Chapter 14: Principles of Evolution

1. Chapter 14: Principles of Evolution

2. Biogeography • Comparative Anatomy • “homologous” structures, similar • Fossil record – similar structures, carbon dating – evolution • Theories of Evolution • Catastrophism – large environmental disaster  things change • Lamarck’s • Inheritance of acquired – characteristics (organism changed in it’s lifetime – could pass those changes to offspring)

6. Wallace – “survival of the fittest” evolution • Darwin – father of evolution 1858 • Biological diversity – gene pool – there is always diversity within a species • Fitness – traits best suited for survival • Natural selection – survival of the fittest, best traits will be passed on • Artificial selection – man selected, domestication • Adaptation – allows for survival • Structural – anatomy • Behavioral – courtship, hibernation • Physiological – how the body works

8. Evidence for evolution • Radiometric dating – carbon 14 dating, radioactive substances break down in half lives – decay • Fossils – imprints of structures within rock • Comparative morphology and embryology – development prior to birth • Homologous features – similar structures, similar embryological development, • Ex. bat and bird wings • 2. Analogous features – similar functions develop differently • Ex. bat wings and butterfly wings • 3. Vestigial structures: present, no longer needed

15. Experimental evidence – • peppered moths, 2 variations white and gray • Trees with birch (lighter bark) • And lichen – more white moths • 1860’s coal  soot killed lichen  trees darken more gray moths • 1900’s less soot  lichen back lighter bark- more white moths

16. Chapter 15: How Organisms Evolve

17. Change in frequency of alleles – how genetic information changes, which traits show up more often • Five agents in microevolution • Mutation – change in genetic code, lethal, neutral, beneficial • Gene flow – beneficial traits will be passed from generation to generation – one population to another • Genetic drift – chance alteration of genes • Founder effect – species in new environment will favor certain genes • Bottleneck – cheetah – severe reduction in population small population limited gene pool, greater chance for genetic disorders • Inbreeding – homozygous limited gene pool, greater chance for genetic disorders

19. Nonrandom mating(sexual selection) – given member of a population is not equally likely to mate with any other given member “fittest” • Natural selection • Adaptations – traits best suited for survival are passed on • Fitness – best adaptive traits • Galapagos finches – Darwin – 13 finches – common ancestor, beak size and shape – and Grant’s study – evolution can quickly occur

21. Three modes • Stabilizing selection – “average” most common • Directional selection – “change in the environment” shift to one extreme or the other • Disruptive selection – splits population into 2 groups

24. Chapter 16: The Origin of Species

25. Species – interbreeding populations which produce viable offspring • II. Reproductive isolating mechanisms – keeps species separate • Prezygotic – prevents sperm from fertilizing egg • Mechanical – not physically compatible • Behavioral – “behaviors” are different, courtship song displays • 3. Temporal – breed at different times • 4. Gamete – egg and sperm cannot fuse • 5. Ecological – different habitats

31. B. Postzygotic • Hybrids – offspring may not survive or be sterile

33. III. Mechanisms of speciation • Allopatric speciation – “of other countries” • 1.species separated by geography change over time Darwin’s finches • Colonization – 1 group of finches  13 species new island, the fittest survive • Genetic divergence – over time species change due to adapting to new environment • Reproductive isolation – gene pool is separated from original gene pool – changes occur over time • Competition – fittest for environment survive to breed those characteristics to offspring • Further speciation – original species  new species

36. Sympatric speciation – absence of geologic separation, fruit flies, hawthornes, apples • ????Parapatric speciation – next to small population on the fringe of a habitat can form it’s own breeding group

38. Evolutionary change • A. Vestigial structures: present, no longer needed • Coevolution – • symbiotic relationships “mimicry” • C. Comparative biochemistry – • chemical makeup, horseshoe crab, • blood chemistry same as spiders • D. Genetics – DNA • V. Extinction: death of the last of a species • A. Habitat destruction • B. Competition

39. CHAPTER 18 SYSTEMATICS: SEEKING ORDER AMIDST DIVERSITY

40. I. Taxonomy • Linnaeus – father of taxonomy, classification system based on homologous structures • Binomial nomenclature • 2 term naming system • Genus species – identification system • Homo sapiens, Felis tigris, Felis leo

41. eastern bluebird (Sialiasialis), the western bluebird (Sialiamexicana), and the mountain bluebird (Sialiacurrucoides)—remain distinct because they do not interbreed.

42. C.Domains • 1. Archaea- ancient bacteria prokaryotes • 2. Bacteria- modern bacteria prokaryotes • 3. Eukarya- eukaryotes divided into Animal, Plant, Protist and Fungi Kingdoms • D. Kingdoms • Animal – heterotrophs, multicellular, eukaryote • Plant – autotrophs – multicellular, eukaryote • Protist – heterotrophs & autotrophs, unicellular, eukaryote • Fungi – heterotrophs, plant like, multi cellular, eukaryote • Monera – bacteria and viruses, prokaryotes

45. Taxonomic system Humans • 1. Kingdom Animalia • 2. Phylum Chordata “notochord” • 3. Class Mammalia “hair, mammary glands, • give birth to live young • 4. Order Primate “binocular vision, opposable thumb” • 5. Family Hominidae “walk upright” • 6. Genus Homo “man-like” • 7. Species sapien modern day • E. Taxonomic Key – systematic way to identify organisms using structures

46. How Many Species Exist? • Biodiversity is the total number of species in an ecosystem Between 7,000 and 10,000 new species are identified annually, mostly in the tropics Tropical rain forests are believed to be home to two-thirds of the world’s existing species, most of which have yet to be named Because tropical rain forests are being destroyed so rapidly, species may become extinct before we ever knew they existed

47. The black-faced lion tamarin Researchers estimate that no more than 260 individuals remain in the wild; captive breeding may be the black-faced lion tamarin's only hope for survival

48. The (a) tarsier, (b) lemur, and (c) liontail macaque monkey all have relatively flat faces, with forward-looking eyes providing binocular vision. All also have color vision and grasping hands. These features, retained from the earliest primates, are shared by humans

49. Primates • Some of these adaptations were inherited by humans • Large, forward-facing eyes with overlapping fields of view (allowed accurate depth perception) • Color vision • Grasping hands • Enlarged brain (facilitated hand-eye coordination and complex social interactions)

50. Oldest Hominid Fossils • Hominids include humans and extinct humanlike primates • The oldest known hominid fossils are between 6 and 7 million years old • Sahelanthropustchadensis lived more than 6 million years ago • Exhibits human-like and ape-like characteristics