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Class Notes for Exploring Biological Anthropology: The Essentials, 4th Edition

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    Instructor’s Manual to accompany E XPLORING B IOLOGICAL A NTHROPOLOGY The Essentials Fourth Edition CRAIG STANFORD University of Southern California JOHN S. ALLEN University of Southern California SUSAN C. ANTÓN New York University

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    iii CONTENTS Chapter 1 . Introduction: What I s Biological Anthropology? 1 Chapter 2 . Origins of Evolutionary Thought 5 Chapter 3 . Genetics: Cells and Molecules 1 1 Chapter 4 . Genetics: From Genotype to Phenotype 1 8 Chapter 5 . The Forces of Evolution and the Formation of Species 2 5 Chapter 6 . Human Variation: Evolution, Adaptation, and Adaptability 3 2 Chapter 7 . The Primates 40 Chapter 8 . Primate Behavior 4 7 Chapter 9 . Geology and Primate Origins 5 3 Chapter 1 0 . Early Homini n s and Australop i thecus 6 4 Chapter 1 1 . Rise of the Genus Homo 7 2 Chapter 1 2 . Archaic Homo Sapiens and Neandertals 8 0 Chapter 1 3 . The Emergence , Dispersal , and Bioarchaeology of 89 Homo Sapiens Chapter 1 4 . Evolution of the Brain and Behavior 9 8 Chapter 1 5 . Biomedical and Forensic Anthropology 1 0 7

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    1 . CHAPTER ONE WHAT IS BIOLOGICAL ANTHROPOLOGY? LEARNING OBJECTIVES After reading and carefully considering Chapter One, students should be able to: ● 1.1: Identify the subfields of Anthro pology and explain their applications to the study of the human species. ● 1.2: Explain the subfields within biological anthropology and discuss how they try to answer key questions about the human species. ● 1.3: Review the development of biological anthropology in the United States, including change in focus over time. LEARNING OBJECTIVE SUMMARY ANTHROPOLOGY AND ITS SUBFIELDS 1.1 Identify the subfields of Anthro pology and explain their applications to the study of the human species. • Anthropology is the study of humankind in a cross - cultural perspective. • Anthropologists study cultures in far - flung places, and they also study subcultures in our own society. • Anthropology has four subfields. THE SCOPE OF BIOLOGICAL ANTHROPOLOGY 1.2 Explain the subfields within biological anthropology and discuss how they try to answer key questions about the human species. • Biological anthropology is one of Anthro pology ’ s four subfields, along with archaeology, cultural anthropology, and linguistic anthropology. • It is the study of humans as biological creatures: where we came from, our evolution, and how our biology interacts with our culture today. THE ROOTS OF MODERN BIOLOGICAL ANTHROPOLOGY 1.3 Review the development of biological anthropology in the United States, including its change in focus over time. • Evolution by natural selection is the principle by which biological anthropologists understand the place of humans in the natural world. • Biological anthropology seeks to answer a few basic questions: What does it mean to be human? How did we become who we are today? How does our biological past influence our lives in the environments of the present? What is the place of human beings in nature? LECTURE OUTLINE I. Introduction A. Links between biologists in different subfields B. Biological anthropologists try to understand details of evolution 1. How do they shape who we are today? 2. Debzhansky: “ Nothing in biology makes sense except in the light of evolution. ” C. The evolutionary process is slow and inefficient II. Anthropology and its subfields A. Anthropology is the study of humankind in all its forms

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    2 . 1. Distinguished by its cross - cultural, holistic nature 2. Culture: the sum total of learned traditions of a group of people (e.g. , language) 3. Debate over interplay of biology and culture B. Other subfields of anthropology 1. Cultural anthropology: the study of human societies in a cross - cultural perspective a. Ethnology: a subfield of cultural anthropology, the study of behavior within human societies 2. Linguistic anthropology: the study of the form, function, and social context of language 3. Archaeology: the study of how people used to live, based on artifacts they left behind a. Historical archaeologists study past civilizations that left a written record III. The Scope of Biological Anthropology A. Paleoanthropology: the study of the fossil record for humankind 1. Includes fossilized remains with the most direct physical evidence of human ancestry 2. Famous examples include Lucy or the Peking Man 3. Discovery of new human fossils every decade or so 4. Research takes place in the field as well as in museums and laboratories 5. Comparisons between extinct and living forms (e.g., presence of canine teeth) 6. Tree with many branches has replaced linear view of human evolution B. Skeletal Biology and Human Osteology 1. Osteology: study of the skeleton 2. Identify what sort of animal the fossil/fragment was in life 3. Keen spatial sense of how jigsaw - puzzle - like array fits together 4. Among the first generation of biological anthropologists 5. Relationship between genetics, human growth and stature, and geographic variation 6. Skeletal anthropology: includes patterns and processes of human growth, physiology, and development C. Paleopathology and Bioarchaeology: the study of disease in ancient human populations 1. Goes hand - in - hand with the study of human remains in archaeological context 2. Study effects of trauma, epidemics, nutritional deficiencies, and infectious diseases D. Forensic anthropology: study of the identification of skeletal remains 1. Includes means by which an individual died 2. Applications in historical study and criminal investigations E. Primatology: study of the anatomy, physiology, behavior, and genetics of both living and extinct monkeys, apes, and prosimians 1. Best known through the work of Jane Goodall and Dian Fossey 2. Desire to learn more about patterns of behavior 3. Learn about how evolution molded the human species F. Human Biology: study of human growth and development, adaptations to environmental extremes, and human genetics 1. Nutritional anthropologists study diet, culture, and evolution 2. Biological and cultural forces 3. Human variation gives clues to migrations of earlier peoples 4. Biocultural anthropology and biomedical anthropology: expressions of human diseases 5. Molecular anthropology: genetic approach to human evolutionary science IV. The Roots of Modern Biological Anthropology A. Evolutionary perspective made many old debates about human origins irrelevant 1. Result of interrelations of genetics and environment B. Physical anthropology appeared as discipline in second half of the nineteenth century C. Not simply shot and dissected: synthesis of genetics, anatomy, ecology, and behavior D. New dating techniques spurred paleoanthropology E. Today, a wide variety of approaches

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    3 . LECTURE AND DISCUSSION TOPICS Each of these topics is intended to generate ideas either for lectures or for discussion in the classroom. For most topics, students should be able to respond and participate in discussions based solely on reading the text. For others, students may need further reading or other forms of information to develop some personal perspective and become equipped to make independent decisions about the topics. 1. D iscuss the connection between biology and evolution and how that connection helps tie the subfields of anthro pology together. It might be helpful to examine all the subfields from an evolutionary perspective and tie them to biological anthropology. 2. Include a brief lecture examining the scientific climate in which anthro pology was born. There were recent discoveries both of fossil hominids and in a framework for the natural selection of inherited traits. Franz Boas would have been examining these new finds and theories to help shape his understanding of the complexity of humanity and how it might be understood. 3. Include a lecture on how the subfields evolved. There were not always four; classically, Anthro pology as a field consisted only of cultural and biological. Why the additions? Examine the question from the perspective of the history of anthro pology. 4. Include a lecture on applied science. Certain subfields, like f orensic a nthropology, are focused on more time - sensitive products than is typical of academia but still possess strong research components. CLASSROOM ACTIVITIES 1. Have students break into groups and assign them a specific sub - field. They should then be able to discuss the aspect of humanity that their sub - field focuses on and how it also ties back to the goals of a nthropology as a whole. 2. Have students discuss their thoughts on the sub - fields in terms of how the media and popular writing has depicted them. Sometimes we are affected by the fictional depiction of anthropologists (archaeologists in particular) and that can color our understanding of the field. Examining the sub - fields from that perspective may help untangle fact from fiction. 3 . Invite a practitioner of one of the subfields into class and have them talk about the work they do. Then ask students to explain how that work ties back into the larger description and definition of anthro pology as it has been discussed in class. 4. Invite a nonanthropologist to class who has a research focus in a related field, such as biology, and have them discuss their work. Then ask the students to comment on how this work can contribute to research goals in anthro pology. RESEARCH AND WRITING TOPICS 1. Have students choose an early founder of anthro pology and write a short biographical sketch of the person. Then have them discuss how their background facilitated or led them to their area of anthro pological research. 2. Have students discuss different ways that anthropological data is used today. Are there any industries that use it? Are there any practical applications of this data? 3. Have students choose an important discovery from one of the subfields and write about its impact on that subfield and for the discipline of anthro pology.

