1. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Unit 5 Review The Evolutionary History of Biological Diversity Not Complete!! (Nothing on plants yet)

2. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The “RNA World” and the Dawn of Natural Selection The first genetic material – Was probably RNA, not DNA

3. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings RNA molecules called ribozymes have been found to catalyze many different reactions, including – Self-splicing – Making complementary copies of short stretches of their own sequence or other short pieces of RNA Figure 26.5 Ribozyme (RNA molecule) Template Nucleotides Complementary RNA copy 3 5 5

4. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The oldest known fossils are stromatolites – Rocklike structures composed of many layers of bacteria and sediment – Which date back 3.5 billion years ago

5. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Chapter 27 Prokaryotes

6. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings A phylogeny of some major prokaryote taxa based on molecular systematics: Domain Bacteria Domain Archaea Domain Eukarya Alpha Beta Gamma Epsilon Delta Proteobacteria Chlamydias Spirochetes Cyanobacteria Gram-positive bacteria Korarchaeotes Euryarchaeotes Crenarchaeotes Nanoarchaeotes Eukaryotes Universal ancestor

7. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Archaea Archaea share certain traits with bacteria – And other traits with eukaryotes

8. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Some “Extremophile” Archaea Extreme thermophiles thrive in… – very hot environments Figure 27.1

9. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Chemical Recycling Prokaryotes play a major role – In the continual recycling of chemical elements between the living and nonliving components of the environment

10. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Symbiotic Relationships Many prokaryotes – Live with other organisms in symbiotic relationships such as mutualism and commensalism Figure 27.15 Aren’t my symbiotic bacterial headlights cool?

11. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Chapter 28 Protists

12. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Endosymbiosis in Eukaryotic Evolution Evidence supports endosymbiosis as an origin of eukaryote diversity:

13. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Traditional …… and …… alternative hypotheis:

14. Diplomonads Parabasalids Kinetoplastids Euglenids Dinoflagellates Apicomplexans Ciliates Oomycetes Diatoms Golden algae Brown algae Chlorarachniophytes Foraminiferans Radiolarians Gymnamoebas Entamoebas Plasmodial slime molds Cellular slime molds Fungi Choanoflagellates Metazoans Red algae Chlorophytes Charophyceans Plants Ancestral eukaryote Chlorophyta Plantae Rhodophyta Animalia Fungi (Opisthokonta) (Viridiplantae) Diplomonadida Parabasala Euglenozoa AlveolataStramenopila Cercozoa Radiolaria Amoebozoa Arrows indicate probable instances of endosymbiosis Note connections for fungi, plantae, & anamalia

15. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings ALMOST sexual reproduction… CONJUGATION AND REPRODUCTION 8 7 2 MICRONUCLEAR FUSION Diploid micronucleus Haploid micronucleus MEIOSIS Compatible mates Key Conjugation Reproduction Macronucleus Two cells of compatible mating strains align side by side and partially fuse. 1 Meiosis of micronuclei produces four haploid micronuclei in each cell. 2 3 Three micronuclei in each cell disintegrate. The remaining micro- nucleus in each cell divides by mitosis. The cells swap one micronucleus. 4 The cells separate. 5 Micronuclei fuse, forming a diploid micronucleus. 6 Three rounds of mitosis without cytokinesis produce eight micronuclei. 7 The original macro- nucleus disintegrates. Four micronuclei become macronuclei, while the other four remain micronuclei. 8 Two rounds of cytokinesis partition one macronucleus and one micronucleus into each of four daughter cells. 9

16. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Sexual reproduction almost certainly evolved in the protists

17. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Clade Viriplantidai Most chlorophytes have complex life cycles – sexual and asexual reproductive stages

18. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Phyla of two animal phyla, Cnidaria and Porifera, appear first. – The rest appear suddenly in the Cambrian Figure 26.17 Early Paleozoic era (Cambrian period) Millions of years ago 500 542 Late Proterozoic eon Sponges Cnidarians Echinoderms Chordates Brachiopods Annelids Molluscs Arthropods

19. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Chapter 32 An Introduction to Animal Diversity

20. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Welcome to Your Kingdom Figure 32.1 Animals (except the sponges) are… – multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers

21. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Zygote Cleavage Eight-cell stage Cleavage Blastula Cross section of blastula Blastocoel Gastrula Gastrulation Endoderm Ectoderm Blastopore Early Embryonic Development Figure 32.2 In most animals, cleavage results in the formation of a multicellular stage called a blastula. The blastula of many animals is a hollow ball of cells. 3 The endoderm of the archenteron de- velops into the tissue lining the animal’s digestive tract. 6 The blind pouch formed by gastru- lation, called the archenteron, opens to the outside via the blastopore. 5 Most animals also undergo gastrulation, a rearrangement of the embryo in which one end of the embryo folds inward, expands, and eventually fills the blastocoel, producing layers of embryonic tissues: the ectoderm (outer layer) and the endoderm (inner layer). 4 Only one cleavage stage–the eight-cell embryo–is shown here. 2 The zygote of an animal undergoes a succession of mitotic cell divisions called cleavage. 1

22. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The common ancestor of living animals – May have lived 1.2 billion–800 million years ago – May have resembled modern choanoflagellates, protists that are the closest living relatives of animals Figure 32.3 Single cell Stalk

23. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Cleavage In protostome development – Cleavage is spiral and determinate In deuterostome development – Cleavage is radial and indeterminate Figure 32.9a Protostome development (examples: molluscs, annelids, arthropods) Deuterostome development (examples: echinoderms, chordates) Eight-cell stage Spiral and determinate Radial and indeterminate (a) Cleavage. In general, protostome development begins with spiral, determinate cleavage. Deuterostome development is characterized by radial, indeterminate cleavage.

24. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Coelom Formation Archenteron Mesoderm Coelom Blastopore Mesoderm Schizocoelous: solid masses of mesoderm split and form coelom Enterocoelous: folds of archenteron form coelom Coelom Protostomes:Deuterostomes:

25. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings newer animal phylogeny based mainly on molecular data Figure 32.11 Calcarea Silicarea Ctenophora Cnidaria Echinodermata Chordata Brachiopoda Phoronida Ectoprocta Platyhelminthes Nemertea MolluscaAnnelida Rotifera Nematoda Arthropoda “Radiata” “Porifera” Deuterostomia Lophotrochozoa Ecdysozoa Bilateria Eumetazoa Metazoa Ancestral colonial flagellate

26. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Chapter 33 Invertebrates

27. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings A review of animal phylogeny Ancestral colonial choanoflagellate Eumetazoa Bilateria Deuterostomia Porifera Cnidaria Other bilaterians (including Nematoda, Arthropoda, Mollusca, and Annelida) Echinodermata Chordata Figure 33.2

28. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Phylum Porifera Sponges are suspension feeders – Capturing food particles suspended in the water that passes through their body Azure vase sponge (Callyspongia plicifera) Osculum Spicules Water flow Flagellum Collar Choanocyte Phagocytosis of food particles Amoebocyte Choanocytes. The spongocoel is lined with feeding cells called choanocytes. By beating flagella, the choanocytes create a current that draws water in through the porocytes. Spongocoel. Water passing through porocytes enters a cavity called the spongocoel. Porocytes. Water enters the epidermis through channels formed by porocytes, doughnut-shaped cells that span the body wall. Epidermis. The outer layer consists of tightly packed epidermal cells. Mesohyl. The wall of this simple sponge consists of two layers of cells separated by a gelatinous matrix, the mesohyl (“middle matter”). The movement of the choanocyte flagella also draws water through its collar of fingerlike projections. Food particles are trapped in the mucus coating the projections, engulfed by phagocytosis, and either digested or transferred to amoebocytes. Amoebocyte. Amoebocytes transport nutrients to other cells of the sponge body and also produce materials for skeletal fibers (spicules). 5 6 7 4 3 2 1 Figure 33.4

29. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Phylum Cnidaria There are two variations on this body plan – The sessile polyp and the swimming medusa Mouth/anus Tentacle Gastrovascular cavity Gastrodermis Mesoglea Epidermis Tentacle Body stalk Mouth/anus Medusa Polyp Figure 33.5

30. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Bilateral Animals The vast majority of animal species belong to the clade Bilateria – Which consists of animals with bilateral symmetry and triploblastic development

31. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

32. Phylum Platyhelminthes - Turbellaria The best-known turbellarians, commonly called planarians – Have light-sensitive eyespots and centralized nerve nets Pharynx. The mouth is at the tip of a muscular pharynx that extends from the animal’s ventral side. Digestive juices are spilled onto prey, and the pharynx sucks small pieces of food into the gastrovascular cavity, where digestion continues. Digestion is completed within the cells lining the gastro- vascular cavity, which has three branches, each with fine subbranches that pro- vide an extensive surface area. Undigested wastes are egested through the mouth. Ganglia. Located at the anterior end of the worm, near the main sources of sensory input, is a pair of ganglia, dense clusters of nerve cells. Ventral nerve cords. From the ganglia, a pair of ventral nerve cords runs the length of the body. Gastrovascular cavity Eyespots Figure 33.10

33. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings - Lophotrochozoa Clade; Pylum Mollusca Visceral mass Mantle Foot Coelom Intestine Gonads Mantle cavity Anus Gill Nerve cords Esophagus Stomach Shell Radula Mouth Nephridium. Excretory organs called nephridia remove metabolic wastes from the hemolymph. Heart. Most molluscs have an open circulatory system. The dorsally located heart pumps circulatory fluid called hemolymph through arteries into sinuses (body spaces). The organs of the mollusc are thus continually bathed in hemolymph. The long digestive tract is coiled in the visceral mass. Radula. The mouth region in many mollusc species contains a rasp-like feeding organ called a radula. This belt of backward- curved teeth slides back and forth, scraping and scooping like a backhoe. The nervous system consists of a nerve ring around the esophagus, from which nerve cords extend. Figure 33.16

34. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

37. Phylum Arthropoda: Molecular evidence now suggests – living arthropods consist of four major lineages that diverged early in the evolution of the phylum Table 33.5

38. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Scorpions have pedipalps that are pincers specialized for defense and the capture of food. The tip of the tail bears a poisonous stinger. (a) Dust mites are ubiquitous scavengers in human dwellings but are harmless except to those people who are allergic to them (colorized SEM). (b) Web-building spiders are generally most active during the daytime. (c) 50 µm Figure 33.31a–c Cheliceriforms – Phylum Arthropoda Most modern cheliceriforms are arachnids – A group that includes spiders, scorpions, ticks, and mites

39. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Insecta – Phylum Arthropoda

40. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Crustaceans – Phylum Arthropoda Planktonic crustaceans are primary consumers in many food chains – (a) copopods (among the most numerous animals) – (b) krill Planktonic crustaceans known as krill are consumed in vast quantities by whales. (b)

41. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Table 33.6

42. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Sea Stars – Phylum Echinodermata Sea stars, class Asteroidea – Have multiple arms radiating from a central disk The undersurfaces of the arms – Bear tube feet, each of which can act like a suction disk (a) A sea star (class Asteroidea) Figure 33.40a

43. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Chapter 34 Vertebrates

44. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Derived Characters of Chordates All chordates share a set of derived characters – Although some species possess some of these traits only during embryonic development Muscle segments Brain Mouth Anus Dorsal, hollow nerve cord Notochord Muscular, post-anal tail Pharyngeal slits or clefts Figure 34.3

45. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Chordates Craniates Vertebrates Gnathostomes Osteichthyans Lobe-fins Tetrapods Amniotes Milk Amniotic egg Legs Lobed fins Lungs or lung derivatives Jaws, mineralized skeleton Vertebral column Cranium Brain Notochord & more Ancestral deuterostome Echinodermata (sister group to chordates) Urochordata (tunicates) Cephalochordata (lancelets) Myxini (hagfishes) Cephalaspidomorphi (lampreys) Chondrichthyes (sharks, rays, chimaeras) Actinopterygii (ray-finned fishes) Actinistia (coelacanths) Dipnoi (lungfishes) Amphibia (frogs, salamanders) Reptilia (turtles, snakes, crocodiles, birds) Mammalia (mammals) Follow along on your own copy of this cladogram Derived Characters of Chordates

46. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Dorsal, Hollow Nerve Cord The dorsal nerve cord – Develops from a plate of ectoderm that rolls into a tube dorsal to the notochord – Develops into the central nervous system: the brain and the spinal cord Notochord Ectoderm

47. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Gene expression in lancelets nervous system development is representative of that in vertebrates. BF1 Otx Hox3 Forebrain Midbrain Hindbrain Nerve cord of lancelet embryo Brain of vertebrate embryo (shown straightened) Figure 34.6

48. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Hagfishes The least derived craniate lineage that still survives – Is class Myxini, the hagfishes Figure 34.9 Slime glands

49. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Derived Characters of Gnathostomes Gnathostomes (“jaw-mouth”) – have jaws evolved from skeletal supports of the pharyngeal slits Mouth Gill slits Cranium Skeletal rods Figure 34.13

50. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The Origin of Tetrapods In one lineage of lobe-fins – The fins became progressively more limb-like while the rest of the body retained adaptations for aquatic life Tetrapod limb skeleton Bones supporting gills Figure 34.19

51. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Amphibians The tetrapod class Amphibia – about 4,800 species – moist skin complements lungs in gas exchange

52. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Amphibian means “___ life” – A reference to the metamorphosis of an aquatic larva into a terrestrial adult Figure 34.22a–c (a) The male grasps the female, stimulating her to release eggs. The eggs are laid and fertilized in water. They have a jelly coat but lack a shell and would desiccate in air. (b) The tadpole is an aquatic herbivore with a fishlike tail and internal gills. (c) During metamorphosis, the gills and tail are resorbed, and walking legs develop.

53. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Amniote clade: – tetrapods with a terrestrially adapted egg – living members are reptiles, including birds mammals

54. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Shell Albumen Yolk (nutrients) Amniotic cavity with amniotic fluid Embryo Yolk sac. The yolk sac contains the yolk, a stockpile of nutrients. Blood vessels in the yolk sac membrane transport nutrients from the yolk into the embryo. Other nutrients are stored in the albumen (“egg white”). Allantois. The allantois is a disposal sac for certain metabolic wastes pro- duced by the embryo. The membrane of the allantois also functions with the chorion as a respiratory organ. Amnion. The amnion protects the embryo in a fluid-filled cavity that cushions against mechanical shock. Chorion. The chorion and the membrane of the allantois exchange gases between the embryo and the air. Oxygen and carbon dioxide diffuse freely across the shell. Extraembryonic membranes

55. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Early Evolution of Mammals Mammals evolved from synapsids – In the late Triassic ~200 mya Synapsids Ancestral amniote Reptiles Diapsids Archosaurs Saurischians Lepidosaurs Dinosaurs Parareptiles Turtles Crocodilians Pterosaurs Ornithischian dinosaurs Saurischian dinosaurs other than birds Birds Plesiosaurs Ichthyosaurs Tuatara Squamates Mammals

56. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Phylogenetic relationships of mammals

57. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Anthropoid fossils, about 45 million years old – Indicate that tarsiers are most closely related to anthropoids

58. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Hominoids, informally called apes – branched from old world monkeys 25-35 mya. Figure 34.40a–e (a) Gibbons, such as this Muller's gibbon, are found only in southeastern Asia. Their very long arms and fingers are adaptations for brachiation. (b) Orangutans are shy, solitary apes that live in the rain forests of Sumatra and Borneo. They spend most of their time in trees; note the foot adapted for grasping and the opposable thumb. (c) Gorillas are the largest apes: some males are almost 2 m tall and weigh about 200 kg. Found only in Africa, these herbivores usually live in groups of up to about 20 individuals. (d) Chimpanzees live in tropical Africa. They feed and sleep in trees but also spend a great deal of time on the ground. Chimpanzees are intelligent, communicative, and social. (e) Bonobos are closely related to chimpanzees but are smaller. They survive today only in the African nation of Congo.

59. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Australopiths Australopith hominids lived between 4 & 2 mya – ex: “Lucy” – Some species walked fully erect – Human-like hands and teeth – Oldest evidence of tool use—cut marks on animal bones Is 2.5 mya

60. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Early Homo The earliest fossils in our genus, Homo, – Are those of the species Homo habilis, ranging in age from about 2.4 to 1.6 mya Stone tools have been found with H. habilis – species name means “handy man”

61. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Homo ergaster – Was the first fully bipedal, large- brained hominid – Existed between 1.9 and 1.6 million years – The Turkana boy Figure 34.43

62. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Homo erectus – Originated in Africa approximately 1.8 million years ago – Was the first hominid to leave Africa

63. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Homo sapiens – Appeared in Africa at least 160,000 years ago Figure 34.44