1. Evidence for Evolution Was Darwin Wrong? Thursday, May 1 st

3. EVOLUTION It does not mean random It does not mean to improve It does not mean morphing during a lifetime It does not mean abiogenesis It means CHANGE OVER TIME

4. What is “fitness”? What does it mean to be “fit”? –To be able to survive AND reproduce

6. The table below gives descriptions of four female mice that live in a beach area which has mostly tan sand with scattered plants. According to the definition given for fitness, which mouse would biologists consider the fittest? Explain why this mouse would be the fittest... Fur colorBlackTanTan and Black Cream Age at death 2 months8 months4 months2 months # pups produced by each female 01130 Running speed 8 m/min6 m/min7 m/min5 m/min

7. What is “fitness”? What does it mean to be “fit”? –To be able to survive AND reproduce offspring that can THEN reproduce *

8. Below are descriptions of 4 male lions. According to our newest definition of fitness, which lion would biologists consider the “fittest”? NameGeorgeBrianSpotBob Age at death 13 yrs16 yrs12 yrs10 yrs # of cubs fathered 192520 # of cubs surviving to adulthood 1514 19 Size10 ft8.5 ft9 ft

9. Natural Selection vs Evolution Evolution = The change in the inherited characteristics of biological populations over successive generations Natural selection = It is a key MECHANISM of evolution is the only known cause of adaptation, but not the only known cause of evolution *

10. Who was Charles Darwin? English naturalist Evolution resulted from natural selection –The struggle for existence is SIMILAR to artificial selection and selective breeding Dog breeds Beef cattle *

11. HMS The Beagle

12. The 4 Components of NS 1. Variation = exists among individuals in a population of species 2. Inheritance = Some traits are consistently passed on from parent to offspring. 3. Population growth = Most populations have more offspring each year than local resources can support leading to a struggle for resources. 4. Survival of the Fittest = Individuals with advantageous variations will be more likely to survive and reproduce *

13. Who was Charles Darwin? Process of natural selection: –Populations of organisms can evolve if individuals having certain heritable traits leave more offspring than others Variations = adaptations: –Inherited characteristics that enhance organisms’ survival and/or reproduction November 24, 1859 *

14. Who was Charles Darwin? Cladistics –Hierarchical classification of species based on evolutionary ancestry –Cladograms = Evolutionary “Tree of Life” –Makes no distinction between extinct and non-extinct species Appropriate to include extinct species in the group of organisms being analyzed *

16. Cat, lion, seal & human

18. Who influenced Darwin? Carolus Linnaeus (1750’s) –Taxonomy (scientific groupings/names) –Used latin as the universal language Ex: Canis lupis – wolf Ex: Homo sapien - human Jean-Bapiste Lamarck (1800) –Organisms change through use and disuse –Inheritance of acquired characteristics –Environments are what cause organisms to change

21. Who influenced Darwin? James Hutton (1785) –Gradualism (rock formations - SLOW) –Earth was transformed by imperceptibly slow changes So natural selection/evolution could be really slow too Charles Lyell (1830’s) –Principal of Uniformitarianism –Geological forces at work in the present day = same as those that operated in the past –The past can be found in the present

22. What is the Evidence for Evolution? Paleontology –Investigates extinct life-forms as revealed in the fossil record We call this FOSSIL EVIDENCE Classifying ancient organisms is difficult –Many do not “fit” well into the modern form of taxonomy (Classification)

23. What is the Evidence for Evolution? DNA is made of 4 nucleotides Adenine, thymine, cystosine and guanine –Everything living is made of the same material, it’s just rearranged differently We call this MOLECULAR EVIDENCE

24. What is the Evidence for Evolution? You can trace similarities as far back as the beginning –All fungi, plant and animal cells have nuclei –All living organisms have RNA and DNA

25. What is the Evidence for Evolution? Biogeography –The study of the geographical distribution of living creatures Which species inhabit which parts of the planet and why? –Closely related species tend to be found: On the same continent (similar species of zebra) Or within the same group of oceanic islands (diff. finches on the Galapagos Islands)

26. What is the Evidence for Evolution? Isolation + Time + Adaptations to local environmental conditions = new species

27. What is Comparative Anatomy?  The science of anatomical shape and design An organism’s body structure –Called its “basic plan” We call this ANATOMICAL EVIDENCE Can you guess what is similar between all of the organisms on the next slide?