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    4 . 4. Have students choose a film or TV show that focuses on a subfield of anthro pology. They should write a paper that examines whether or not the characters are depicted accurately and if any true aspects of the field are used in the storytelling. REVEL RESOURCES AND ACTIVITIES Activity: Subfields of B iological A nthropology Video: Primatology

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    5 . CHAPTER TWO ORIGINS OF EVOLUTIONARY THOUGHT LEARNING OBJECTIVES After reading and carefully considering Chapter Two , students should be able to:  2 .1: Explain how science differs from other ways of understanding the world.  2 .2: Explain the contributions of earliest scholars before Darwin to the development of evolutionary theory.  2 .3: Identify the contributions of the thinkers just before Darwin ’ s time and how they helped him formulate his ideas.  2 .4: Summarize the ideas of Charles Darwin and how he developed them.  2 . 5 : Explain the difference between science and faith - based explanations of life. LEARNING OBJECTIVES SUMMARY WHAT IS SCIENCE? 2.1 Explain how science differs from other ways of understanding the world. • Science is a progressive, self - correcting, evidence - based way of understanding the world. • Faith ’ s evidence is the Bible, and it is impervious to evidence and hypothesis testing. THE EARLY THINKERS 2.2 Explain the contributions of earlies t scholars before Darwin to the development of evolutionary theory. • Carol von Linnaeus revolutionized the study of living things by classifying them according to similarities in form. THE ROAD TO THE DARWINIAN REVOLUTION 2.3 Identify the contributions of the thinkers just before Darwin ’ s time and how they helped him formulate his ideas. • Many pre - Darwinian thinkers accepted evolution and put forward theories for the mechanism. • Darwin was influenced by three eminent French natural historians: Comte de Buffon, Georges Cuvier, and Geoffroy Saint - Hilaire. • Lamarck proposed that the use of a trait could influence an offspring ’ s phenotype in the next generation. Darwin showed that change could occur across generations based only on the selective retention of some traits and the filtering out of others. THE DARWINIAN REVOLUTION 2.4 Summarize the ideas of Charles Darwin and how he developed them. • Charles Darwin spent his life thinking and writing about evolutionary change, and he developed the theory of evolution by natural selection to account for it. • Alfred Russel Wallace was a contemporary of Darwin and codiscoverer of the theory of evolution by natural selection. • Natural selection can occur only if a trait can be inherited, if there is variation within a population, and if there is pressure from the environment. SCIENCE AND CREATIONISM 2.5 Explain the difference between science and faith - based explanations for life.

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    6 . • Intelligent design creationism is a recent attempt to repackage old creationist ideas in a way that argues for a divine force without calling it God. LECTURE OUTLINE I. Introduction A. Battles between teaching evolution and creationism 1. The Dover Case & t he Scopes Trial B. Life on Earth as unchanging 1. The scale of evolution 2. Uses of the term theory II. What is Science? A. The scientific method 1. Developing a hypothesis: a preliminary explanation of a phenomenon 2. Moving from observation to data to experiment 3. Experiments: the testing of a hypothesis, before the researcher can truly stake his or her claim B. Science is an empirical process 1. Theories are self - correcting a. Contradicting claims can be examined and resolved by examining data b. Earlier mistakes can always be corrected 2. Theories are falsifiable a. Science uses paradigms, conceptual frameworks for understanding a body of evidence b. Changing paradigms is a long, slow process III. The Early Thinkers A. The R oots of M odern S cience 1. The concept of immutability of species a. For centuries, life was thought of as an orderly, hierarchical ladder 2. The church set the doctrine during the Middles Ages a. Fixity of species was the spiritual, legal, and political norm b. Aristotle ’ s hierarchical Great Chain of Being 3. Changes came about during the Renaissance a. Scholar ’ s rediscovered ancient Greek and Roman knowledge and their approach to science became more “ modern ” b. Advances in human anatomy changed the way scholars looked at the human body 4. T he C hurch ’ s power a. Abiding belief in single creation: James U s sher ’ s biblical calculations of the age of the Earth B. Linnaeus and the Natural Scheme of Life 1. John Ray first used the terms genus and species 2. Carolus Linnaeus built on Ray ’ s writings to develop his taxonomy a. Sorting organisms into categories helped to establish their relationships b. Tax a based on organisms ’ similarities c. Linnaean system of taxonomy uses binomial nomenclature, or a two - level genus - species label IV. The Road to the Darwinian Revolution A. In the eighteenth and early nineteenth centuries, European natural historians focused on explaining the diversity of life B. Three prominent French philosophers 1. Comte de Buffon a. Accepted general notion of biological change b. Observed that animals in new climates often change in response to environments c. Claimed that New World animals were weaker and smaller than Old World counterparts 2. Georges Cuvier a. Steadfast opponent of theory of evolution

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    7 . b. Advocated catastrophism to explain presence of dinosaur bones and changing organisms c. Catastrophism: the theory that there have been multiple creations interspersed by great natural disasters i. Noah ’ s flood 3. Geoffroy Saint - Hilaire a. An anatomist and a strong advocate of evolutionary change b. D ebated creationist Cuvier c. Supported Lamarck ’ s explanation for the mechanism of evolution C. Jean - Baptiste Lamarck 1. His 1809 theory of inheritance of acquired characteristics (Lamarckianism) a. That organisms make adjustments to their environment during their lifetime b. Relies on the concept of need and use c. Animals who swim frequently would theoretically have offspring who could swim well d. In his theory, adjusted traits would be passed down to offspring 2. His major breakthrough was the relationship between organism and environment a. Theory ’ s central error is that evolution would take place in lifetime of individual organism b. Had no knowledge of genes c. Natural antecedent to Darwin ’ s theory D. The Uniformitarians: Hutton and Lyell 1. James Hutton a. Father of modern geology b. Saw clear evidence of past worlds in rock formations c. Uniformitarianism: same gradual geological process we observe today was operating in the past 2. Charles Lyell a. Proponent of uniformitarianism b. Friendship with Darwin influenced evolutionary theory c. Earth ’ s history understood in context of its ancient changes V. The Darwinian Revolution A. Da rwin ’ s e arly years 1. Born into life of affluence 2. Left medical studies at University of Edinburgh 3. Studied for the ministry at Cambridge University a. Deeply influenced by his professor, botanist John Henslow B. The Galapagos 1. Five year voyage as the “ gentleman ” amateur naturalist aboard the HMS Beagle (1831 – 1836) 2. Explored South America, Australia, and Africa 3. Significant observations in the Galapagos Islands a. Each island had own species of finch with different physical traits b. Darwin did not immediately formulate theory c. These thirteen species of finch studied by John Gould in London 4. Gould ’ s study gave Darwin first insight into : a. Biogeography: the distribution of animals and plants on E arth b. Adaptive radiation: the diversification of one founding species into multiple species and niches c. Darwin referred to these biological changes as natural selection: differential reproductive success over multiple generations C. Refining the Theory of Evolution by Natural Selection 1. Spent years in study at home in England 2. Drew parallels to local breeders ’ artificial selection in breeding livestock a. S ame essential process, the selection of genes, as in natural selection b. K ey difference is that natural selection does not have conscious goals 3. Galvanized to publish after receiving Alfred Wallace ’ s manuscript

