Introduction to Biology Lecture 1

1. Introduction to BiologyLecture 1

2. Much of the text material in the lecture notes is from our textbook, “Essential Biology with Physiology” by Neil A. Campbell, Jane B. Reece, and Eric J. Simon (2004 and 2008). I don’t claim authorship. Other sources were sometimes used, and are noted.

3. Outline • Life sciences—a few current areas • Approaches to understanding life • The beginning of our journey • Ecology and ecosystems • Cells and their DNA • The diversity of life • Natural selection and evolution • The processes and culture of science • Words and terms to know • Possible test items

4. A Few Current Areas • Ecosystems and ecology • Human genome project • Reproductive and therapeutic cloning • DNA fingerprinting for legal purposes • Nutrition and physical activity • Medicines derived from plants • Human development and aging • Neurosciences and behavior • Infectious disease spread • Aircraft and spacecraft design • Understanding of the origin of life • Are we alone in the universe?

5. The entire set of genetic instructions an organism inherits is called its genome. • A human genome map was published in 2001 after several years of work at many laboratories. • The map gives biologists a powerful tool to explore the functions of thousands of genes. • Genome have many applications in the biological and medical sciences such as the early identification of genetic diseases and the production of new pharmaceutical drugs. http://www.bioinfo.mbb.yale.edu Human Genome Project

6. Each person has a unique DNA ‘fingerprint’ based on genetic material common to each of the trillions of cells in the human body. • DNA patterns are more similar—the closer people are genetically related to each other. • The probability that two or more people have an identical DNA fingerprint is very small. • DNA fingerprinting has been used to obtain criminal convictions and exonerations, and establish identity and paternity. http://www.ubermorgen.com DNA Fingerprinting

7. http://www.mypyramid.gov • Good nutrition and physical activity are critical to child development, and life-long healthy living. • They are critical to weight management (obesity and overweight rates are very high in the United States). • They can also help in disease prevention (for example, two-thirds of cancer cases are related to lifestyle choices). Nutrition and Physical Activity

8. Medicines Derived From Plants http://sataic.howstuffworks.com http://upload.wikimedia.org Periwinkle, Madagascar Vinblastine is used in some leukemia drugs. Eucalyptus, Australia Menthol is an ingredient in some cough medicines.

9. Medicines Derived from Plants Belladonna, Europe, western Asia, Africa, and North America Atropine is used as an pupil dilator in eye exams. http://upload.wikimedia.org Pacific Yew, Pacific Northwest and British Columbia Taxol is an ovarian cancer drug. http://www.ubcbotanicalgarden.org

10. http://milavia.cjb.net The design of the B-2 aircraft included life support, ozone effects, rapid decompression effects, ejection systems and survivability, NBC protection, acoustic noise cancellation, workload assessment, physical and mental fatigue, anthropometry, visual and acoustic processing, situational awareness, vibration effects, and biodynamic modeling. Aircraft Design

11. First Steps Beyond Our Planet http://www.nasa.gov Ed White, first U.S. spacewalk, Gemini program, 1965

12. Andromeda Galaxy (M31) http:// www.spacepix.net With billions of stars in a galaxy and billions of galaxies in our universe, is life unique to our planet? Bioastronomy and SETI

13. Understanding Life Science, Philosophy, Theology, Art Public domain Paul Gauguin, Where Do We Come From? Where Are We Going To? (1897-98) This course is based on the scientific method—I’m not sufficiently knowledgeable to teach other approaches.

14. Our Journey Begins Here We will soon get started… http://www.thebestlinks.com Human brain—the left cerebral hemisphere, cerebellum, and brainstem are visible. http://www.afacereamea.ro

15. … And Here • A neuron has one axon, some as long as one meter, and typically many more dendrites than shown here. • The human brain has over 10 billion neurons, each with potentially thousands of connections known as synapses. • Neurons are the basic cellular unit of informa-tion processing. • Much research is being performed on neurons and their synaptic connections as they relate to: • Sensations and perceptions • Thoughts and emotions • Fine motor skills and other motor actions • Sleep and altered states of consciousness • Neurological and other medical conditions http://www.dez3d.com An artist’s conception

16. Ecology • Life does not exist in a vacuum—all life forms interact continuously with other living organisms and non-living components in their environments. • Consider plants: • Roots absorb water (H20) and minerals from the soil. • Fungi (mycorrhizae) help the roots absorb nitrogen from the soil. • Leaves absorb carbon dioxide (CO2) from the air. • Chloroplasts absorb sunlight and produce sugars from H20 and CO2. • Leaves release oxygen (O2) into the air. • Roots break-up rocks to help form soil to promote more plant growth.

