1. 1 Biological Evolution

2. 2 Evolutionary Bush -- thousands of earlier and later branches.

3. 3 At any given moment (e.g. the ‘present’), all we see is current diversity… all extinct forms are gone (99.9%) Time 

4. 4 Four Causes of Evolution 1.Mutation: fundamental origin of all genetic (DNA) change.

5. 5 Four Causes of Evolution 1.Mutation: fundamental origin of all genetic (DNA) change. Point mutation …some at base-pair level

6. 6 Four Causes of Evolution 1.Mutation: fundamental origin of all genetic (DNA) change. Crossing-overCrossing-over …others at grosser chromosome level

7. 7 Four Causes of Evolution 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolated populations accumulate different mutations over time. 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolated populations accumulate different mutations over time. In a continuous population, genetic novelty can spread locally.

8. 8 Four Causes of Evolution 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolated populations accumulate different mutations over time. 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolated populations accumulate different mutations over time. Local spreading of alleles

9. 9 Four Causes of Evolution 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolated populations accumulate different mutations over time. 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolated populations accumulate different mutations over time. Local spreading of alleles

10. 10 Four Causes of Evolution 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolated populations accumulate different mutations over time. 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolated populations accumulate different mutations over time. Spreading process known as ‘gene flow’.

11. 11 Four Causes of Evolution But in discontinuous populations, gene flow is blocked.

12. 12 Four Causes of Evolution Variations accumulate without inter-demic exchange

13. 13 Four Causes of Evolution Of course, this works at many loci simultaneously

14. 14 Four Causes of Evolution 1. Mutation: fundamental genetic shifts. 2. Genetic Drift: isolation  accumulate mutations 3. Founder Effect: sampling bias during immigration. When a new population is formed, its genetic composition depends largely on the gene frequencies within the group of first settlers. 1. Mutation: fundamental genetic shifts. 2. Genetic Drift: isolation  accumulate mutations 3. Founder Effect: sampling bias during immigration. When a new population is formed, its genetic composition depends largely on the gene frequencies within the group of first settlers.

15. 15 Founder Effect.-- Human example: your tribe had to live near the Bering land bridge…

16. 16 Founder Effect.-- …to invade & settle the ‘New World’!

17. 17 Audeskirk & Audeskirk, 1993 Galapagos Finches

18. 18 Four Causes of Evolution 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolation  accumulation of mutations 3.Founder Effect: immigrant sampling bias. 4.Natural Selection: differential reproduction of individuals in the same population based on genetic differences among them. 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolation  accumulation of mutations 3.Founder Effect: immigrant sampling bias. 4.Natural Selection: differential reproduction of individuals in the same population based on genetic differences among them.

19. 19 Four Causes of Evolution 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolation  accumulation of mutations 3.Founder Effect: immigrant sampling bias. 4.Natural Selection: reproductive race These 4 interact synergistically 1.Mutation: fundamental genetic shifts. 2.Genetic Drift: isolation  accumulation of mutations 3.Founder Effect: immigrant sampling bias. 4.Natural Selection: reproductive race These 4 interact synergistically

20. 20 Evidence of Evolution

21. 1.Biogeography: Geographical distribution of species

22. Evidence of Evolution 2. Fossil Record: Fossils and the order in which they appear in layers of sedimentary rock (strongest evidence)

23. 23 Fossils Oldest fossils are the approximately 3.465 billion-year-old microfossils from the Apex Chert, AustraliaOldest fossils are the approximately 3.465 billion-year-old microfossils from the Apex Chert, Australia –colonies of cyanobacteria (formerly called blue- green algae) which built real reefs built real reefs

24. 24 Fossils 1600's - Danish scientist Nicholas Steno studied the relative positions of sedimentary rocks –Layering is the most obvious feature of sedimentary rocks formed particle by particle and bed by bed, and the layers are piled one on top of the otherformed particle by particle and bed by bed, and the layers are piled one on top of the other any sequence of layered rocks, a given bed must be older than any bed on top of itany sequence of layered rocks, a given bed must be older than any bed on top of it –Law of Superposition is fundamental to the interpretation of Earth history, because at any one location it indicates the relative ages of rock layers and the fossils in them.

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26. 26 Relative and Absolute Dating Relative Dating Can determine the age of fossil with respect to another rock or fossil. You compare the depth of a fossils position, layers. Some drawbacks include limitations on accuracy. Absolute Dating Can determine the age of a fossil IN YEARS. You determine the age by finding the amount of radioactive and nonradioactive isoptope in a specimen. Some drawbacks are that it is difficult to perform in a lab.