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    8 . a. L ower - class Wallace was a field biologist b. H ad developed own theory of evolution by natural selection 4. Darwin ’ s publication, On the Origin of Species , enjoyed widespread success and sales 5. Observations and Deduction s in On the Origin of Species a. Observation 1: Malthus ’ s concept that all organisms have the potential for explosive growth b. Observation 2: In nature, populations are roughly stable c. Deduction 1: There must be a struggle for existence i. B ullfrog ’ s offspring survival rate d. Observation 3: Nature is full of variation, every individual unique e. Deduction 2: Some variations must be favored, and some disfavored, in natural selection 6. Natural selection centers on reproductive success a. Social theorist Herbert Spencer ’ s phrase “ survival of the fittest ” misleading b. Darwinian fitness: reproductive success 7. In order for natural selection to be at work: a. Trait in question must be inherited b. Trait in question must show variation between individuals c. The environment must exert some pressure on organisms 8. Evolution occurs in populations , not individuals a. Natural selection acts on mutations in a population VI. Science and Creationism A. Basis of Creationism 1. Book of Genesis as an alternative to science 2. Argu ment that Earth is very young 3. Sedimentary evidence of extinct animals as the product of Noah ’ s flood B. Reliance on faith 1. Old Testament not testable evidence 2. Must be accepted without scientific method C. Political aspects of c reationism 1. Legal battles to teach c reationism in schools a. Louisiana ’ s unconstitutional disclaimer on evolution b. A tlanta ’ s “ alternatives to evolution ” D. Creation science 1. Arguments against evolution a. Emphasize gaps in the fossil record b. Denial of science rather than science itself c. Includes Intelligent Design: proposes that natural selection cannot account for the diversity and complexity of form and function in nature E. Mandated division between church and state in U.S. Constitution 1. Rights of religious faiths or lack of faith equally respected 2. Science classrooms intended to train scientific thinking LECTURE AND DISCUSSION TOPICS Each of these topics is intended to generate ideas either for lectures or for discussion in the classroom. For most topics, students should be able to respond and participate in discussions based solely on reading the text. For others, students may need further reading or other forms of information to develop some personal perspective and become equipped to make independent decisions about the topics. 1. Lecture on evolution — Consider a lecture using some of the fossil evidence that Darwin had available when he was forming his theory. Discuss how fossils can show change through time. This would also be a way of introducing recent finds such as Homo naledi fossils from South Africa.

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    9 . 2. Perhaps incorporate a discussion of some of the recent findings about cloning and what this contributes to our understanding of evolutionary processes. Students will likely be interested in the ethical issues involved in manipulating evolutionary processes. 3. Consider a lso a discussion of the scientific method in this chapter, including its procedures and limitations. It can only deal with questions that are potentially or actually repeatable. Its steps are: (1) observation; (2) question or problem; (3) hypothesis/null hypothesis; (4) d ata collection / experimentation ; and (5) formation of a conclusion. Stress the equal importance of honest , effective methodology and conclusion formation. Also explain that the scientific method is a continuous process, and these five steps repeat with major/minor modifications to the hypothesis. Describe the process of theory formation, a hypothesis supported by a large body of observations confirmed by many independent investigators. 4. As part of this lecture, describe how good theory formation (1) explains or shows relationships among facts; (2) simplifies; (3) clarifies; (4) grows to relate additional facts , which means it is always tentative in scope; (5) predicts new facts and relationships; and (6) does not explain too much. Theory becomes a scientific law if it possesses a high degree of certainty and is widely accepted within the scientific community. Stress to students that a scientific “ fact ” is an accurate description of an object or event based on what we know and what we know how to do. It is not an absolute finality. 5. Perhaps take the opportunity to discuss patterns of deductive and inductive logic. Talk about proof and rigor of proof in science. Be sure to emphasize that when we extrapolate from a scientific theory, it is only supposition, not scientific fact. 6 . A lecture about the history of biology as a field of study might be useful , especially as it relates to the path that Darwin took to introduce his idea to the larger community of scientists. One way to e xamine this path is to look at the historical influences that helped shape biological theory immediately before Darwin and Wallace published their works. 7 . Natural selection provides direction to evolutionary change, yet students often have trouble grasping the concept. Discuss examples of natural selection in detail and explore what “ fitness ” means in evolutionary terms. 8 . Examine the influence of the Church on all science in Darwin ’ s time. Discuss examples of how the C hurch at that time regarded change in species and how that position has changed over time. CLASSROOM ACTIVITIES 1. Have students share their cosmologies and origin myths. Talk about similarities and differences in the ones expressed. As always with such discussions, it is necessary to establish a neutral atmosphere, with acceptance and patience for hearing others ’ ideas. 2 . Have your students read the 1858 paper titled , “ On t he Tendency of Varieties to Depart Indefinitely from the Original Type ” by Alfred Wallace. Students should then compare Wallace ’ s conclusions to Darwin ’ s ideas about natural selection. Have them report their findings. 3 . Discuss the students ’ various religious and nonreligious beliefs about the origins of life. Emphasize again the importance for tolerance in listening to other students ’ points of view. Further discuss the concept of Intelligent Design and how it is an intellectual, but not scientific, approach to explain evolutionary change. 4 . Darwin used geology to help him make the case for descent with modification. Have students discuss how thoughts on the age of the E arth in Darwin ’ s time period kept many from believing th at such changes to species could even occur.

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    10 . 5 . Ask students to describe what kinds of species they see around them, at school or around their homes. Can they use any to talk about evolution? Have them list characteristics that might have been influenced by natural selection. RESEARCH AND WRITING TOPICS 1. Have students research an origin myth that is not their own using library sources and/or interviewing. Have them compare and contrast this myth with their own and explain how they reconcile competing claims of truth. This may be presented in written or oral form. 2. Have students complete written or oral biographical reports on one of the following men and how their scientific ideas contributed to Western thought: Georges Cuvier, Comte de Buffon, James Hutton, Charles Lyell, Charles Darwin, Jean - Baptiste Lamarck, or Alfred Russel Wallace. 3. Have students outline the steps Darwin used to describe how descent with modification worked. They should try to describe how he argued for the veracity of his findings and the evidence he used. 4 . Have your students research scientific creation, evolutionism, theistic evolutionism, and creationism. In written or oral reports, or in a debate, have students defend a position they do not hold. Monitor, using a brief essay or opinion poll, how the students ’ opinions may have changed based on what they have learned in the chapter. 5. Invite proponents of biological evolutionism, scientific creationism, and theistic evolutionism/creationism into your class. After each gives a short presentation of his or her views, they could engage in a debate in which students could participate. Discuss the Scopes trial and the controversy that marks the publication of biology textbooks in certain states. 6 . Have students research the origins of Systema Natura , written by Linnaeus , and explain how it contributed to the development of modern biology. Students should understand how the nomenclature helps with information organization, which is critical to science. REVEL RESOURCES AND ACTIVITIES Activity: The Scientific Method Reading: Happy Birthday Linnaeus Activity: Lamarckian and Darwinian Views of Evolution Activity: Explore Darwin ’ s voyage on the HMS Beagle Reading: Testing Natural Selection

