The origin of species

1. Chapter 24 The Origin of Species

6. LE 24-2 Anagenesis Cladogenesis

9. LE 24-3 Similarity between different species. Diversity within a species.

13. LE 24-4a Prezygotic barriers impede mating or hinder fertilization if mating does occur Postzygotic barriers prevent a hybrid zygote from developing into a viable, fertile adult REDUCED HYBRID VIABILITY REDUCED HYBRID FERTILITY HYBRID BREAKDOWN HABITAT ISOLATION TEMPORAL ISOLATION BEHAVIORAL ISOLATION MECHANICAL ISOLATION GAMETIC ISOLATION Reduced hybrid viability Fertilization Viable, fertile offspring Reduced hybrid fertility Hybrid breakdown Mating attempt Gametic isolation Fertilization Mechanical isolation Behavioral isolation Temporal isolation Habitat isolation Individuals of different species

23. LE 24-4aa Prezygotic barriers impede mating or hinder fertilization if mating does occur HABITAT ISOLATION TEMPORAL ISOLATION BEHAVIORAL ISOLATION MECHANICAL ISOLATION GAMETIC ISOLATION Mating attempt Gametic isolation Fertilization Mechanical isolation Behavioral isolation Temporal isolation Habitat isolation Individuals of different species

31. LE 24-4ab Postzygotic barriers prevent a hybrid zygote from developing into a viable, fertile adult REDUCED HYBRID VIABILITY REDUCED HYBRID FERTILITY HYBRID BREAKDOWN Reduced hybrid viability Fertilization Viable, fertile offspring Reduced hybrid fertility Hybrid breakdown

35. LE 24-5 Allopatric speciation Sympatric speciation

37. LE 24-6 A. harrisi A. leucurus

39. LE 24-7a Initial population of fruit flies (Drosophila pseudoobscura) Mating experiments after several generations Some flies raised on maltose medium Some flies raised on starch medium

40. LE 24-7b Female Female Starch Maltose Starch Maltose Male Same population Different populations Male 20 8 Mating frequencies in experimental group Mating frequencies in control group 18 15 15 12 Same population Different populations 9 22

43. LE 24-8 Failure of cell division in a cell of a growing diploid plant after chromosome duplication gives rise to a tetraploid branch or other tissue. Gametes produced by flowers on this tetraploid branch are diploid. Offspring with tetraploid karyo- types may be viable and fertile—a new biological species. 2 n = 6 4 n = 12 4 n 2 n

45. LE 24-9 Species B 2 n = 6 Species A 2 n = 4 Normal gamete n = 3 Normal gamete n = 3 2 n = 10 Unreduced gamete with 4 chromosomes Unreduced gamete with 7 chromosomes Hybrid with 7 chromosomes Viable fertile hybrid (allopolyploid) Meiotic error; chromosome number not reduced from 2 n to n

47. LE 24-10 Normal light Monochromatic orange light P. pundamilia P. nyererei

52. LE 24-12 KAUAI 5.1 million years OAHU 3.7 million years HAWAII 0.4 million years 1.3 million years MAUI MOLOKAI LANAI Argyroxiphium sandwicense Dubautia linearis Dubautia scabra Dubautia waialealae Dubautia laxa N

55. LE 24-13 Time Gradualism model Punctuated equilibrium model

59. LE 24-14 Complex camera-type eye Pinhole camera-type eye Eye with primitive lens Patch of pigmented cells Eyecup Pigmented cells (photoreceptors) Epithelium Nerve fibers Fluid-filled cavity Epithelium Pigmented layer (retina) Optic nerve Pigmented cells Nerve fibers Cornea Cellular fluid (lens) Optic nerve Cornea Lens Optic nerve Retina

62. LE 24-15a Differential growth rates in a human Newborn Age (years) Adult 2 5 15

64. LE 24-15b Chimpanzee fetus Chimpanzee adult Human fetus Human adult Comparison of chimpanzee and human skull growth

66. LE 24-16 Ground-dwelling salamander Tree-dwelling salamander

71. LE 24-18 Chicken leg bud Region of Hox gene expression Zebrafish fin bud

73. LE 24-19 Hypothetical vertebrate ancestor (invertebrate) with a single Hox cluster First Hox duplication Hypothetical early vertebrates (jawless) with two Hox clusters Second Hox duplication Vertebrates (with jaws) with four Hox clusters

75. LE 24-20 Pleistocene Sinohippus Recent Pliocene Anchitherium Miocene Paleotherium Oligocene Propalaeotherium Eocene Pachynolophus Hyracotherium Mesohippus Miohippus Orohippus Epihippus Key Grazers Browsers Hypohippus Parahippus Archaeohippus Merychippus Callippus Megahippus Pliohippus Nannippus Hipparion Neohipparion Hippidion and other genera Equus