1. The Evolution of Populations and the Origin of Species Chapters 23-24

2. Evolution happens to populations/ species over time. Lamarckian evolution - evolution result of change in individual in response to environment (i.e. giraffe stretching its neck to eat) - incorrect hypothesis.

3. http://necsi.org/projects/evolution/lamarck/lamarck/giraffes.jpg

4. Population composed of many different genotypes, phenotypes because of alleles carried in population. Sum total of all alleles in population - gene pool; variation in gene pool - variations in individual phenotypes.

5. http://www.brooklyn.cuny.edu/bc/ahp/LAD/C21/graphics/C21_GenePool_2.GIF

6. Measure of genetic variation in population - allele frequency of gene. # of copies of allele divided by total # of copies of gene in population.

7. http://anthro.palomar.edu/vary/images/map_of_A_blood_allele.gif

8. http://www.uni-kiel.de/medinfo/mitarbeiter/krawczak/folien/vorlesung2/img002.jpg

9. If population does not change - Hardy-Weinberg equilibrium – no evolution. Frequencies change - evolution occurring.

10. http://www.southtexascollege.edu/crj/human%20evolution.jpg

11. Conditions for population to stay at Hardy-Weinberg equilibrium: 1 Random mating occurs. 2 Population large enough to avoid random statistical fluctuations in frequencies. 3 No mutation.

12. http://w3.dwm.ks.edu.tw/bio/activelearner/18/images/ch18c2.jpg

13. 4 No migration into/out of population. 5 No natural selection. Under conditions - free flow of genes between members of same species. Alleles shuffled up from 1 generation to next.

14. http://www.artgame.com/images3/migration.jpg

15. In wildflower population of 500, 80% (0.8) of flower color alleles are R and 20% (0.2) are r. Each gamete - 1 allele for flower color; gamete drawn from gene pool at random has 0.8 chance of bearing R allele, 0.2 chance of bearing r allele.

16. http://k43.pbase.com/u29/gaocus/upload/17965482.wildflower.jpg

17. Rule of multiplication - frequencies of 3 possible genotypes in next generation. RR genotype - probability of picking 2 R alleles is 0.64 (0.8 x 0.8 = 0.64 or 64%). rr genotype - probability of picking 2 r alleles is 0.04 (0.2 x 0.2 = 0.04 or 4%).

18. Heterozygous individuals - either Rr or rR - R allele from sperm or egg. Probability of ending up with both alleles is 0.32 (0.8 x 0.2 = 0.16 for Rr, 0.2 x 0.8 = 0.16 for rR, and 0.16 + 0.16 = 0.32 or 32% for Rr + rR).

20. p = gene frequency of dominant allele, q = frequency of recessive allele; p + q = 1. Equation for Hardy-Weinberg principle is: p 2 + 2pq + q 2 = 1 2pq - # heterozygotes in population.

21. http://bill.srnr.arizona.edu/classes/182/GeneFreqs/HardyWeinberg-lg.jpeg

22. Hardy-Weinberg equilibrium, frequency of dominant homozygous curly hair (CC) is 64%. Percentage with curly hair? p = frequency dominant allele (C) q frequency recessive allele (c).

23. CC frequency 64% so p 2 =.64; p =.8. (p + q = 1) q = 1 -.8 = 2. Individual with curly hair - either CC or Cc. Percentage of population with curly hair is p 2 + 2pq =.64 + 2(.8*.2) =.96 or 96% of population.

24. Instabilities in populations Conditions can change Hardy- Weinberg equilibrium. Mutations cannot happen in equilibrium; occurs in real world. Errors in DNA replication accumulate over time as well as mutagenic factors in environment. Mutations can lead to new alleles not previously in gene pool.

25. http://www.sciencemuseum.org.uk/exhibitions/genes/images/1-3-5-1-2-2-2-2-2-0-0.jpg

26. Mutations either neutral or harmful on survival of individual. New phenotypes in population raw material that natural selection acts on to drive evolution; mutations only source of new alleles. Migration affects equilibrium. Different populations have different allelic frequencies in gene pools.

27. http://www.geo.arizona.edu/Antevs/nats104/00lect26humigrout.jpg

28. 1 population breeds with another population, frequencies of alleles change (gene flow). Small population more likely to have random event than large population.

29. http://web.pdx.edu/~mfish/image019.jpg

30. Genetic drift - changes in allele frequencies in small population caused by random events. Even in large population if small # of individuals pass on traits can decrease diversity. Individuals that do not pass traits on may have harmful alleles - alters gene pool of next generation (2 ways)

32. 1 Bottleneck - large population reduced to small # by disease, natural disaster, over- hunting/fishing. Individuals left eventually reproduce, generations not representative of original gene pool.

34. Inbreeding usually follows bottleneck; individuals with same recessive genes have more chance of passing harmful gene on. Population more susceptible to disease/infections that may not have occurred with more diversity in population.

35. http://www.brooklyn.cuny.edu/bc/ahp/LAD/C21/graphics/C21_Bottleneck_2.GIF

36. 2 Founder effect - small # of individuals of species migrate into new habitat. If only a few individuals colonize new area, new population reflect only their gene pool not larger gene pool where they came from.