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    . 11 CHAPTER THREE GENETICS: CELLS AND MOLECULES LEARNING OBJECTIVES After reading and carefully considering Chapter Three , students should be able to:  3 .1 : Recognize how genetics can be studied at different biological levels and describe each of those levels.  3 .2 : Understand how the cell is the basic unit of life on Earth, and be able to label the components of a generic cell.  3 .3 : Compare and contrast: DNA/RNA, translation/transcription, base/codon, genes/chromosomes, and mitosis/meiosis.  3 .4 : Define ancient DNA, mitochondrial DNA, and the polymerase chain reaction. LEARNING OBJECTIVE SUMMARY GENETICS 3 .1 : Recognize how genetics can be studied at different biological levels and describe each of those levels. • There are several kinds of genetic study: cellular and molecular genetics, classical or Mendelian genetics, population genetics, phylogenetics, and behavioral genetics. THE CELL 3 .2 : Understand how the cell is the basic unit of life on earth, and be able to label the components of a generic cell. • The cell is the basic building block of all life — prokaryotes versus eukaryotes. • All complex life forms are eukaryotes. • Within the body, somatic cells are the cells of the body that are not gametes (sex cells). • Stem cells are totipotent cells that can develop into different cell types. Cell Anatomy • Although cells vary tremendously according to function, they have a basic shared anatomy. • The nucleus sits within cytoplasm and houses the genetic material, deoxyribonucleic acid (DNA). • Another nucleic acid, ribonucleic acid (RNA), is also essential for cell function. • The organelles of the cell work to maintain the cell and are analogous to the organs of the body. DNA STRUCTURE AND FUNCTION 3 .3 : Compare and contrast: DNA/RNA, translation/transcription, base/codon, genes/chromosomes, and mitosis/meiosis. DNA Structure I: The Molecular Level • The basic unit of DNA and RNA is the nucleotide, which consists of a phosphate, base, and sugar. • There are four bases in DNA, and bonds formed between guanine - cytosine and adenine - thymine give the molecule its distinctive double - stranded structure. • RNA is single - stranded and has the same bases as DNA, except thymine is replaced by uracil (which also binds to adenine). DNA Function I: Replication • A major function of DNA is to make copies of itself, which allows hereditary information to be carried from generation to generation.

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    . 12 • The mechanism of DNA replication was determined by Watson and Crick at the time of their discovery of DNA structure. • The double - helix structure of DNA provides a template for the synthesis of identical copies of the molecule. DNA Function II: Protein Synthesis • Genes are defined by the sequence of bases in a stretch of DNA — they carry the information necessary to synthesize proteins. • Proteins are essential molecules in the body that perform a wide range of functions. • The genetic code converts the information of the sequence of bases in a gene into the sequence of amino acids in a protein. • There are two steps in protein synthesis: Transcription occurs in the cytoplasm and involves the synthesis of a strand of messenger RNA (mRNA); translation occurs in the cytoplasm, where the mRNA message is read at ribosomes and a protein is assembled. DNA Structure II: Chromosomes and Cell Division • The DNA in the nucleus is packaged into (relatively) large structures called chromosomes. • In somatic cells, there are two copies of each of the 22 homologous chromosomes, plus the sex chromosomes (females are XX, and males are XY); in gametes, there is only one copy of each chromosome. • Mitosis is the process of normal somatic cell division, in which the diploid chromosome number is maintained in each daughter cell. • Meiosis is the process of cell division; in sex cells are created with only one copy of each chromosome (haploid). • During meiosis, crossing over leads to novel rearrangements of genetic material. • Nondisjunction errors during meiosis can lead to a variety of chromosomal abnormalities that cause clinical problems (such as Down syndrome). MOLECULAR TOOLS FOR BIOANTHROPOLOGICAL RESEARCH 3 .4 : Define ancient DNA, mitochondrial DNA, and the polymerase chain reaction. Indirect and Direct Research Methods • In the past, researchers used various methods to measure variability at the molecular level, but today new technologies make it possible to study DNA sequence differences at the individual or species level. • The entire genomes of many species are being sequenced, following the advent of the Human Genome Project. PCR, Mitochondrial DNA, and Ancient DNA • The polymerase chain reaction (PCR) is a method for the amplification of minute quantities of DNA. • PCR makes possible the recovery of ancient DNA from bone or fossil material, up to about 100,000 years old, provided that preservation conditions were adequate. LECTURE OUTLINE I. Introduction A. Collecting organic material B. Field work followed by lab analysis C. Most striking example of power of modern genetics: ancient DNA D. Ideas about heredity found in all human cultures E. Need to understand genetics to understand how evolution happens II. The Study of Genetics A. Cellular and molecular genetics: genetics at the level of the basic building blocks of the body (cells) 1. Used to devise genetic therapies and determine precise makeup of DNA B. Classical or Mendelian genetics: looks at the pedigree of related individuals 1. Examines how traits are passed down 2. Traits must be identified as genetic features C. Population genetics: examines genetic variation within or between populations to gain insight into evolutionary history

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    . 13 D. Phylogenetics: determining evolutionary relationships using tree - like diagrams, to analyze how closely or distantly species are related E. Behavioral genetics: examines how the behavior of organisms is influenced by genetics III. The Cell A. The basic building block of life 1. One - cell versus many - celled, complex organisms 2. Basic division is between prokaryotes and eukaryotes a. Prokaryotes: single - cells with no compartments within the cell to separate genetic material b. Eukaryotes: Genetic material is separated in the nucleus surrounded by the cytoplasm that contains organelles B. Complex organisms have a variety of different somatic cell types 1. Somatic cells are simply cells that are not gametes, or sex cells 2. Adult stem cells can differentiate into a more limited variety of cell types C. Stem cell research is important and controversial in recent years 1. Embryonic stem cells and Parkinson ’ s disease 2. Stem cells found in adults can also be used for research D. Cell Anatomy 1. Almost all cells have some fundamental characteristics a. The most prominent eukaryotic feature in the cytoplasm is the nucleus b. Nucleus houses DNA, which primarily makes proteins c. RNA is also found in nucleus and is important for protein synthesis d. Mitochondria floats in the cytoplasm and produces the energy - rich molecule, ATP e. Mitochondrial DNA has been vital to evolutionary and anthropological research f. The endoplasmic reticulum aids the synthesis of proteins and ribosomes IV. DNA Structure and Function A. DNA Structure I: The Molecular Level 1. The double - helix structure of DNA a. Assembled from four different nucleotide units or bases b. Erwin Chargaff ’ s discovery : coordinating distribution patterns of bases 2. RNA follows similar structure , but single - stranded a. Ribose replaces deoxyribose as the sugar b. Uracil replaces thymine B. DNA Function I: Replication 1. Structure of DNA suites its replication a. Two strands can easily separate and be copied 2. Each stage of DNA replication is managed by an enzyme a. An enzyme is a complex protein which mediates a chemical reaction C. DNA Function II: Protein Synthesis 1. Enzymes lower the activation level of biochemical reactions 2. Proteins are composed of twenty unique amino acids a. The scope of polypeptides b. Function of proteins is determined by their amino acid sequences c. It is mathematically necessary for codons (set of three bases) to code for an amino acid 3. The part of the DNA molecule that codes for a protein is called a gene a. Can consist of hundreds of thousands of bases 4. DNA becomes proteins via transcription and translation 5. Transcription occurs when pertinent region of DNA molecule splits a. mRNA forms as a complementary set of bases to the DNA gene b. t RNA carries a single, specific amino acid to attach to the growing protein chain i. tRNA ’ s anti - codons