17. Mycorrhizae http://extension.lastate.edu Fungi living in mutual association with roots are essential to many plants.

18. Ecology • Ecology is the biological study of the relationship between organisms and their environments. • As a scientific discipline, ecology helps us understand the impact of human activities on our planet. http://www.birdforum.net

19. Ecosystems • An ecosystem refers to all organisms and nonliving factors affecting life in an specific area. • Southern California’s ecosystems includes: • Foothills and mountains • High and low deserts • Rivers, streams, and lakes • Marshes, estuaries, and other wetlands • Channel Islands and Pacific Ocean

20. Dynamics • The dynamics of a ecosystem depend on: • Cycling and recycling of nutrients • The flow of energy from sunlight to food producers, and then to consumers • The biosphere is the sum of the dynamic processes in all ecosystems on our planet.

21. Grasslands http://www.bcgrasslands.org

22. The kelp forests off our coast are one of many ecosystems in Southern California. • Kelp is rich in nutrients such as plankton. • The underwater forest provides food and protection to many fish and other marine species. • Biologists study marine life to understand each species and interdependence among species in the oceans. http://www.underwaterplanet.com Kelp Forest

23. Eaton Canyon Falls http://natureathand.com Near Altadena, California

24. Bolsa Chica Wetlands http://api.ning.com Just south of Seal Beach, California.

25. Life’s Basic Unit • Cells are the lowest level of structure that can perform all activities of life. • All life is composed of cells. • Many forms of life are single-cell organisms such as bacteria, amoeba, and protozoa. • Plants and animals are composed of many cells (trillions in humans). • The ability of cells to divide is the basis of reproduction, and for growth and repair of multi-cellular organisms. • All cells use DNA for transmitting information from parents to offspring.

26. Cell Types http://www.visualsunlimited.com Prokaryotic cell Bacteria http://www.visualsunlimited.com Eukaryotic cell Plants, animals, and fungi (animal cell shown) Not to scale: A prokaryotic cell is about 1000 times smaller in volume than a eukaryotic cell.

27. DNA • DNA is found in the nuclei of eukaryotic cells, and central region of prokaryotic cells. • DNA consists of four chemical ‘letters’ (A, G, C, and T). • Human DNA contains about 3.2 billion chemical letters. • DNA is the universal genetic language that serves as the chemical material of genes. • Genes are units of inheritance that transmit information from parents to offspring. Double helix http://www.ks.uiuc.edu

28. Diversity of Life • Biological diversity can be overwhelming with so many plants and animal species. • Species are grouped into smaller numbers of groups to aid in comparison of similarities and differences. • Taxonomy is a branch of biology that names and classifies species into a hierarchical ordering.

29. Domains and Kingdoms • For now, we consider only domains and kingdoms, the broadest units of classification. • New methods such as comparative analysis of DNA have led to ongoing reassessment of the number of kingdoms. • Although debate continues, the general consensus is that the kingdoms belong to three domains of life.

30. Course Focus Life Green represents the primary focus of this course Domain Archaea Domain Eukarya Domain Bacteria Three domains of life Kingdom Fungi Kingdom Plantae Kingdom Protista Kingdom Animalia Four kingdoms of eukarya The domains bacteria and archaea consist of prokaryotic cells; the domain eukarya consists of eukaryotic cells

31. History of Life • The history of life on our planet, which is about 4.5 billion years old, is a changing cast of life forms. • Each species that exists now is one ‘twig’ on a branching tree extending to earlier species and a more remote time. • Similar species sharing a common ancestor represent a recent branch point (for example, brown bears and polar bears). • Less similar species, for example, represent a branch point further back in time (for example, bears and squirrels).

32. Evolution • Mammals, birds, reptiles share a common ancestor even further back in time. • Evidence of this interconnectedness can be found in cell features, DNA, and anatomy. • All life is connected, and the basis for this kinship is known as evolution. http://picasaweb.google.com

33. H.M.S. Beagle Public domain Exploration of Tierra Del Fuego

34. Voyage of Discovery • As a young man, Charles Darwin was invited to be the ship’s naturalist on a hydrographic survey of South America. • The around-the-world expedition lasted almost five years, from 1831 to 1836. • Darwin spent 18 months at sea and over three years on land, much of it in South America. • He kept detailed notes and collected many animal and plant species that were shipped home to England. • Darwin had time to read including books some that anticipated aspects of the theory of evolution.

35. Then and Now Queen Mary 2, 2006 http://upload.wikiemdia.org H.M.S. Beagle, 1831 Both ships have circumnavigated the globe, but only one journey led to a profound change in science and worldview.

