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EVOLUTION

EVOLUTION. What is this a fossil of? How do you know?. This is Archaeopteryx. Evolution is the source of biological diversity and the one process that explains the unity of life. Unity of Pattern. 3 Forms: Structure and Function Structure of Various Organisms

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EVOLUTION

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  1. EVOLUTION

  2. What is this a fossil of? • How do you know? This is Archaeopteryx

  3. Evolution is the source of biological diversity and the one process that explains the unity of life.

  4. Unity of Pattern 3 Forms: • Structure and Function • Structure of Various Organisms • Reproductive and Developmental Processes

  5. Unity of Pattern Genetic Code: the triplet sequence of bases in DNA that specifies which amino acids are incorporated into a protein. AUA GAU CAU CCC GUU ISOLEUCINE TYROSINE HISTIDINE PROLINE PHENYLALANINE

  6. Structure of Various Organisms

  7. Reproductive and Developmental www.pbs.org/wgbh/nova/odyssey/clips/

  8. Species: organisms closely similar that they can mate and produce fertile young. First, distinctiveness of species is maintained in three basic ways: Physical Behavioral Geographical

  9. Reproductive Isolation The inability of one group to interbreed successfully with any other groups.

  10. Second, mating may result in offspring, but the off spring may not live If the eggs of a bullfrog are fertilized by a leopard frog, they develop for a short time, but soon die.

  11. Third, organisms of two species may mate and produce live offspring, but the offspring are sterile, unable to reproduce. Horse Donkey Mule

  12. VARIATIONS Differences among individuals of a species.

  13. Charles Darwin • Signed on as a naturalist with the H.M.S. Beagle • Studied history and biology of South America and various islands in the Pacific. • Explored the Galapagos Islands off the coast of Ecuador.

  14. Darwin’s Finches Which finch is the: Insect Eater? Plant and some insect? Insects and some plants?

  15. The choosing of animals for breeding by selecting those with desirable traits. Examples: Horses Dogs The process by which those characteristics that permit survival and reproduction are continued and eventually replace less desirable characteristics. Example: Peppered Moth Artificial vs. Natural Selection

  16. PEPPERED MOTHS Peppered moths rest during the day on tree trunks, where they are vulnerable to being eaten by birds. In pre-industrial England, tree trunks were gray. As illustrated here, gray moths are well camouflaged on gray tree trunks; black moths stand out.

  17. When industry developed in England, pollution from factories turned tree trunks in forests in industrial areas black. As illustrated here, on black tree trunks, black moths are well camouflaged; gray moths stand out.

  18. Adaptation The characteristics that enable some members of a species or population to survive and reproduce.

  19. Jean Baptiste Lamarck Lamarck believed that giraffes stretched their necks to reach food. Their offspring and later generations inherited the resulting long necks.

  20. Lamarck also said that body parts that are not being used, such as the human appendix and pinkies are gradually disappearing. Eventually, people will be born without these parts. Lamarck also believed that evolution happens according to a predetermined plan and that the results have already been decided.

  21. Evolution and Genetics There are at least 2 major sources of variability required for evolution: Mutations Genetic Recombinations

  22. MUTATIONS • Some believe to occur in 1 mutation per 100000 gametes per generation. • Others believe this to more like 1 mutation per 1000000 gametes per generation. • Difficult to determine because many mutations cannot be detected. • Recessive traits are hidden in heterozygous individuals. • Many mutations in INTRONS: the pieces of DNA that are not translated into proteins.

  23. GENETIC RECOMBINATIONS • Result from Meiosis and Sexual Reproduction. • Gene Pool – the sum of all the alleles of a population

  24. Frequency • In general, the frequency of alleles in a population’s gene pool remains relatively stable. • This type of population is said to be in equilibrium. • 5 Factors that can change frequency: 1) Mutation 2) Migration 3) Random Change 4) Artificial or Natural Selection 5) Nonrandom Mating of Individuals

  25. Mutations Results in the introduction of a new allele and cause an immediate, but small, shift in equilibrium. ex: Bacteria – produce large number in a short time have higher influence than those producing few organisms over a long time span. 520K time-lapse movie

  26. MIGRATION The movement of organisms into or out of the population and therefore the gene pool.

  27. RANDOM CHANGE in ALLELE FREQUENCIES Genetic Drift – a random change that occurs in small populations resulting in a population with distinct characteristics.

  28. ARTIFICIAL or NATURAL SELECTION “Survival of the Fittest”

  29. Sexual Selection The nonrandom mating of individuals within the population. Speciation- the development of new species through time.

  30. Adaptive Radiation The process of dispersal, adaptation, and subsequent speciation.

  31. Punctuated Equilibria Proposed by: Niles Eldredge and Stephen Jay Gould Periods of long stability, followed by the sudden appearance of new forms. Major genetic changes may have caused new species to evolve in relatively few steps.

  32. Evidence of Evolution

  33. Extinct One that no longer exists.

  34. Sedimentary Rock Form from layers of mud, sand, and other fine particles (sediment).

  35. Embryonic Development

  36. Vestigial Structures A part of the body that no longer has a function.

  37. 1. Human appendix useless yet in other mammals, including primates, it is necessary to aid in digestion of high cellulose diet 2. Human external ear muscles still present but useless 3. Humans have tailbones and some babies occasionally have tails 4. Human wisdom teeth vestigial compared to other primates 5. Some snakes have skeletal limbs 6. Cave dwelling crayfish have eyestalks yet no eyes 7. Sometimes vestigial organs may be adapted for new uses, e.g. penguin wings can't be used for flight yet adapted for swimming 8. Kiwi, a flightless bird, has tiny stubby and useless wings

  38. A well-developed tail is characteristic of the human embryo in the second month. Usually during the third month the tail regresses and disappears as an anatomic external feature. Occasionally the tail persists and grows with the rest of the body. Tails as long as 23 cm have been reported.

  39. Patterns of Evolution Divergence: occurs when organisms within a species become so different they can no longer interbreed. South American Rhea African Ostrich

  40. Convergence: different groups have developed the same adaptations because they live in the same type of environment.

  41. Coevolution: two unrelated groups become uniquely adapted to one another. http://www.pbs.org/wgbh/evolution/library/01/3/l_013_01.html

  42. Primate & Human Evolution Primates: “order” in which monkeys, apes, and humans are classified. Characteristics: • eyes that face forward • a well-developed cerebrum • thumbs that can be used for grasping

  43. 3 Main Groups: • New world monkeys have a tail that can grasp like a hand nostrils open upward Spider monkey Howler monkey

  44. Old World Monkeys • cannot grasp with their tails, if they have one • nostrils open downward colobus Mandrill baboon

  45. Apes

  46. 3. Humanlike • Appeared around 3,000,000 years ago • Walked upright • Much shorter than modern man • 2 groups of Homo sapiens: • Neanderthal • Modern humans

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