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    . 14 c. Most DNA codes for exons D. DNA Structure II: Chromosomes and Cell Division 1. Though mitosis and meiosis, chrom a tin condenses and replicates 2. Each somatic cell has the same number of chromosomes (diploid number) 3. Specific genes can be mapped to specific chromosomes a. E .g. , ABO blood type system 4. Mitosis: the process whereby a somatic cell replicates a. P roduces two identical daughter cells b. The cell cycle ’ s stages i. I nterphase: stage of life not involved in mitosis ii. P rophase: nuclear envelope disappears and chromosomes form iii. M etaphase: chromosomes migrate to center of cell iv. A naphase: chromatids split apart to opposite ends of cell v. T elophase: cytoplasm splits, resulting in two separate daughter cells 5. Meiosis: the formation of two gametes a. Occurs only in the testes of males and the ovaries of females b. Differences from mitosis: i. Formation of tetrads ii. Crossing over and recombination iii. Second meiotic cell division 6. Different kinds and numbers of chromosomes a. Karyotype: an image of an individual ’ s chromosomes b. Autosomes and sex chromosomes c. Even closely related species can have different numbers of chromosomes (e.g. chimpanzees) 7. Chromosomal abnormalities a. Nondisjunction errors occur during meiosis i. E .g. monosomy (Turner syndrome) or trisomy (Down syndrome) b. For the most part, monosomy or trisomy is compatible with life V. Molecular Tools for Bioanthropological Research A. Indirect versus direct research methods B. Indirect: look at the physiology and anatomy of an organism 1. However, molecular structures provide a more straightforward approach 2. Most commonly used indirect method is protein electrophoresis C. DNA sequencing: the actual base sequence of a gene 1. Most widely used tool in molecular anthropology 2. “ Molecular revolution ” of the end of the twentieth century 3. Sequencing of the entire human genome 4. Scientific payoff of sequencing is enormous D. PCR, mitochondrial DNA, and ancient DNA 1. PCR is used to make millions or even billions of copies of a specific DNA segment a. Uses fluctuating temperatures to ca tch enzyme reactions b. Taq polymerase e nzyme flag the segment of interest c. Allows the recovery of DNA from miniscule samples 2. Mitochondrial DNA resides in the mitochondria a. mtDNA regions that do not code for anything tend to evolve quickly b. Passed down c l onally from generation to generation c. All mitochondrial DNA comes from the mother 3. Ancient DNA a. PCR essential for recovering ancient DNA fragments b. Easier to amplify mtDNA than nuclear DNA c. Recent advances make it possible to recover nuclear DNA sequences as well d. Contamination is a major worry

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    . 15 LECTURE AND DISCUSSION TOPICS Each of these topics is intended to generate ideas either for lectures or for discussion in the classroom. For most topics, students should be able to respond and participate in discussions based solely on reading the text. For others, students may need further reading or other forms of information to develop some personal perspective and become equipped to make independent decisions about the topics. 1. Review different types of genetic study, including population genetics, phylogenetics, and behavioral genetics, further explaining how they are specialized and how they have advanced the overall study of genetics. 2. Refer to the Insights and Advances Box: Cloning Controversies. Review the methodology of cloning, the advantages of cloning in agriculture , and some of the drawbacks to animal cloning. Perhaps also consider the reasoning for and against human cloning. 3. Introduce the concept of PCR (polymerase chain reaction) and direct sequencing and their uses in modern forensic sciences. It would be interesting to share several murder cases with students that were solved with these techniques or to show how these techniques have cleared many convicted felons of their supposed crimes. 4. Discuss the statement made by Roger Williams that “ everyone deviated from the norm in some way. ” Even though this statement was made in the 1950s, it is interesting that further developments in DNA studies support this reasoning. 5. Add a lecture about stem cell research and the controversy surrounding it. Discuss why this might be the case and outline the various arguments for and against this area of research. 6. Discuss ancient DNA and the implications such research has had on archaeological and anthropological research. CLASSROOM ACTIVITIES 1. Arrange for students to visit a campus biotechnology program or a course in microbiology (if either is available) to see how an electrophoresis gel is created and how it is run to create DNA sequences. 2. Invite a biologist into class to lecture about a biological understanding of evolution. Check a campus library or rental catalogs for films on evolution and natural selection, DNA, molecular genetics, forensics, and DNA fingerprinting. Such films can often provide visual explanations that are clearer and more complete than simple lecture or text information. 3. Invite a historian to class to discuss the hist ory of science, with emphasis on the discussion of the scientific revolution brou ght about by Darwin and Mendel. Historical perspectives on the development of scientific fields can offer students new insights they might not otherwise gain. 4. Have students describe any genetic anomalies they know of or have been told of in their families -- extra organs, eyes that are different colors, etc., and have them describe them from the perspective of genetics as it has been discussed in the text and course. 5. Arrange a trip to a biology lab to have students view stained slides of eukaryotic and prokaryotic cells. Have them identify and draw the individual structures of the cell.

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    . 16 6. Invite a forensic scientist from a government or private lab to speak about modern techniques such as PCR or DNA fingerprinting. 7. Have students assume the role of competing theorists for the structure of DNA, double helix versus others, and examine who thought what and why. 8. Divide students into mitosis and meiosis teams and have each team describe the steps of the other process. RESEARCH AND WRITING TOPICS 1. Have the students research the various possible uses of cloning in both plants and animals. This could lead to a vibrant discussion or a term paper assignment. 2. Have students complete written or oral biographical reports on one of the following people and how their scientific ideas contributed to our modern understanding of biology: James Watson, Francis Crick, Rosalind Franklin, and Linus Pauling. 3. Have the students research how popular views about DNA (from movies or TV) has actually affected court room juries and verdicts. 4. Divide the class into two. Have each team research human cloning and then have half of the students argue in favor of reproductive human cloning while the other half argues against it. 5 . Have the students research stem cell research and have them take a stance on the issue (pro or con). They should construct their position based on the genetic benefits they have examined in class. 6. Have the students research Rosalind Franklin and discuss her contributions to the development of DNA theory. 7. Research examples of archaeological or physical anthropological research that has made use of advances in ancient DNA research. 8. Have students draw (in color) cell structures while labeling all of the organelles. Ask them to write out a description of the function of each organelle. 9. Ask students to prepare a short essay on the similarities and differences between sex cells, somatic cells, and stem cells. REVEL RESOURCES AND ACTIVITIES Activity: Review: A Typical Eukaryotic Cell Reading: Evolution Encoded Activity: The Nucleotyde Structure of DNA Reading: Regulating Evolution Activity: Review: Schematic Representation of Protein Structure

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    . 17 Activity: Review: Mitosis and Meiosis Reading: Did Life Begin in Ice?

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    . 18 CHAPTER FOUR GENETICS: FROM GENOTYPE TO PHENOTYPE LEARNING OBJECTIVES After reading and carefully considering Chapter Four , students should be able to:  4.1: Explain the genetic connection between phenotype and genotype discovered by Gregor Mendel in the nineteenth century.  4.2: Apply Mendelian genetics to modern concepts of inheritance and show how genes contribute to the expression of specific phenotypes.  4.3: Review the various types of possible mutations and discuss both their possible benefits and negative consequences.  4.4: Describe new discoveries in genetics and how polygenic traits interact with the environment to produce complex phenotypes.  4.5: Discuss phenylketonuria (PKU) as an example of both Mendelian genetics and post - Mendelian genetics. LEARNING OBJECTIVE SUMMARY FROM GENOTYPE TO PHENOTYPE 4.1 Explain the genetic connection between ph enotype and genotype discovered by Gregor Mendel in the nineteenth century. • The phenotype of an organism is the product of it s genotype and, to a greater or lesser extent, the environment in which it developed and grew. • Differences in both regulatory and structural gene s contribute to the development of unique species characteristics. MENDELIAN GENETICS 4.2 Apply Mendelian genetics to modern conce pts of inheritance and show how genes contribute to the expression of specific phenotypes. • Between 1856 and 1868, Gregor Mendel c onducted groundbreaking genetic research on the common garden pea. • Mendel ’ s laws of segregation and independent assortmen t help describe the particulate nature of inheritance. MUTATION 4.3 Review the various types of possible m utations and discuss both their possible benefits and negative consequences. • There are several kinds of mutations, including point mutations, deletion mutations, and insertion mutations. • Mutations can be detrimental to the fitness of an o rganism or they can enhance it, but many mutations are neutral because they do not lead to a change in pro tein structure or function. • Many clinical diseases are classified as Mendelian, meaning that their transmission follows a classical Mendelian pattern. GENETICS BEYOND MENDEL 4.4 Describe new discoveries in genetics and how polygenic traits interact with the environment to produce complex phenotypes. Polygenic Traits, the Phenotype, and the Environment • Most biological traits we are interested in cannot be studied using simple Mendelian genetics.

