Welcome Introduce Zoology Syllabus Lecture Evolution, and Zoology Theory of Evolution by Natural Selection Origin of S

1. Welcome • Introduce Zoology • Syllabus • Lecture • Evolution, and Zoology • Theory of Evolution by Natural Selection • Origin of Species • Properties of Life Origins of Life • Prokaryotic and Eukaryotic • Levels of organization • Cell division and inheritance

2. Biology is the study of Life • Single cell to multicellular organisms

3. Cell is the basic unit of life • Unique plant cell and animal cell

4. Zoology- zoon, animal + logos, to study • is the study of Animals • Is one of the broadest fields in all of science • Variety of animals • Complexity of and the processes

5. Specializations in Zoology • Anatomy • Ecology • Genetics • Parasitology • Physiology • Entomology- • Ichthyology-

6. Ichthyologist- work to understand structure, function, ecology and evolution of fishes Studies have uncovered an amazing diversity of fishes Cichlid (‘sick-lid’)- freshwater perch-like fishes • 1000 species in Africa • 300 in South America • 3 in India • 1 in North America

7. Members of this group • Variety of color patterns • Habitats • Body forms • Feeding habits

8. Eretmodus Nip algae with chisel-like teeth

9. Tanganicodus Insect pickers

10. Perissodus Scale eaters

11. Brood their young • Dogtooth cichlid

12. The Fontosa Body form

13. An Evolutionary Perspective • Share a common evolutionary past and evolutionary forces that influence their history • Resulted in 4 to 100 million species of animals • Understand evolutionary process to understand • What it is • How it originated

14. Lamarck’s Theory of Evolution Figure 22.4 • Lamarck hypothesized that species evolve • Through use and disuse and the inheritance of acquired traits • But the mechanisms he proposed are unsupported by evidence

15. Fossils, Cuvier, and Catastrophism Figure 22.3 • The study of fossils • Helped to lay the groundwork for Darwin’s ideas • Fossils are remains or traces of organisms from the past • Usually found in sedimentary rock, which appears in layers or strata

16. England EUROPE NORTH AMERICA ATLANTIC OCEAN PACIFIC OCEAN Galápagos Islands HMS Beagle in port AFRICA SOUTH AMERICA Darwin in 1840, after his return AUSTRALIA Cape of Good Hope Andes Tasmania Cape Horn New Zealand Tierra del Fuego Figure 22.5 • Darwin’s interest in the geographic distribution of species • Was kindled by the Beagle’s stop at the Galápagos Islands near the equator west of South America

17. Darwin’s Focus on Adaptation • As Darwin reassessed all that he had observed during the voyage of the Beagle • He began to perceive adaptation to the environment and the origin of new species as closely related processes

18. (a) Cactus eater. The long,sharp beak of the cactusground finch (Geospizascandens) helps it tearand eat cactus flowersand pulp. (c) Seed eater. The large groundfinch (Geospiza magnirostris)has a large beak adapted forcracking seeds that fall fromplants to the ground. Figure 22.6a–c (b) Insect eater. The green warbler finch (Certhidea olivacea) uses itsnarrow, pointed beak to grasp insects. • From studies made years after Darwin’s voyage • Biologists have concluded that this is indeed what happened to the Galápagos finches

19. In 1844, Darwin wrote a long essay on the origin of species and natural selection • But he was reluctant to introduce his theory publicly, anticipating the uproar it would cause • In June 1858 Darwin received a manuscript from Alfred Russell Wallace • Who had developed a theory of natural selection similar to Darwin’s • Darwin quickly finished The Origin of Species • And published it the next year

20. Resistance to the Idea of Evolution • The Origin of Species • Shook the deepest roots of Western culture • Challenged a worldview that had been prevalent for centuries

21. Descent with Modification • The phrase descent with modification • Summarized Darwin’s perception of the unity of life • States that all organisms are related through descent from an ancestor that lived in the remote past

22. Sirenia (Manatees and relatives) Loxodonta africana (Africa) Elephas maximus (Asia) Loxodonta cyclotis (Africa) Hyracoidea (Hyraxes) Years ago Stegodon Mammut Mammuthus Deinotherium Platybelodon Millions of years ago Barytherium Moeritherium Figure 22.7 • In the Darwinian view, the history of life is like a tree • With multiple branchings from a common trunk to the tips of the youngest twigs that represent the diversity of living organisms

23. Natural Selection and Adaptation • Evolutionary biologist Ernst Mayr • Has dissected the logic of Darwin’s theory into three inferences based on five observations

24. Figure 22.8 • Observation #1: For any species, population sizes would increase exponentially • If all individuals that are born reproduced successfully

25. Observation #2: Nonetheless, populations tend to be stable in size • Except for seasonal fluctuations • Observation #3: Resources are limited • Inference #1: Production of more individuals than the environment can support • Leads to a struggle for existence among individuals of a population, with only a fraction of their offspring surviving

26. Figure 22.9 • Observation #4: Members of a population vary extensively in their characteristics • No two individuals are exactly alike

