What do changes in genes have to with evolution? • Mendel did his work after Darwin published “On The Origin of Species,” but we now can use his work to support Darwin’s theory • Many genes need at least two ______. • These are the genetic variations of evolution. • All of the variations of a population make up the gene pool. • How many times that variation occurs is called its relative frequency.

29. Relative Frequency • The number of times that an allele occurs in a population (gene pool).

30. Sources of Genetic Variation • Main Sources of Genetic Variation • Mutations • If a mutation changes the organisms “fitness” it will effect its ability to survive and reproduce. • Gene Shuffling • The variations of the available genes that are inherited during meiosis and reproduction. • The alleles that are available in the gene pool are varied during meiosis.

31. Single Gene vs Polygenetic Traits • Single gene traits have only two alleles and therefore little variation (only two) • Rolling your tongue is controlled by a single gene: You can either roll your tongue or you cannot. • Polygenic Traits have multiple alleles and therefore lead to more variation in the trait. • Height is controlled by more than two alleles and therefore there are many different heights of people.

32. Natural Selection on Single Gene Traits • Natural selection on single gene traits canlead to changes in allele frequencies and therefore evolution! How many orange beetles and green beetles are there? Who will likely get eaten? How did the allele frequency change? What if the orange beetles were all eaten? What allele would be Expressed in greater frequency?

33. Natural Selection on Polygenic Traits • Natural selection can affect the distribution of alleles in 3 ways: • Directional Selection • Stabilizing Selection • Disruptive (Diversifying) Selection

34. Directional Selection • Individuals at one end of the curve (population) have a higher rate of fitness/survival compared to individuals in the middle or other end. • The population and its traits shift in one direction causing the population to change (adapt)

36. Natural selection Directional Natural Selection Average New average Previous average Snail coloration best adapted to conditions Number of individuals Number of individuals Average shifts Coloration of snails Coloration of snails Proportion of light-colored snails in population increases Peppered Moth Animation

37. Stabilizing Selection • Individuals in the middle of the curve (population) have a higher rate of fitness/survival compared to individuals on either end. • The population and its traits remain stable • Ie: Human babies being born: Too small premies have shorter life spans, larger babies have difficulties being born. Average is reinforced here.

39. Natural selection Stabilizing Natural Selection Dark snails eliminated Light snails eliminated Snails with extreme coloration are eliminated Number of individuals Number of individuals Coloration of snails Coloration of snails Average remains the same, but the number of individuals with intermediate coloration increases Stabilizing Animation

40. Disruptive Selection • Individuals at both ends of the curve (population) have a higher rate of fitness/survival compared to individuals in the middle. • The population and its traits essentially shift in two directions causing the population to split into two distinct groups with different phenotypes.

42. Natural selection Diversifying Natural Selection Intermediate-colored snails are selected against Snails with light and dark colors dominate Light coloration is favored Dark coloration is favored Number of individuals Number of individuals Coloration of snails Coloration of snails Number of individuals with light and dark coloration increases, and the number with intermediate coloration decreases Diversifying Animation

44. Biological Evolution • Genetic change over time (populations) • Includes Microevolution: small genetic • changes in populations (shorter time) • Macroevolution: large changes • (long time) • includes speciation • includes extinctions

45. Origins of Life: two main processes • Chemical evolution • Biological evolution

46. The Origin of the Earth • About 15 billion years ago what we know as the universe condensed into a concentrated mass and exploded (the Big Bang theory). • The explosion sent “stuff” like energy, condensed gasses, and particulate matter outward. • That stuff began to cool and come together (based on its gravity) to form stars and galaxies. • Additional stuff formed and circled those stars like our planets that circle the sun. • Earth and our galaxy formed about 4.7 billion years ago.

48. Early Earth Due to radioactive decay, uranium, thorium, and potassium keep the interior hot. Crust was volcanic spewing gasses like N2, CO2, H2 (possibly CH4 and NH3). Atmosphere was toxic, but contained the elements necessary to build biopolymers. Oxygen not present in free O2 form, yet. Sunlight and UV rays not filtered by early atmosphere. http://video.google.com/videosearch?q=early+earth&hl=en&emb=0&aq=0&oq=early+ear#

49. The Beginning of Life • Three Theories: • Life originated on another planet (doesn’t explain how it originated on this planet) • Life originated on earth, but we don’t know why (can’t test due to lack of evidence) • Life originated from nonliving sources due to random reactions over time (chemical evolution is testable)

50. 3 Basic Steps in Organic Development • Make the basic pieces (amino acids, bases, RNA) • Make more complex pieces from the basic pieces (proteins and nucleotides) • Somehow those complex pieces copy themselves (chicken or the egg?)