37. http://www.answersingenesis.org/creation/images/v18/i3/p13_step3.JPG

38. Nonrandom mating - equilibrium cannot occur. Individuals must choose mate randomly without respect to phenotype. If phenotype influences selection, genotypes and phenotypes of population will be changed.

39. http://bioweb.wku.edu/courses/Biol430/wsquirrelHR.jpg

40. Self-fertilization in plants has this effect. Reduces # of heterozygotes in population; increases # of homozygotes. Many species exhibit sexual selection (form of nonrandom mating)

41. http://www015.upp.so-net.ne.jp/shuri/shuri_study/what_is_si.GIF

42. Natural selection - differential production of offspring based on inherited traits. Individuals with more favorable phenotypes may survive, reproduce; alters population frequencies. Fitness - key description of natural selection.

43. http://www.telomere.org/images/Sloth.jpg

44. Fitness - organism’s ability to contribute alleles, traits to future generations. Factors involved - ability to survive to reproductive age, mate and produce offspring, raise offspring to maturity. Other factors - ability to escape predation, gather food, attract mates, or care provided to offspring.

45. http://www.agpix.com/catalog/AGPix_CoTo11/large/AGPix_CoTo11_0092_Lg.jpg

46. Individual with long life but few offspring - poor fitness if other individuals have more offspring. Animals that take care of offspring - greater fitness than those that do not. Balanced by having more offspring that receive little care/fewer offspring that receive more care.

47. http://www.facstaff.bucknell.edu/ddearbor/BFAL_feeds.jpg

48. Three types of selective pressures that affect natural selection over time. Any given population, trait distribution bell-shaped.

49. http://www.csulb.edu/~kmacd/346NotesI_files/normalCurve.gif

50. 1 Stabilizing selection - not change average, tends to sharpen curve. Newborns can have problems if too large or too small at birth – stabilizing selection pushed average to 8 pounds; perfect size for newborn infant.

51. http://img.sparknotes.com/figures/A/a3aa6bb95c7d70781cc0089d17f9160f/stable.gif

52. 2 Disruptive selection - either side of bell curve favored - leads to 2 different peaks in distribution of population.

54. 3 Directional selection - change in average for trait in population occurs. Giraffes live in area where vegetation high up - favor those with longer necks - drives evolution of longer necks.

56. Kin selection - individuals with many of same alleles live with other members with same alleles. Lions live with many female relatives, help raise young, even if it is not his. Increases fitness of mother, even if it doesn’t increase fitness of male.

57. http://www.anth.ucsb.edu/faculty/gurven/images/orangatan.jpg

58. Species - group of organisms able to interbreed productively with rest of group, not with other organisms. Reproductive isolation – 2 populations of birds live in different areas never mix - not necessarily separate species.

59. http://www.lakelandwildlife.co.uk/images/species2.jpg

60. If they breed and produce fertile offspring when placed together - same species. Separation of species can promote evolution into 2 separate species - no gene flow possible between 2 species. Result of separation of gene pools over period of time.

62. Cladogenesis - formation of 2 species from 1 ancestor species. Occurs when populations occupy same area or when separated geographically from each other. 1 Allopatric speciation - populations separated by geographic barrier followed by reproductive isolation.

63. http://taxonomy.zoology.gla.ac.uk/~rdmp1c/teaching/L1/Evolution/l6/grandcanyon.gif

64. Evolution of many diversely adapted species from common ancestor - adaptive radiation.

67. 2 Sympatric speciation - speciation by populations that occupy same region. New species arise within range of parent populations. Can occur through sudden dramatic genetic change - result of polyploidy of genome.

69. Can occur within species if individual spontaneously (through mistake in meiosis) produces offspring with 2X normal chromosomal number. Also result when cross between 2 related species produces hybrid with chromosomal average of both parents.

70. http://en.wikipedia.org/wiki/Hybrid_animals A sheep goat

71. Tetraploid cannot produce fertile offspring if it mates with diploid, could fertilize itself through self- pollination if plant. Polyploidy more common in plants - has selective advantage over diploid parents.

73. Mechanisms of reproductive isolation that cause speciation divided into 2 groups. 1 Prezygotic barriers prevent 2 species from mating. Occurs several ways.

74. http://www.sci.uidaho.edu/bionet/biol115/t9_species/images/L9_Mating-Barriers.jpg

75. A Habitat isolation: species separated because of where they live. B Behavioral isolation: species have different mating habits - never interact. C Temporal isolation: breed at different times of the year. D Mechanical isolation: not anatomically correct for each other.

77. 2 Postzygotic barriers do not prevent mating - prevent formation of fertile offspring. Examples of this - reduced hybrid viability (hybrid aborts spontaneously), reduced hybrid fertility (hybrids infertile), hybrid breakdown (1 st generation hybrids viable and fertile, next generation feeble or sterile).

78. http://www.kyhorsepark.com/imh/bw/images/dmconf.jpg

79. Rate of speciation and relationship between speciation and evolution still controversy. Punctuated equilibrium - evolution occurs rapidly in association with speciation in small isolated populations followed by long periods where species changes little.