1. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Slides prepared by Jay Withgott and Heidi Marcum PowerPoint ® Slides prepared by Jay Withgott and Heidi Marcum Ch 5 ( = Ch 3 in 4 th ed) Evolution, Biodiversity, and Population Ecology Part 1: Foundations of Environmental Science Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

2. Study Guide Natural selection How evolution influences biodiversity Reasons for species extinction Ecological organization Population characteristics Population ecology Monte Verde Cloud Forest Costa Rica (~10 o N)

3. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Striking gold in Costa Rica Golden toads were discovered in 1964, in Monteverde The mountainous cloud forest has a perfect climate for amphibians Unfortunately, they became extinct within 25 years -Due to global warming’s drying effect on the forest Golden Toads at Monte Verde

4. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Evolution: → Earth’s biodiversity (A gradual process in which something changes/develops into different form). Development of more complicated form of life from ealier, simpler form. A process in which groups of organisms (Species), change and develops over through natural (and artificial) process so that descendants differ morphologically and physiologically, producing new species (Speciation). Biological evolution : genetic change in populations of organisms across generations May be random or directed by natural selection Natural Selection: the process by which traits that enhance survival and reproduction are passed on more frequently to future generations than those that do not

5. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Evolution : → Earth’s biodiversity A gradual process in which something changes/develops into different form Biological evolution: Development of more complicated form of life from earlier & simpler form through genetic changes in populations of organisms across generations by natural or artificial selection A process in which groups of organisms (Species), change and develops through natural (& artificial) process so that descendants differ morphologically and physiologically, producing new species (Speciation). Natural Selection: the process by which traits that enhance survival and reproduction are passed on more frequently to future generations than those that do not

6. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Understanding Evolution is vital: It alters the genetic makeup of a population It is important for understanding antibiotic and pesticide resistance, agricultural issues, production, medicines, etc. Organisms adapt to their environment and change over time

7. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Understanding Evolution is vital: Basis of Evolution Individual offspring differs in their genetic characteristics. Some individuals are better suited to adapt to changing environment than others, reproducing more; those can’t adapt to a new environment perish. It is not the strongest that can survive and dominates. It alters the genetic makeup of a population It is important for understanding antibiotic and pesticide resistance, agricultural issues, production, medicines, etc. Organisms adapt to their environment and change over time

8. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings 2009, Feb. 12 th : 200 th Anniversary of C. Darwin (1809.2.12-1882.4.19) Feb. 11-16, Annual Conference of AAAS, Chicago. Theme: “Our Planet and Its Life” Celebrating of Darwinism Nov. 24 th : 150 th Anniversary of ”Origins of Species” (1859) Significance/ Impact: → replaced the concept of a Supreme Being & Creation with a Dynamic Natural Process of Evolution - God derailed. → made Science and Christian Religion incompatible. Strong Influences to K. Marx(1818-1883) : Atheistic Materialism - Communism (“Das Kapital” to Darwin, “Communist Menifesto”) H. Spencer(1820-1903): Biologist/Philosopher Introduced to Sociology & Ethics, “Survival of the Fittest” T. Huxley(1825-1895): Botanists, Advocate, Darwin’s Bulldog F. Nitzsche(1859-1900): Father of Atheistic Existentialism A. Bergsong(1859-1941): Creative Evolution J. Dewey(1859-1952): Pragmatism, Evolutionary Naturalist

9. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Korean Thursday Academy Club Meeting Time: September 24th, 2009 Place: The Korean Center (Buford Highway) Title “Evolution & Mass Extinctions” Speaker: M.-H. Kim, Georgia Perimeter College “Evolution” WGBH(Boston) Video, 2001, Seven Parts Series 1.Darwin’s Dangerous Idea 2.Great Transformation : Assignment 3.Extinction: Assignment 4.The Evolutionary Arms Race 5.Why Sex? 6.The Mind’s Big Bang 7.What about God?

10. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Video Assignment: (Media Section in the Library) “Evolution” WGBH(Boston) Video, 2001, Seven Parts Series 1.Darwin’s Dangerous Idea 2.Great Transformation : Assignment 3.Extinction: Assignment 4.The Evolutionary Arms Race 5.Why Sex? 6.The Mind’s Big Bang 7.What about God?

11. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Why some people do not believe Evolution? How rational are human beings? Blind Belief & Emotions? Human Life Span (100 yrs) : ~5,000 wks Human History : ~5,000 yrs Earth History : ~5,000 M yrs (5 G yrs) Why many educated people does not believe in the Evolution? Their scope of the world is extremely limited, without understanding how old and how vast the universe are → leads to ignorance on the entire World /Cosmos & its vast Scope. Time: Earth History - 4,500 M yrs vs. 0.005 M yrs (a millionth, a negligible fraction) Space: Earth vs Milky Way (10,000km vs. 100,000 ly, 10 17 )

12. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Natural selection shapes organisms In 1858, Darwin and Wallace both proposed natural selection as the mechanism of evolution -Organisms face a constant struggle to survive and reproduce -Organisms tend to produce more offspring than can survive -Individuals of a species vary in their characteristics due to genes and the environment -Some individuals are better suited to their environment and will survive and pass their genes on in their offspring → Survival of the Fittest

13. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Genetic variation Adaptive Trait (Adaptation): a trait that promotes reproductive success Mutations: accidental changes in DNA that may be passed on to the next generation -Non-lethal mutations provide the genetic variation on which natural selection acts Sexual reproduction also leads to variation

14. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Natural selection acts on genetic variation Directional selection = drives a feature in one direction Stabilizing selection = produces intermediate traits, preserving the status quo Disruptive selection = traits diverge in two or more directions If the environment changes, a trait may no longer be adaptive

15. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Evidence of natural selection is everywhere: eg., Galapagos Finches Hawaiian Honeycreepers It is evident in every adaptation of every organism Evident in bacteria and fruit flies in laboratories Selective breeding of animals

16. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Artificial selection The process of selection conducted under human direction - led to the great variety of dog breeds (15,000BP) -Rice with larger/more grains, Corn with larger kernals. Belyaev, Russia, 1950~ : Silver Fox → Domestic Elite Fox (Docile) ~ 35 generations in over 50 yrs, 700 (1996), sell them as pet

17. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Evolution generates biodiversity Biological Diversity: Variety of life across all levels of biological organizations diversity of species, their genes, their populations, their communities Species: a population or group of populations whose members share characteristics and can freely breed with one another and produce fertile offspring ~ 1.8 million species reported (can be higher). Population: a group of individuals of a species that live in the same area Is mule or liger species ?

18. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Speciation produces new types of organisms The process of generating new species -A single species can generate multiple species Allopatric Speciation: species formation due to physical separation of populations -Can be separated by glaciers, rivers, mountains -The main mode of species creation

19. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Allopatric Speciation 1.Single interbreeding population 2.Population divided by a barrier; subpopulations isolated Figure 5.2

20. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Allopatric Speciation (cnt’d) 3.The two populations evolve independently, diverge in their traits. 4.Populations reunited when barrier removed, but are now different enough that they don’t interbreed. Figure 5.2

21. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Causes of Allopatric Speciation Many geological and climatic events can serve as barriers separating populations and causing speciation.

22. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sympatric speciation 1.Lake is formed by melting glacier. 2.2.Lake is colonized by fish. Figure 5.3

23. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sympatric speciation 3.Fish specialize on different habitats and foods, and come to breed separately. 4.Mutually exclusive breeding leads to independent evolution of traits and speciation. Figure 5.3

24. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Another type of speciation Sympatric speciation = species form from populations that become reproductively isolated within the same area -Feed in different areas, mate in different seasons requires many generartions (100~1,000) (Insects, & other animals) -Hybridization (mixing) between two species: (some plants) -Mutations (change in #s chromesomes/DNA) can occur in one generation

25. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Speciation results in diverse life forms Speciation generates complex patterns of diversity Phylogenetic trees (Cladograms) represents the history of species divergence, showing relationships between species Scientists can trace when certain traits evolved Mya 500, Jawless Fish (Sil.) 350, Amphibians (Dev.) 220, Mammals (Tri.) 200, Birds (Jur.) Branch: Speciation 10~50 My

26. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Extinction Species generally evolve from simple to complex and small to big, but the opposite can occur, and some even disappear Extinction : the disappearance of a species from Earth -Occurs when a species cannot adapt quickly enough to a changing environment -Speciation and extinction affect species numbers Cambrian Periods: ~530mya Based on fossils from the Burgess Shale in Canadian Rocky

27. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Extinction is a natural process Extinction is irreversible: once a species is lost, it is lost forever Humans profoundly affect rates of extinction N. America 12kya before human arrival

28. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Some species are more vulnerable to extinction Extinction occurs when the environment changes too rapidly for natural selection to keep up Endemic species = a species only exists in a certain, specialized area -Very susceptible to extinction -These species usually have small populations Many other factors also cause extinction -Severe weather -New species -Specialized species

29. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Earth has had several mass extinctions Background extinction rate: extinction usually occurs one species at a time Mass extinction events: five events in Earth’s history that killed off massive numbers of species at once -50-95% of all species went extinct at one time Humans are causing the sixth mass extinction event -Resource depletion -Population growth -Development

30. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Species’ ranges can be severely restricted Otter salamander on only a few peaksnin Blue Ridge Mountains About 40 U.S. salamander species live on peaks of single mountains

31. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Ecology: Science of relationship between organisms & environments. studied at several levels Ecology and evolution are tightly intertwined Biosphere: the total living things on Earth & the areas they inhabit Ecosystem: communities & the nonliving material and forces they interact with Community: interacting species that live in the same area

32. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Levels of ecological organization Population ecology: investigates the quantitative dynamics of how individuals within a species interact Community ecology: focuses on interactions among species Ecosystem ecology: studies living and nonliving components of systems to reveal patterns -Nutrient and energy flows

33. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Organismal ecology: habitat Habitat = the environment in which an organism lives -Includes living and nonliving elements -Scale-dependent: from square meters to miles Habitat use = each organism thrives in certain habitats, but not in others Habitat selection = the process by which organisms actively select habitats in which to live -Availability and quality of habitat are crucial to an organism’s well-being -Human developments conflict with this process

34. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Organismal ecology: niche Niche = an organism’s use of resources and its functional role in a community -Habitat use, food selection, role in energy and nutrient flow -Interactions with other individuals Specialists = species with narrow niches and very specific requirements -Extremely good at what they do, but vulnerable to change Generalists = species with broad niches that can use a wide array of habitats and resources -Able to live in many different places

35. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Population characteristics All populations show characteristics that help scientists predict their future dynamics Population size : the number of individual organisms present at a given time -Numbers can increase, decrease, cycle or remain the same (end 9/17/08)

36. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Population characteristics Population density = the number of individuals within a population per unit area -High densities make it easier to find mates, but increase competition, and vulnerability to predation -Low densities make it harder to find mates, but individuals enjoy plentiful resources and space (start 9/23/08)

37. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Population characteristics Population distribution (dispersion) = spatial arrangement of organisms within an area -Random – haphazardly located individuals, with no pattern -Uniform – individuals are evenly spaced due to territoriality -Clumped – arranged according to availability of resources -Most common in nature

38. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sex ratio = proportion of males to females -In monogamous species, a 50/50 sex ratio maximizes population growth Age Structure = the relative numbers of organisms of each age within a population -Age structure diagrams (pyramids) = show the age structure of populations Population characteristics: Age Structure Diagram

39. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Birth and death rates Crude birth/death rates = rates per 1000 individuals Survivorship curves = the likelihood of death varies with age -Type I: More deaths at older ages -Type II: Equal number of deaths at all ages -Type III: More deaths at young ages

40. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Four factors of population change Natality = births within the population Mortality = deaths within the population Immigration = arrival of individuals from outside the population Emigration = departure of individuals from the population Growth rate formula = (Crude birth rate + immigration rate) - (Crude death rate + emigration rate) = Growth rate

41. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Exponential population growth Steady growth rates cause exponential population growth -Something increases by a fixed percent -Graphed as a J-shaped curve Exponential growth cannot be sustained indefinitely -It occurs in nature with a small population and ideal conditions

42. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Limiting factors restrain growth Limiting factors = physical, chemical and biological characteristics that restrain population growth -Water, space, food, predators, and disease Environmental resistance = All limiting factors taken together

43. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Carrying capacity Carrying capacity = the maximum population size of a species that its environment can sustain -An S-shaped logistic growth curve -Limiting factors slow and stop exponential growth Carrying capacity changes Humans have raised their carrying capacity by decreasing the carrying capacity for other species

44. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The “J “ curve The “ S “ curve

45. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Perfect logistic curves aren’t often found

46. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

50. Computer simulations predict the future Simulations project trends in population, food, pollution, and resource availability If the world does not change, population and production will suddenly decrease In a sustainable world, population levels off, production and resources stabilize, and pollution declines

51. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Oct 31 st, 2011 7 Billion Jan, 2012 7 Billion

52. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Population density affects limiting factors Density-dependent factors = limiting factors whose influence is affected by population density - Increased risk of predation and competition for mates occurs with increased density Density-independent factors = limiting factors whose influence is not affected by population density -Events such as floods, fires, and landslides

53. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Biotic potential and reproductive strategies vary Biotic potential = the ability of an organism to produce offspring K-selected species = animals with long gestation periods and few offspring -Have a low biotic potential -Stabilize at or near carrying capacity -Good competitors r-selected species = animals which reproduce quickly -Have a high biotic potential -Little parental care

54. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings K-selected vs. r-selected species

55. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Population changes affect communities As population in one species declines, other species may appear Human development now displaces other species and threatens biodiversity -As Monteverde dried out, species from lower, drier habitats appeared -But, species from the cloud-forest habitats disappeared

56. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Challenges to protecting biodiversity Social and economic factors affect species and communities -Nature is viewed as an obstacle to development -Nature is viewed as only a source of resources -Human population growth pressures biodiversity

57. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Preserving biodiversity Natural parks and protected areas help preserve biodiversity -Often, they are underfunded -Ecotourism brings jobs and money to developing areas: Madagascar, some part of Indonesia, Amazon, etc.

58. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Review Which of the following is NOT a part of the process of natural selection? a) Organisms struggle to survive b)Organisms limit the number of young they produce c) Individuals vary in their genetic characteristics d)Some individuals are better suited to their environment than others

59. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Review Disruptive selection would result in which of the following? a)Dogs with black coats evolving whiter coats in colder areas b)Red and white flowers interbreeding, producing pink flowers c)Fish evolving bigger eyes as the water gets muddier d)A population of birds, some with thicker beaks that eat seeds and others with thinner beaks that eat insects

60. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Review Biological diversity includes all of the following, except: a)Species diversity b)Genetic diversity c)Population diversity d)Community diversity e)All of these are included in the concept of biodiversity

61. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Review Sympatric speciation would occur in.... a) One population that mates in May, and another that mates in June b) Two populations separated by the Mississippi River c) Two populations separated by a glacier d) Two populations separated by the Rocky Mountains

62. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Review Which of these species is least vulnerable to extinction? a) A species with a population size of 50 individuals b) A species distributed throughout the United States c) A species that eats only river snails d) A species that lives on mountaintops

63. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Review An ecosystem is defined as: a) The total living things on Earth b) Members of the same population that can interbreed c) Interacting species in an area d) Species and the nonliving material they interact with

64. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Viewpoints Should we care whether a species goes extinct? a)Yes, because all life is important and valuable b)Yes, because we are causing this wave of extinction, so we should fix it c)We should not, because it’s natural d)I don’t care; it really does not affect me

65. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Viewpoints Do you think humans are subject to limiting factors and, ultimately, a fixed carrying capacity? a)Yes, although we have raised the carrying capacity, there are limits to the number of humans the Earth can support b)Yes, but technology will keep raising the carrying capacity, so it’s not much of a problem c)No, humans are no longer constrained by environmental limits, due to our technology and ability to manipulate the environment d)I don’t care; it really does not affect me

66. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Interpreting Graphs and Data Which of the following graphs shows a population that will have fewer individuals in the future? (a)(c)(b)(d)

67. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Interpreting Graphs and Data Which type of distribution is a result of individuals guarding their territory? a) Random b) Uniform c) Clumped d) None of these

68. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings QUESTION: Interpreting Graphs and Data What does this graph show? a)The effects of carrying capacity on population growth b)A population that keeps growing c)The effects of exponential growth d)The effects of increasing carrying capacity

69. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sympatric speciation 3.Fish specialize on different habitats and foods, and come to breed separately. 4.Mutually exclusive breeding leads to independent evolution of traits and speciation. Figure 5.3