28. What is Comparative Anatomy? All of these organisms have an INTERNAL skeleton

29. What is Comparative Anatomy? Homologous structures –Similar structures that related species have inherited from a common ancestor –Ex: Paired bones of the lower leg (tibia and fibula) can be traced back to the 1 st “bird”, Archaeopteryx

31. What is Comparative Anatomy? Analogous vs Homologous Wings –Maple seed –Albatross –Analogous Both allow the organism to travel on the wind –Both did not develop from the same structure

32. What is Comparative Anatomy? Vestigial structures –Structures that have lost most of their original function in a species through evolution –Appear to serve no useful function Examples: –Snakes: tiny pelvic bones & limb bones –Flightless beetles: have wings sealed that never open

33. What is Comparative Anatomy? Vestigial organs are often exactly the same as organs that are useful in other species –Our tailbone is homologous to the functional tail of other primates –Organisms having vestigial structures probably share a common ancestry with organisms that have use for the organ.

34. What is Comparative Anatomy?

35. Embryology –Examines the revealing stages of development that embryos pass through before birth or hatching –Many organisms look extremely similar when developing in the womb

36. What is Comparative Anatomy? Embryonic structures can be adapted to different ultimate uses, for example, pharyngeal arches ("gill slits") –fish gill cartilage, the reptilian jaw, and the mammalian middle ear Developmental ancestry: structures arise from the same tissue in embryonal development

37. What are the different types of evolution? Divergent –Adaptive radiation 2 or more related species become more and more dissimilar Adapting to different environments –Kit fox  plains & deserts (sandy colored fur & large ears) –Red fox  mixed farmlands & forests (red fur)

38. What are the different types of evolution? Convergent –Unrelated species become more and more similar in appearance –Adapting to the same kind of environment –Creates analogous structures Example – wings of –Pteranodon –Bats –Birds

39. What are the different types of evolution? Co-evolution  the evolution of 2 species totally dependent on each other –An explosion of insect diversity seemed to correlate with the abundance of flowering plants. Angiosperms (flowering plants) depend on pollinating insects in order to survive and the insects depend on flowers for food.

40. What are the different types of evolution? Gradualism –Change is SLOW, CONSTANT & CONSISTENT –Selection & variation occur more gradually –Over a short period of time, it’s hard to notice –Very gradually, over a long period of time, the population changes

42. What are the different types of evolution? Punctuated equilibrium –CHANGE COMES IN SPURTS –Predicts that a lot of evolutionary change takes place in short periods of time –Speciation is likely to occur at the edge of a population Where a small group can become separated geographically from the main body population

46. So what is evolution anyway? It’s not necessarily a DECISION – the organisms that are best at surviving will produce babies (offspring) The organisms that cannot survive… well, they can’t really have offspring if they’re dead, right? We call that NATURAL SELECTION or Survival of the Fittest –Only the fit survive and reproduce – mutations that affect an organism prior to reproduction tend to get “eliminated”

49. Evidence for Evolution THE TOP EIGHT 8. Wings on flightless birds –Ostriches –Emus –Kiwi 7. Hind leg bones in whales –Baleen and humpback whales

50. Evidence for Evolution 6. Erector pili and body hair –When you get scared, your hair stands on end –When mammals get scared, it makes them look BIGGER 5. The human tailbone –Was once used for balance, communication (think dogs) or a prehensile limb

51. Evidence for Evolution 4. Wisdom teeth in humans –Gorillas have these teeth to help chew and grind food –We brush our teeth, so we don’t lose our teeth as often 3. Whiptail lizards –There are ALL female! –These lizards literally clone themselves

52. Evidence for Evolution 2. Male breast tissue and nipples –This tissue is not functional, although a small percentage of males have been able to lactate –ALL mammals, male and female, have mammary glands –Males can also contract breast cancer

53. Evidence for Evolution 1.The Human Appendix –In herbivores, the appendix helps by breaking down plant material for digestion –Unfortunately, this organ no longer helps us with digestion what so ever –In 2006, over 300,000 appendectomies were performed in the United State and over 400 people have died from appendicitis.