27. Observation #5: Much of this variation is heritable • Inference #2: Survival depends in part on inherited traits • Individuals whose inherited traits give them a high probability of surviving and reproducing are likely to leave more offspring than other individuals

28. Inference #3: This unequal ability of individuals to survive and reproduce • Will lead to a gradual change in a population, with favorable characteristics accumulating over generations

29. Artificial Selection Lateral buds Terminal bud Brussels sprouts Cabbage Flower cluster Leaves Cauliflower Kale Flower and stems Stem Broccoli Kohlrabi Wild mustard Figure 22.10 • In the process of artificial selection • Humans have modified other species over many generations by selecting and breeding individuals that possess desired traits

30. Summary of Natural Selection • Natural selection is differential success in reproduction • That results from the interaction between individuals that vary in heritable traits and their environment

31. (a) A flower mantidin Malaysia (b) A stick mantidin Africa Figure 22.11 • Natural selection can produce an increase over time • In the adaptation of organisms to their environment

32. If an environment changes over time • Natural selection may result in adaptation to these new conditions

33. Darwin’s theory explains a wide range of observations • Darwin’s theory of evolution • Continues to be tested by how effectively it can account for additional observations and experimental outcomes

34. Evolutionary Processes • Organic evolution- change in the genetic makeup of populations over time. • Source of animal diversity • Explains family relationships within animal groups • Charles Darwin • Published evidence of evolution 1859 • Proposed a mechanism • Understanding diversity of animal structure and function arose is one of the many challenges • i.e cichlid scale eaters of Africa

35. Animal classification and Evolutionary Relationship • Evolution not only explanation why animals appear and function as they do • It explains family relationships • i.e cichlid species • Groups share more of their DNA • Thus resemble each other • Genetic studies suggest • Oldest African cichlid found in Lakes Tanganyika and Kivu • These fish invades rivers, lakes Malawi, Victoria and others • Most rapid known origin of species of any animal groups

36. Figure 1.3

37. Figure 22.1 • The Origin of Species • Focused biologists’ attention on the great diversity of organisms

38. Darwin made two major points in his book • He presented evidence that the many species of organisms presently inhabiting the Earth are descendants of ancestral species • He proposed a mechanism for the evolutionary process, natural selection

39. The Darwinian revolution challenged traditional views of a young Earth inhabited by unchanging species • In order to understand why Darwin’s ideas were revolutionary • We need to examine his views in the context of other Western ideas about Earth and its life

40. Linnaeus (classification) Hutton (gradual geologic change) Lamarck (species can change) Malthus (population limits) Cuvier (fossils, extinction) Lyell (modern geology) Darwin (evolution, nutural selection) Mendel (inheritance) Wallace (evolution, natural selection) American Revolution French Revolution U.S. Civil War 1800 1850 1900 1750 1795 Hutton proposes his theory of gradualism. 1798 Malthus publishes “Essay on the Principle of Population.” 1809 Lamarck publishes his theory of evolution. Lyell publishes Principles of Geology. 1830 Darwin travels around the world on HMS Beagle. 1831–1836 1837 Darwin begins his notebooks on the origin of species. 1844 Darwin writes his essay on the origin of species. 1858 Wallace sends his theory to Darwin. TheOrigin of Species is published. 1859 1865 Mendel publishes inheritance papers. Figure 22.2 • The historical context of Darwin’s life and ideas

41. Homology, Biogeography, and the Fossil Record • Evolutionary theory • Provides a cohesive explanation for many kinds of observations

42. Homology • Homology • Is similarity resulting from common ancestry

43. Anatomical Homologies Human Cat Bat Whale Figure 22.14 • Homologous structures between organisms • Are anatomical resemblances that represent variations on a structural theme that was present in a common ancestor

44. Pharyngeal pouches Post-anal tail Chick embryo Human embryo Figure 22.15 • Comparative embryology • Reveals additional anatomical homologies not visible in adult organisms

45. Vestigial organs • Are some of the most intriguing homologous structures • Are remnants of structures that served important functions in the organism’s ancestors

46. Molecular Homologies • Biologists also observe homologies among organisms at the molecular level • Such as genes that are shared among organisms inherited from a common ancestor

47. Homologies and the Tree of Life • The Darwinian concept of an evolutionary tree of life • Can explain the homologies that researchers have observed

48. Percent of Amino Acids That Are Identical to the Amino Acids in a Human Hemoglobin Polypeptide Species 100% Human Rhesus monkey 95% Mouse 87% Chicken 69% Frog 54% 14% Figure 22.16 Lamprey • Anatomical resemblances among species • Are generally reflected in their molecules, their genes, and their gene products

49. Biogeography • Darwin’s observations of the geographic distribution of species, biogeography • Formed an important part of his theory of evolution

50. NORTH AMERICA Sugar glider AUSTRALIA Flying squirrel Figure 22.17 • Some similar mammals that have adapted to similar environments • Have evolved independently from different ancestors