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    . 19 • Many traits are polygenic — the combined result of more than one gene, each of which may have more than one allele. • Many genes are pleiotropic — they have multiple eff ects, on their own and in their interaction with other genes. • Continuous quantitative variation (for example, as seen in a normal curve distribution) for a trait is typically seen for polygenic traits. Heritability and IQ Test Score Performance • Heritability is a statistic geneticists use to quantify the proportion of all variation observed for a trait that can be attributed to ge netic rather than environmental factors. • For complex phenotypes such as IQ, it is crit ical to keep in mind that while heritability may indicate a genetic component in its distribution, the heritability value itself may vary among populations according to environmental conditions. PHENYLKETONURIA: ILLUSTRAT ING MENDELIAN AND POST - MENDELIAN CONCEPTS 4.5 Discuss phenylketonuria (PKU) as an example of both Mendelian genetics and post - Mendelian genetics. • PKU is a disease whose genetics, diagnosis, and treatment serve to illustrate a host of concepts relating to the complex interaction between genotype and phenotype. LECTURE OUTLINE I. Introduction A. Mendel and Bateson 1. Painstaking breeding experiments 2. Bateson read decades after publication B. Human genetics encompass a wide range of phenomena 1. Genetics vitally important to understand evolution 2. Key role in many contemporary medical and cultural issues II. From Genotype to Phenotype A. Connection between genes and the physical traits we can observe 1. Structural genes contain information and make proteins 2. Regulatory genes guide the expression of structural genes a. Initiate, promote, or terminate transcription B. Genetic relations between species 1. Structural genes may be quite similar across related species 2. Regulatory genes critical in determining the form of an organism a. e.g., Chimpanzee and human 95 % – 96% identical; species differentiation due to regulatory genes ’ insertions, deletions, etc . 3. Wilhelm Johannsen introduced the terms genotype and phenotype a. Genotype is the set of specific genes an organism carries b. Phenotype is the observable physical feature of an organism under some genetic control or influence C. The ABO blood type system 1. Straightforward relationship between genotype and phenotype in the ABO system 2. Gene has three alleles: A, B, and O a. A and B stand for versions of the protein modified by enzymes from a common precursor b. O has only the precursor version of the protein c. We have two copies of each gene on each chromosome 3. An allele that must be present on both chromosomes to be expressed is recessive 4. An allele that must be present only once is dominant 5. ABO allows for six genotypes and four phenotypes a. The phenotype is a direct product of the genotype b. Not subject to environmental intervention

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    . 20 D. Obesity: A Complex Interaction 1. Obesity is a more complex example of the interaction between genes, environment, and phenotypes 2. Research indicates that there are specific genes that are critical to regulating appetite a. Some individuals have alleles for these genes that make it difficult to regulate i. These individuals tend to become morbidly obese ii. Despite progress, molecular studies have yet to uncover genetic causes of obesity iii. Genetic causes likely exist, based on pedigree studies of related individuals 3. Obesity also depends on the amount of food in the environment a. Even if someone is predisposed, they will not become obese if there isn ’ t enough food b. “ Epidemic of Obesity ” c. Obesity phenotype is the product of genes and environment i. True even for people without an “ obesity gene ” III. Mendelian Genetics A. Gregor Mendel ’ s careful experimental demonstrated particulate inheritance 1. Conducted experiments between 1856 and 1868 2. Ideal sample because peas showed dichotomous variation 3. Monitored different varieties of common garden peas a. Included a series of hybridizations b. Mendel carefully recorded transmission of characteristics i. seed coat ii. seed color iii. pod shape iv. pod color v. flower color vi. stem form vii. stem size 4. Observed similar results for each feature he examined a. Even true - breeding crosses only showed one parental trait expressed b. Traits that had disappeared in earlier generations reappeared in ¼ of offspring B. Mendel ’ s Postulates 1. Hereditary characteristics are controlled by particulate unit factors a. Factors exist in pairs in individual organisms b. Different versions of a unit factor may exist c. An individual may have two factors that are the same or two that are different 2. When an individual has two different unit factors responsible for a characteristic, only one is expressed a. The expressed factor is said to be dominant to the other b. The other is said to be recessive 3. During the formation of gametes, the paired unit factors separate, or segregate, randomly a. Each sex cell receives one or the other with equal likelihood b. Punnett square illustrates parental contributions to offspring 4. During gamete formation, segregating pairs of unit factors assort independently of one another a. Called Mendel ’ s law of independent assortment b. Mendel carried out more complicated dihybrid crosses c. Found no correlation between simultaneously transmitted traits C. Linkage and crossing over 1. Law of independent assortment only applies to genes that are on different chromosomes 2. Because chromosome is the unit of transmission in meiosis, linkage occurs a. Genes located on the same chromosome will travel together 3. Independent assortment of linked genes is relatively common

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    . 21 a. Occurs during crossing over, or recombination b. Likelihood of crossing over is a function of distance between genes c. Genes located near one another are more strongly linked IV. Mutation A. Mutation is essentially an error that occurs in DNA replication 1. Any change that becomes established in the daughter cell 2. Changes that occur in structural or regulatory genes more critical than those in noncoding sections B. Point mutation and sick cell disease 1. A point mutation occurs when a single base in a gene is changed 2. One of the most well - known examples is sick cell disease a. Caused by an abnormal form of hemoglobin b. Hemoglobin is normally very malleable and cohesive i. Sickled cells lose flexibility and impair circulation ii. Also damages red blood cells themselves iii. Causes and exacerbates anemia c. Management of sickle cell includes hydroxyurea therapy i. Promotes the production of fetal hemoglobin d. Sickle cell hemoglobin (HbS) is only one amino acid different from healthy adult hemoglobin (HbA) e. Not directly fatal because the mutation does not render cells totally incapable of carrying oxygen f. Sickle cells appears in homozygous HbS carriers i. Latent heterozygous carriers C. Insertion and Deletion Mutations 1. Results from insertion or deletions in the genetic code a. In recent years, such mutations have been linked to many congenital diseases b. At least seventeen diseases linked to one insertion of triple - base sequences 2. Huntington disease a. Degenerative autosomal dominant disease b. Increased repetitions of CAG sequence on chromosome four c. Depending on number of repetitions, onset could occur earlier or later in life 3. Williams syndrome a. Results from deletion of twenty - eight genes from chromosome seven b. Observable “ elfin ” appearance c. Prone to cardiac issues and decreased size of brain regions d. Generally , retain strong language, music skills, and social adeptness i. May help advance understanding of genetic basis for social behavior D. Mutations: Bad, Neutral, and Good 1. Idea of bad mutations pervades popular culture 2. Mutations that occur in noncoding sections have no impact on phenotype and are neutral 3. Mutations are neutral if they do not change the amino acid a. Some proteins can endure amino acid substitutions b. No observable functional consequences 4. Mutations may affect anatomy without affecting fitness, e.g. , Habs b urg jaw 5. Mutations as good a. Ultimate source of genetic variation, the raw material of evolution b. Positive mutations do not have to be plentiful; they proliferate in populations i. Become the normal or wild type 6. Many autosomal dominant disorders occur with very small probability E. X - linked disorders 1. Directly related to chromosome structure 2. Human males only have one X chromosome a. They are therefore more susceptible X - linked disorders b. Pedigrees show a typical pattern whereby disorders appear to skip a generation c. Sons will display the disorder if they receive a carrying X chromosome

