BSC 2010

1. BSC 2010 Suzanne Butler 1271-9 (305)237-8118 sbutler@mdcc.edu

2. Textbooks • Required text Biology, 6th ed. Neil Campbell and J. Reese. 2002. Benjamin Cummings. • Optional Textbook Chemistry for Biology Students, 7th ed. by George Sackheim

3. Introduction: Ten Themes in the Study of Life Chapter 1

4. Biology Scientific study of life Lays the foundation for asking basic questions about life and the natural world

5. Evolution of Biology As a Science • Through the Middle Ages • Major scientific discoveries were made in early Egypt, Babylonia, and Greece • Between 200 and 1200 AD there were almost no important scientific advances • No real distinction made between science and theology • Not much questioning of anything

6. Evolution of Biology As a Science • Intellectual Reawakening in Europe • Albertus Magnus and Thomas Aquinas • Theologians and philosophers teaching in Paris • Prepared the way for more independent development of science • Roger Bacon • Called for an end to unthinking acceptance of classical writings such as Aristotle “Cease to be ruled by dogmas and authorities; look at the world.”

7. Evolution of Biology As a Science • New Era in the Physical Sciences • Copernicus and Galileo • said the earth was not the center of the universe • Led to the conclusion that the earth can be understood in terms of universal laws • Isaac Newton • Discovery of the Laws of Gravitation • explanations in 1685 of the movements of planets • Caused a revolution in human thought • Moved physical science into new era

8. Evolution of Biology As a Science • New Era in Biological Sciences • Did not begin until the middle of the nineteenth century • Began when Pasteur finally disproved “spontaneous generation” • Darwin’s work on evolution was the beginning of the same kind of revolution in biology that Newton’s began in physics

9. Spontaneous Generation • Prevailing scientific view for over 300 years • Organisms are regularly generated from non living materials • Put Garbage in the street • Rats generate spontaneously • Hang meat in open stalls • Maggots appear • Put broth on the window sill to cool • Bacteria grow

10. DisprovingSpontaneous Generation • Francesco Redi • performed an experiment to check whether maggots really came from decaying meat • placed meat in a number of jars and covering half of them with fine gauze while leaving the others uncovered • Maggots developed only on the meat in the uncovered jars

11. Argument in Support of Spontaneous Generation • the belief in spontaneous generation remained strong, and even Redi continued to believe it occurred under some circumstances • invention of the microscope only served to enhance this belief • a whole new world of organisms that appeared to arise spontaneously • John Needham • knew that boiling killed microorganisms • boiled chicken broth, put it into a flask, sealed it, and - sure enough, microorganisms grew • claimed victory for spontaneous generation

12. Disproving Spontaneous Generation • Lazzaro Spallanzani • almost one hundred years after Redi’s experiments modified Needham’s experiment

13. Argument Supporting Spontaneous Generation • Spallanzani had only proven that spontaneous generation could not occur without air.

14. DisprovingSpontaneous Generation • Louis Pasteur • Boiled nutrient mixture in flask with long s-shaped necks • Almost all flasks treated this way remained free of bacterial growth as long as the neck was unbroken • When Pasteur tilted the flask so that the broth reached the lowest point in the neck, where any airborne particles would have settled, the broth rapidly became cloudy with life • Concluded that microorganisms were brought into flask on dust particles rather than generated from the nutrient mixture

16. Evolution of Biology As a Science • New Era in Biological Sciences • Did not begin until the middle of the nineteenth century • Began when Pasteur finally disproved “spontaneous generation” • Darwin’s work on evolution was the beginning of the same kind of revolution in biology that Newton’s began in physics

17. The Evolution of Evolution • Cuvier • Catastrophism • One time creation • Successive catastrophes caused some to become extinct and others to fluorish • Lamarck • Proposed inheritance of acquired characteristics • Lyell • Princilpes of Geology, 1830 • Proposed that geological forces still operating could account for the changes that were seen in the earth’s surface • Earth not in final form at creation, but steadily undergoing change

18. Charles Darwin • At 8 years old he was intrigued with the natural world. • He studied medicine but could not stomach surgery • He then studied to be a clergyman, but spent his time with scientists while at Cambridge

19. Darwin’s Voyage • At age 22, Charles Darwin began a five-year, round-the-world voyage aboard the Beagle • In his role as ship’s naturalist he collected and examined the species that inhabited the regions the ship visited