36. Discovery • Although Darwin spent just six weeks in the Galapagos Islands, his visit would change biological thinking. • In 1859, Darwin published “On the Origin of the Species” his first work on natural selection and evolution. Darwin’s later microscope that he used to study plant and barnacle specimens. http://www.hps.cam.ac.uk

37. Environmental Adaptation • Darwin regarded adaptation to the environment and origin of new species as closely related processes. • For example, populations of a species separated by a geographical barrier diverge in appearance over many generations as they adapt to different local conditions. • Finches arrived in the Galapagos Islands from South America 2-3 million years ago. • Fourteen finch species were found on individual islands in the island chain. • Darwin noted major differences in beak structures. • The beaks evolved as adaptations to the types of foods available on each island.

38. Finch Beaks Public domain Finches in the Galapagos Islands have vastly varying beaks.

39. Darwin’s Finches Small tree finch Medium tree finch Large tree finch Mangrove finch Woodpecker finch Large ground finch Medium ground finch Small ground finch Large cactus ground finch Cactus ground finch Vegetarian finch Thin beak Large, powerful beak Cactus-flower- eaters Seed-eaters Insect-eaters Bud-eater Green warbler finch Gray warbler finch Thin beak Sharp-beaked ground finch Ground Finches Tree Finches Warbler Finches Common Ancestor, South American Mainland

40. Natural Selection • Natural selection is based on two principals and a conclusion • Principal 1: Overproduction and struggle for existence—any population of a species can produce many more offspring than the environment can support. • Principal 2: Individual variation—individuals in a population vary in heritable traits, and no two individuals are exactly alike. • Conclusion: Unequal reproductive success—in the struggle for existence individuals with traits best adapted to the environment will have the greatest reproductive success. • Traits that enhance survival and reproduction will be more highly represented in the next generations.

41. Meet the Beetles 2. Birds eliminate individual beetles (usually white shells) 1. Beetle population has a specific inherited trait (white or dark gray shells) + Insect-Eating Birds These imaginary beetles typically live on a dark-colored tree bark 4. Traits that enhance survival and reproductive success predominate 3. The survivors reproduce

42. Descriptive Science • Science seeks natural causes for natural phenomena based on observation and measurement. • Science cannot prove or disprove the existence of the supernatural and if they have any effect on natural phenomena. • The goal of descriptive, or discovery, science is to understand the structure of nature. • Darwin’s study of the plants and animals on the Beagle was descriptive science. • Descriptive science can lead to important conclusions based on inductive reasoning.

43. Inductive Reasoning • Inductive reasoning flows in the direction of specifics to the general, or from observations to conclusions. • A conclusion is a generalization summarizing many observations, such as “all organisms consist of cells.” • Inductive reasoning has played an important in the accumulation of biology knowledge.

44. Classification http://www.digitastar.net A scientist’s sketch of diatoms.

45. Hypothesis-Based Science • Hypothesis-based science is based on deductive reasoning that flows from the general to the specific. • Results (predictions) are extrapolated if the premises are found to be true. • Premise 1: If all organisms are made of cells • Premise 2: And humans are living organisms • Deductive prediction: Then humans are composed of cells • The approach is known as hypothesis testing, the cornerstone of scientific experimentation.

46. Hypothesis Testing Observations Questions Hypothesis Prediction Test supports hypothesis; make additional predictions and test them. Test does not support hypothesis; revise or reject hypothesis, or develop a new one. Test (Experiment or study)

47. A Tale of Two Snakes Eastern Coral Snake http://www.sciencemore.com Scarlet Kingsnake Both species of snake live in the eastern Carolinas http://fwie.fw.vt.edu

48. Experiment • Observation: The venomous eastern coral snakes and non-venomous scarlet kingsnake both have red, yellow, and black rings. • Question: Why do scarlet kingsnakes look similar to eastern coral snakes? • Hypothesis: Mimicry helps protect scarlet kingsnakes from predators. • Prediction: Predators will confuse scarlet kingsnakes with eastern coral snakes. • Test: Compare the number of animal attacks on ringed versus brown artificial snakes. • Test outcome: The brown artificial snakes are attacked by birds and other animals about five times more often than ringed artificial snakes.

49. Results Details of the experiment are described in the textbook. 100% 84% Percentage of Total Attacks 50% 16% 0% Artificial Snakes In Plain Brown Artificial Snakes With Colored Rings

50. Culture of Science • Science is dependent on observations and measurements. • Ideas or hypotheses are testable by experiments that others can repeat. • Scientists focus on evidence, and often have a high level of inquiry and skepticism. • Information is shared in many ways including in meetings, publications, and the internet. • This sharing contributes to the progressive and self-correcting qualities of science. • The theories that scientists develop consolidate observations and have predictive power.