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    . 22 3. Fatal X - linked disorders before reproductive age are never seen in females 4. Hemophilia is perhaps the most well - known X - linked disorder a. Absence of one of the clotting proteins in blood b. With advancing treatment, males with this disorder are able to live long, productive lives 5. Red color blindness and green color blindness are X - linked disorders a. Frequency much lower in women than in men F. Mendelian Genetics in Humans 1. Hundreds of human disorders can be explained in Mendelian terms 2. Online Mendelian Inheritance in Man (OMIM) V. Genetics Beyond Mendel A. Mendelian genetics provides a foundation for understanding 1. Most useful for understanding traits for which there is qualitative variation (e.g. , albinism) 2. Quantitative variation indicates continuous variation for some trait (e.g. , stature in humans) B. Complex, polygenic traits like skin color, timing of puberty, and stature 1. Depend on the actions of multiple genes 2. Single genes that produce qualitative variants do not cause the whole trait 3. One gene with multiple phenotypic effects is called pleiotropy C. Polygenic Traits, the Phenotype, and the Environment 1. Expression of many traits result from interaction of genes and environment a. Heritability can r ange from 0 to 1 b. Several strategies to estimate heritability in populations (e.g. , adoption studies) 2. Heritability does not provide information about how many genes are responsible for the trait a. Does not provide an absolute measure of the genetic contribution to a phenotype b. Environment variability D. IQ test score performance perhaps best known and most controversial heritability study 1. Cannot use heritability to pinpoint ethnic differences on genetics 2. Variation between groups results from genetics, the environment, or both VI. Phenylketonuria: Illustrating Mendelian and Post - Mendelian Concepts A. Before neonatal screening, PKU was among the most common causes of mental retardation 1. Appears to follow classic Mendelian rules 2. Caused by a recessive allele B. PKU sufferers accumulate up to forty - times normal levels of phenylalanine 1. The result of a deficiency of an enzyme 2. Over the past thirty years, location and behavior of PKU mapped C. Screening for PKU in newborns assesses phenylalanine levels 1. Dietary treatments and challenges 2. Gene therapy a possibility in the future D. A striking example of relationships between genotype, phenotype, and the environment E. Genes and Environments 1. Genetic environment just as important to phenotype development as any other environment 2. Mendelian concepts useful in establishing genes ’ isolation from one another 3. Twenty - first century genetics will determine how genes work together in complex environments LECTURE AND DISCUSSION TOPICS Each of these topics is intended to generate ideas either for lectures or for discussion in the classroom. For most topics, students should be able to respond and participate in discussions based solely on reading the text. For others, students may need further reading or other forms of information to develop some personal perspective and become equipped to make independent decisions about the topics.

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    . 23 1. Supporters of Eugenics were very passionate in their beliefs. This may be a good place to discuss the power of new ideas developed by science and how easily people take them out of context. You can probably find even more modern examples to use as a comparison. 2. X - linked diseases and disorders are always fascinating. They are directly related to chromosome structure. As human males are heterogametic they are prone to disorders due to X chromosome mutations. A discussion of several X - linked disorders would be interesting and could include Lesch - Nyhan syndrome, hemophilia, red - color blindness, green - color blindness, etc. By going to the Online Mendelian Inheritance in Man database at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=Search&DB=omim you can find descriptions of over 1,000 X - linked disorders. 3. Develop the concept of polygenesis and link this to an explanation why phenotype is not so easily predicted. 4. Discuss IQ tests and whether they provide any useful information or whether they have only been used in a discriminatory manner. 5 . Discuss how mutations can be both deleterious and necessary for evolution to occur. 6. Discuss obesity in the world and note how an individual ’ s genetics and environment in which they live can be factors in its development . 7 . Discuss the following quotation with your students: “ There is no progress in evolution. The fact of evolutionary change through time doesn ’ t represent progress as we know it. Progress isn ’ t inevitable. Much of evolution is downward in terms of morphological complexity, rather than upward. We ’ re not marching toward some greater thing. ” Stephen Jay Gould: The Pattern of Life ’ s History from The Third Culture (Simon & Schuster, 1995) CLASSROOM ACTIVITIES 1. Have students bring in lists of products that contain the artificial aspartame. Show how this sweetener can be dangerous to those who suffer from PKU but not to those who don ’ t. 2. Either ask students to provide their blood types or test them in class with the proper antigen kits. See how the distribution of ABO blood types compares to the population norm. 3. Ask students to identify human polygenic traits; explain what they are and the variation inside of the trait. 4. Determine if any students have or c an recognize a phenotypic trait that is distinguishable from a genotypic trait. Do any possess traits that they can ascribe to an activity or behavior? 5. Ask students if any of the mutations discussed in class occur in their family histories. Discuss their frequency. 6 . Examine Mendel ’ s experiment by assigning students a specific trait and then having them arrange themselves based on Mendel ’ s different laws. RESEARCH AND WRITING TOPICS 1. Students should be asked to research point mutations and write a paper on their effects. Many resources exist on the following website: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/M/Mutations.html .

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    . 24 2. Have students write a paper on how complex human stature is as a polygenic or continuous trait. The following website may be of use in starting the research project: http://anthro.palomar.edu/mendel/mendel_3.htm . 3. Herrstein ’ s and Murray ’ s book The Bell Curve sparked an immediate controversy when it delved into IQ and racial classification. Have students review the following statements by 52 prominent researchers of intelligence. It can be found at: http://www.cpsimoes.net/artigos/bell_mainstr.html . 4. Divide your class into groups that can research Mendel ’ s various postulates. Each group should give a report on his classic discoveries. 5. Have students research historical figures known to have had mutations as discussed in class. Students should determine in what way, if any, these mutations affected their lives. 6. Have students research obesity, examining it from both its genetic and environmental factors. Which contributes more to the obesity of an individual? Genetics or the environment? 7. Have students research Gregor Mendel. How did a monk develop and explore such a scientific curiosity ? Did his research lead to any conflict in his life? 8 . Have a student review the following medical article that summarizes new information on trinucleotide repeat diseases. How many diseases are there? Of what type are they? How new is the information on TRD? See: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=1 0767314&itool=iconfft . 9 . Ask students to prepare a short essay on phenylketonuria (PKU). What are the results of this condition? What are the causes? What environmental factors must be screened? What products contain phenylalanine? How does PKU demonstrate an interrelationship between genotype, phenotype, and the environment? For more information see the following website: http://www.ncbi.nlm.nih.gov/disease/Phenylketo.html . REVEL RESOURCES AND ACTIVITIES Reading: Evolutionary Genetics Activity: Explore: The Traits Mendel Used in His Experiments Activity: Explore: The Punnett Square Activity: Contrasting Polygenic and Pleiotropic Effects

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    25 . CHAPTER FIVE THE FORCES OF EVOLUTION AND THE FORMATION OF SPECIES LEARNING OBJECTIVES After reading and carefully considering Chapter F ive , students should be able to:  5.1 Describe the process of how evolution works, by explaining the five forces of evolution: mutation, natural selection, gene flow, genetic drift, and nonrandom mating.  5.2 Understand the science of classification of plants and animals: taxonomy.  5.3 Describe what a species is and how species are formed.  5.4 Understand the concept of biological adaptation and how adaptive traits evolve.  5.5 Contrast individual selection against group selection; explain kin selection and inclusive fitness. LEARNING OBJECTIVE SUMMARY HOW EVOLUTION WORKS 5.1 Describe the process of how evolution works, by explaining the five forces of evolution: mutation, natural selection, gene flow, genetic drift, and nonrandom mating. • There are five primary forces of the evolutionary process: • Mutation is the only source of new variation. • Natural selection is the filter that acts on variation. • Gene flow is the biological name for migration. • Genetic drift is evolution by random chance. • Nonrandom mating is about mate selection and what drives it. • Sexual selection is differential reproductive success within one sex. CLASSIFICATION AND EVOLUTION 5.2 Understand the science of classification of plants and animals: taxonomy. • Taxonomy is the science of classification, begun in the eighteenth century by Carl von Linnaeus. WHAT IS A SPECIES? 5.3 Describe what a species is and how species are formed. • There is no single species concept: Different definitions can be applied depending on the context. • Species are formed in a variety of ways. Two of these are allopatric speciation and parapatric speciation. • Speciation can happen at widely varying speeds. ADAPTATION 5.4 Understand the concept of biological adaptation and how adaptive traits evolve. • Scientists argue about whether every single trait in an organism is adaptive. • Hardy – Weinberg explains how a population without evolutionary change would look. LEVELS OF SELECTION 5.5 Contrast individual selection against group s election; explain kin selection and inclusive fitness. • There are proximate and ultimate explanations for evolutionary change. • Animals base their behavior toward other animals on potential genetic benefits.