27. 27 Types of Radioactive Isotopes Carbon 14 Use for more recent fossils (60,000 yrs old) Can be used with high accuracy Half life of 5,730 years Decays into Nitrogen Potassium 40 Used for older fossils Half life of 1.3 billion years Decays into Calcium Less common element

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29. 29 Half-life for a given radioisotope is the time for half the radioactive nuclei in any sample to undergo radioactive decay

30. 30 Half-life for a given radioisotope is the time for half the radioactive nuclei in any sample to undergo radioactive decay

31. Evidence of Evolution 3. Taxonomy: Classification of life forms.

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33. Evidence of Evolution 4. Homologous structures: structures: Structures that are similar because of common ancestry (comparative anatomy) TurtleAlligatorBirdMammals Typical primitive fish

34. Evidence of Evolution 5. Comparative Embryology: Embryology: Study of structures that appear during embryonic development

35. Evidence of Evolution 6. Molecular biology: DNA and proteins (amino acids)

36. 36 History of Theories of Evolution

37. 37 Old Theories of Evolution Jean Baptiste Lamarck (early 1800’s) proposed:Jean Baptiste Lamarck (early 1800’s) proposed: “The inheritance of acquired characteristics” He proposed that by using or not using its body parts, an individual tends to develop certain characteristics, which it passes on to its offspring. He proposed that by using or not using its body parts, an individual tends to develop certain characteristics, which it passes on to its offspring.

38. 38 “The Inheritance of Acquired Characteristics” Example:Example: A giraffe acquired its long neck because its ancestor stretched higher and higher into the trees to reach leaves, and that the animal’s increasingly lengthened neck was passed on to its offspring.

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40. 40 Charles Darwin Darwin set sail on the H.M.S. Beagle (1831-1836) to survey the south seas (mainly South America and the Galapagos Islands) to collect plants and animals.Darwin set sail on the H.M.S. Beagle (1831-1836) to survey the south seas (mainly South America and the Galapagos Islands) to collect plants and animals. On the Galapagos Islands, Darwin observed species that lived no where else in the world.On the Galapagos Islands, Darwin observed species that lived no where else in the world. These observations led Darwin to write a bookThese observations led Darwin to write a book

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42. 42 Pinta Island Intermediate shell Pinta Isabela Island Dome-shaped shell Hood Island Saddle-backed shell Hood Floreana Santa Fe Santa Cruz James Marchena Fernandina Isabela Tower Giant Tortoises of the Galápagos Islands

43. 43 http://www.galapagosislands.com

44. 44 Charles Darwin Wrote in 1859: “On the Origin of Species by Means of Natural Selection” Two main conclusions: 1.Species were not created in their present form, but evolved from ancestral species. 2.Proposed a mechanism for evolution: NATURAL SELECTION

45. 45 Darwin’s Observations 1.Most species produce more offspring than can be supported by the environment 2.Environmental resources are limited 3.Most populations are stable in size 4.Individuals vary greatly in their characteristics (phenotypes) 5.Variations that survive are inherited. (genotypes)

46. Natural Selection Individuals with favorable traits are more likely to leave more offspring better suited for their environmentIndividuals with favorable traits are more likely to leave more offspring better suited for their environment Also known as “Differential Reproduction”Also known as “Differential Reproduction”Example: English peppered moth moth (Biston betularia)Biston betularia

47. Modes of Action Natural selection has three modes of action:Natural selection has three modes of action: 1.Stabilizing selection 2.Directional selection 3.Diversifying selection Number of Individuals Size of individuals Small Large

48. 1. Stabilizing Selection Acts upon extremes and favors the intermediate.Acts upon extremes and favors the intermediate. Number of Individuals Size of individuals Small Large

49. 2.Directional Selection Favors variants of one extreme.Favors variants of one extreme. Number of Individuals Size of individuals Small Large

50. 3.Disruptive Selection Favors variants of opposite extremes.Favors variants of opposite extremes. Number of Individuals Size of individuals Small Large

51. 51 Evidence for Natural Selection

52. Artificial Selection The selective breeding of domesticated plants and animals by man.The selective breeding of domesticated plants and animals by man. Question: What’s the ancestor of the domesticated dog?Question: What’s the ancestor of the domesticated dog?