20. Voyage of the Beagle EQUATOR Galapagos Islands

21. Darwin Wolf Pinta Genovesa Marchena Santiago Bartolomé Seymour Rabida Baltra Pinzon Fernandia Santa Cruz Santa Fe Tortuga San Cristobal Española Floreana GalapagosIslands Volcanic islands far off coast of Ecuador All inhabitants are descended from species that arrived on islands from elsewhere Isabela

22. Darwin’s Observations • In Argentina, Darwin observed fossils of extinct glyptodonts • Animals resembled living armadillos • In the Galapalos Islands he saw strange iguanas, turtles, and mocking birds that varied from one island to another

23. Galapagos Finches • Darwin observed finches with a variety of lifestyles and body forms • On his return he learned that there were 13 species • He attempted to correlate variations in their traits with environmental challenges

24. Diversification of finches on the Galápagos Islands

25. Darwin Begins to Understand • The Galapagos finches were related to an ancestral species that could be found on the mainland of SA hundreds of miles to the east • Members of that ancestral species had come to the Galapagos by air then fanned out to separate islands • They had diverged over time into separate species • Still had no mechanism for driving this “descent with modification”

26. Malthus - Struggle to Survive • Thomas Malthus, a clergyman and economist, wrote essay that Darwin read 2 years after his return to England • Argued that as population size increases, resources dwindle, the struggle to live intensifies and conflict increases

27. Darwin’s Theory • Rejects the notion that living creatures are immutable products of a sudden creation. • A population can change over time when individuals differ in one or more heritable traits that are responsible for differences in the ability to survive and reproduce

28. Figure 1.15 Natural selection

29. Alfred Wallace • Naturalist who arrived at the same conclusions Darwin did • Wrote to Darwin describing his views • Prompted Darwin to finally present his ideas in a formal paper

30. On the Origin of Species • Darwin’s book • Published in 1859 • Laid out in great detail his evidence in support of the theory of evolution by natural selection

31. Two Parts of Darwin’s Theory • Descent with modification • Change is the rule rather than the exception • Organisms living today have descended by gradual changes from ancient ancestors quite unlike themselves • Natural selection determines the course of the change • It is a completely mechanistic process without conscious purpose or design • individuals differ in one or more heritable traits that are responsible for differences in the ability to survive and reproduce

32. Populations Evolve • Biological evolution does not change individuals • It changes a population • Traits in a population vary among individuals • Evolution is change in frequency of traits

33. Some properties of life

34. How Do We Know If It is Alive? • Metabolism • Taking in and digesting food • Assimilating digested food • Respiration • Excretion • Non-living things do not derive energy by taking in or transforming foreign matter.

35. Energy utilization

36. How Do We Know If It is Alive? • Growth and Development • Organisms develop new parts between or within older parts • Non-living things can grow only by addition of material to the outside.

37. Growth and development

38. How Do We Know If It is Alive? • Irritability • Response to environmental stimuli • Many forms • May not be proportional to stimulus • Organism not usually permanently altered by the stimulus • Non-living things may react to stimuli • Always a quantitative relationship between the stimulus and the effect

39. How Do We Know If It is Alive? • Reproduction • Each kind of living thing reproduces itself in kind • Information needed to develop and reproduce is segregated within the organism • Information needed to develop and reproduce is passed to offspring • Non-living things do not reproduce

40. Reproduction

41. How Do We Know If It is Alive? • Evolution and Adaptation • Groups of organisms change over time • Changes make organisms more able to live in the particular local environment • Non-living things do not change nor adapt to the environment

42. How Do We Know If It is Alive? • Order • All organisms are highly organized • Maintain that organization by expending energy • Each type usually has definite form and shape • All organisms are composed of cells • Non-living things do not maintain their organization by expending energy

43. Order

44. Unity of Life All organisms: • Are composed of the same substances • Engage in metabolism • Sense and respond to the environment • Have the capacity to reproduce based on instructions in DNA

45. Figure 1.5 The genetic material: DNA

46. Diversity of Life • Millions of living species • Additional millions of species now extinct • Classification scheme attempts to organize this diversity

47. Five Kingdoms

48. Classifying life

49. Structure and Function • Correlated at all levels of life • A bird’s shape and it’s skeleton • Make flight possible • Aerodynamic shape of wing • Honeycombed construction of bone • A cell’s form fits its specialized function • Nerve cells have long extensions that transmit signals • At the sub-cellular level • Inner membrane of mitochondrion is folded to provide more surface area

50. Form fits function