53. 53 Biodiversity

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55. 55 Biodiversity Biodiversity –increases with speciation –decreases with extinction Give-and-take between speciation and extinction  changes in biodiversity Extinction creates evolutionary opportunities for adaptive radiation of surviving species

56. Interpretations of Speciation Two theories:Two theories: 1.Gradualist Model (Neo- Darwinian): Slow changes in species overtime 2.Punctuated Equilibrium: Evolution occurs in spurts of relatively rapid change

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58. Adaptive Radiation Emergence of numerous species from a common ancestor introduced to new and diverse environments. ExampleExample: Example Hawaiian Honeycreepers

59. Convergent Evolution Species from different evolutionary branches may come to resemble one another if they live in very similar environments.Species from different evolutionary branches may come to resemble one another if they live in very similar environments. Example:Example: 1. Ostrich (Africa) and Emu (Australia). 2. Sidewinder (Mojave Desert) and Horned Viper (Middle East Desert) Horned Viper (Middle East Desert)

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61. Coevolution Evolutionary change, in which one species act as a selective force on a second species, inducing adaptations that in turn act as selective force on the first species.Evolutionary change, in which one species act as a selective force on a second species, inducing adaptations that in turn act as selective force on the first species. Example: Example: 1. Acacia ants and Acacia trees 2.Yucca Plants and Yucca moths 3.Lichen

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63. 63 Extinction Extinction of a species occurs when it ceases to exist; may follow environmental change - if the species does not evolve Evolution and extinction are affected by: –large scale movements of continents –gradual climate changes due to continental drift or orbit changes –rapid climate changes due to catastrophic events

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65. 65 Extinction Background extinction - species disappear at a low rate as local conditions changeBackground extinction - species disappear at a low rate as local conditions change Mass extinction - catastrophic, wide- spread events --> abrupt increase in extinction rateMass extinction - catastrophic, wide- spread events --> abrupt increase in extinction rate Five mass extinctions in past 500 million yearsFive mass extinctions in past 500 million years Adaptive radiation - new species evolve during recovery period following mass extinctionAdaptive radiation - new species evolve during recovery period following mass extinction

66. 66 Mass Extinctions Date of the Extinction Event Percent Species Lost Species Affected 65 mya (million years ago) 85Dinosaurs, plants (except ferns and seed bearing plants), marine vertebrates and invertebrates. Most mammals, birds, turtles, crocodiles, lizards, snakes, and amphibians were unaffected. 213 mya44Marine vertebrates and invertebrates 248 mya75-95Marine vertebrates and invertebrates 380 mya70Marine invertebrates 450 mya50Marine invertebrates http://www.geog.ouc.bc.ca/physgeog/contents/9h.html

67. 67 Community Relationships

68. 68Niche a species’ functional role in its ecosystem; includes anything affecting species survival and reproduction 1.Range of tolerance for various physical and chemical conditions 2.Types of resources used 3.Interactions with living and nonliving components of ecosystems 4.Role played in flow of energy and matter cycling

69. 69 Niche is the species’ occupation and its Habitat location of species (its address)

70. 70Niche Fundamental niche: set of conditions under which a species might exist in the absence of interactions with other species Realized niche: more restricted set of conditions under which the species actually exists due to interactions with other species

71. 71 Species Interaction

72. 72Competition any interaction between two or more species for a resource that causes a decrease in the population growth or distribution of one of the species 1.Resource competition 2.Preemptive competition 3.Exploitation competition 4.Interference competition

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74. 74Competition

75. 75Competition

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88. 88 Predation: prey adaptations Avoid detection –camouflage, mimics, –diurnal/nocturnal Avoid capture –flee –resist –escape Disrupt handling (prevent being eaten) –struggle? –protection, toxins

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100. 100 Rewards of Mutualism Food: energy and nutrients Protection: –from other species (competition, predation) –from the physical environment (shelter) Gamete or zygote dispersal (the most common of all) Pollination and fruit dispersal (between plants and animals).

101. 101 Pollination (hummingbird/bee and flowering plants) animals visit flowers to collect nectar and incidentally carry pollen from one flower to another animals get food and the plant get a pollination service

102. 102 Yucca’s only pollinator is the yucca moth. Hence entirely dependent on it for dispersal. Yucca moth caterpillar’s only food is yucca seeds. Yucca moth lives in yucca and receives shelter from plant. Yucca moth and yucca

103. 103 Lichen (Fungi-algae) Symbiotic relationship of algae and fungae…results in very different growth formas with and without symbiont. What are the benefits to the fungus?

104. 104 Seed Disperser Many birds and mammals consume fruits and incidentally disperse the seeds contained in those fruits –Animals get food and the plant gets seed dispersal (often with fertilizer)

105. 105 Ant-tended plants Ants live inside swollen Acacia thorns or hollow stems, e.g. Cecropia trees. Patrol for caterpillars or leaf predators and storm out to repel intruders…including you!

106. 106 Commensalists Benefit from the host at almost no cost to the host Eyelash mite and humans Us and starlings or house sparrows Sharks and remora

107. 107 Parasites Parasites: draw resources from host without killing the host (at least in the short term).

108. 108 Bibliography 1.Miller 11 th Edition 2.http://abandoncorporel.ca/medias/evolution.jpghttp://abandoncorporel.ca/medias/evolution.jpg 3.http://www.ne.jp/asahi/clinic/yfc/fetus.htmlhttp://www.ne.jp/asahi/clinic/yfc/fetus.html 4.rob.ossifrage.net/images/rob.ossifrage.net/images/ 5.http://www.mun.ca/biology/scarr/Five_Kingdoms_Three_Domains.htmhttp://www.mun.ca/biology/scarr/Five_Kingdoms_Three_Domains.htm 6.http://www.gpc.peachnet.edu/~ccarter/Millerlec5/Millerlec5.PPThttp://www.gpc.peachnet.edu/~ccarter/Millerlec5/Millerlec5.PPT 7.http://www.dnr.state.md.us/education/horseshoecrab/lifecycle.htmlhttp://www.dnr.state.md.us/education/horseshoecrab/lifecycle.html 8.http://www.falcons.co.uk/mefrg/Falco/13/Species.htmhttp://www.falcons.co.uk/mefrg/Falco/13/Species.htm 9.http://www.sms.si.edu/irlspec/NamSpecies.htmhttp://www.sms.si.edu/irlspec/NamSpecies.htm 10.http://www.falcons.co.uk/mefrg/Falco/13/Species.htmhttp://www.falcons.co.uk/mefrg/Falco/13/Species.htm 11.http://www.globalchange.umich.edu/globalchange1/current/lectures/complex_life/complex_life.htmlhttp://www.globalchange.umich.edu/globalchange1/current/lectures/complex_life/complex_life.html 12.http://nsm1.nsm.iup.edu/rwinstea/oparin.shtmhttp://nsm1.nsm.iup.edu/rwinstea/oparin.shtm 13.http://www.angelfire.com/on2/daviddarling/MillerUreyexp.htmhttp://www.angelfire.com/on2/daviddarling/MillerUreyexp.htm 14.http://exobiology.nasa.gov/ssx/biomod/origin_of_life_slideshow/origin_of_life_slideshow.htmlhttp://exobiology.nasa.gov/ssx/biomod/origin_of_life_slideshow/origin_of_life_slideshow.html 15.http://www.geo.cornell.edu/geology/classes/Geo104/HistoryofEarth.htmlhttp://www.geo.cornell.edu/geology/classes/Geo104/HistoryofEarth.html 16.http://astrobiology.arc.nasa.gov/roadmap/objectives/o2_cellular_components.htmlhttp://astrobiology.arc.nasa.gov/roadmap/objectives/o2_cellular_components.html 17.http://pubs.usgs.gov/gip/fossils/http://pubs.usgs.gov/gip/fossils/ 18.http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/halfli.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/halfli.html 19.http://www.accessexcellence.org/AE/AEPC/WWC/1995/teach_rad.htmlhttp://www.accessexcellence.org/AE/AEPC/WWC/1995/teach_rad.html 20.http://biology.usgs.gov/s+t/SNT/noframe/pi179.htmhttp://biology.usgs.gov/s+t/SNT/noframe/pi179.htm 21.http://www.npca.org/magazine/2001/march_april/nonnative_species.asphttp://www.npca.org/magazine/2001/march_april/nonnative_species.asp 22.http://www.bagheera.com/inthewild/spot_spkey.htmhttp://www.bagheera.com/inthewild/spot_spkey.htm 23.Biology, 2003, Prentice Hall 24.http://www.nearctica.com/ecology/habitats/island.htmhttp://www.nearctica.com/ecology/habitats/island.htm 25.http://www.valdosta.edu/~grissino/geog4900/lect_1.htmhttp://www.valdosta.edu/~grissino/geog4900/lect_1.htm