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    26 . LECTURE OUTLINE I. Introduction A. Observing gradual change in Galapagos beak size 1. Now - famous study by Peter and Rosemary Grant B. Difficulty of demonstrating natural selection in the wild 1. Takes many generations to be apparent II. How Evolution Works A. Evolution is driven by factors occurring in natural populations that cause changes in gene frequencies 1. Natural selection is the most widely cited cause of evolution 2. Several other causes exist as well B. Where does variation come from? 1. Variations in DNA during replication 2. Point mutation is a change in a DNA molecule base 3. Larger - scale errors result in chromosomal mutations 4. Mutations of great significance occur rarely a. Only through the accumulation of mutations do new traits enter populations b. Evolutionary forces filter out undesirable traits C. How natural selection works 1. Takes the package of traits from the previous generation and alters it in response to environment a. Environment is the filter through which traits are selected for or removed b. Natural selection operates on the phenotype of an individual i. Cultural practices ( e.g., sunbathing) can have evolutionary effects 2. Populations evolve as the frequency of genes change a. Change occurs very slowly b. Easier to study in animals with short generations c. Artificial selection analogous to natural selection 3. Directional selection occurs in response to selection pressures a. e.g., Finches ’ beak sizes and food scarcity 4. Stabilizing selection helps to keep populations uniform a. e.g., Sparrows either killed or survived snowstorm 5. Showing natural selection at work in human population is very difficult a. One easier example is birth weight b. Natural selection favors a healthy range of birth weights D. Other ways by which evolution happens 1. Power of natural selection still a topic of debate a. Critics argue that natural selection alone cannot account for rapid evolution 2. Gene flow: movement of genes between populations a. Extended periods of gene flow can create one larger gene pool b. Changes in social behavior can also end gene flow c. Gene flow can eliminate some harmful effects of inbreeding 3. Genetic drift: random changes in gene frequency in a population a. Caused entirely by random factors b. Important mainly in small populations c. Founder effect: a small subset of a larger population becomes isolated i. Only contains genotypes of the “ founders ” ii. e.g., Pitcairn Islanders d. Closed societies also demonstrate genetic drift ( e.g., the Amish and EVC) e. Genetic bottleneck is associated with genetic drift i. A large diverse population undergoes a rapid reduction in size ii. Remaining organisms define the genotype ( e.g., lacking disease resistance)

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    27 . 4. Sexual selection described by Darwin in The Descent of Man a. Social animals select for their mates b. Leads to sexual dimorphism i. Females then use males ’ features to define direct or indirect benefits c. R.A. Fisher ’ s idea of runaway sexual selection i. Elaborate features mean costly signaling ii. Handicap principle displays ability to survive 5. Reproductive potential leads to competition for females a. Females have more limited reproductive potential than males b. Males and females also differ in their reproductive variance 6. Testing causes of male ornamentation a. Role reversal in certain species III. Classification and Evolution A. Taxonomy and speciation 1. Linnaeus classified animals based on physical characteristics ( e.g., sorting wines) a. However, animals are dynamic units b. Changes may be too small or gradual to observe c. Treating animals as separate categories does not reflect biological realities 2. Linnaeus established a hierarchy of categories for all living things a. As one descends in each category, distinctions become smaller b. Only “ natural ” distinction is the species 3. Today ’ s classification system is all systematics a. Relies on principle of homology b. Links species by shared evolutionary features c. Bat and bird wings represent analogous features i. Such features arise through convergent evolution ii. One puzzle is that similar adaptations emerge in similar environments 4. We use anatomical characters (i.e. physical features) to categorize organisms . A new brand of classification is call cladistics a. In this system, some traits are considered more evolutionarily important than others b. Ancestral versus derived traits c. Cladogram is a branching diagram showing evolved relationships among members of a lineage d. A clade is a cluster of species linked by a set of unique traits e. One worry: what if a trait evolved twice? 5. Phenetics, or numerical taxonomy, is another approach to systema tics a. Relies solely on describing degrees of similarity and difference numerically b. Considers all traits c. Now out of fashion IV. What Is a Species? A. Species are dynamic, ever - changing entities B. Not an easy question to answer 1. In Linnaeus ’ s time, considered pigeon - holed, definite entities 2. Difficult to define because of the amount of variation found in nature C. Previous generations had to be guided by outward appearance 1. Today we have DNA analysis, studies of physiology, ecology, and behavior 2. The problem of defining what a species is remains D. A guide to species concepts 1. Most widely used definition is the biological species concept a. First proposed by Ernst Mayr b. Defines species as interbreeding populations reproductively isolated c. Question of defining “ actually or potentially ” reproductively separated d. Definition referred to natural populations only e. e.g., Ligers 2. No less than twenty - five other species definitions have been proposed

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    28 . a. Evolutionary species concept: evolutionary lineages with unique identities b. Ecological species concept:: Defines species based on the uniqueness of their ecological niche c. Recognition species concept: based on unique traits or behaviors that allow members of one species to identify them for mating E. Reproductive isolating mechanisms 1. Any factor that prevents male and female of two different species from hybridizing 2. May be premating or postmating mechanism F. The origin of species: how species are formed 1. Anagenesis a. In this mode of change, one species gradually becomes another b. The first species ceases to exist or be identifiable 2. Cladogenesis a. A species may branch into two or more new species b. The first species may not continue to exist 3. One specific process by which new species form is allopatric speciation a. Geographic separation triggers emergence of new species b. e.g., A river forms and separates initially connected populations c. If two new species meet again, reinforcement occurs i. Any hybridization would be less fit 4. A second mechanism is parapatric speciation a. Occurs when two populations have continuous distributions, and parts of the population diverse more than others b. Often a zone overlap remains c. Divergences can include mating behavior d. Allows primatologists to understand the genetic influence over certain traits 5. A third mode is sympatric speciation a. Occurs when ecological factors create more than one phenotype in a population b. No spatial separation necessary c. Relatively few examples of sympatric speciation d. Can occur due to large - scale chromosomal mutation 6. The tempo of speciation a. Gradualism is widely accepted as the most prevalent type of evolution i. Plants and animals evolve slowly over vast periods of time b. Macroevolution is large - scale evolutionary change occurring over a long time c. The fossil record is incomplete and fragmentary i. If more complete, it would show these gradual changes ii. An alternative explanation for fossil record gaps is macroevolution d. Macroevolution is rapid, large - scale evolutionary cha nges e. Punctuated equilibrium holds that most species ’ phenotypes remain static i. Species change very little over long periods ii. These long periods are then punctuated by bursts of evolutionary change f. Punctuated equilibrium is a severe departure from Darwinism i. Most scientists are skeptical of punctuated equilibrium ii. The fossil record is fragmentary iii. There is evidence that species change slightly over time iv. A good example of how scientists ’ views differ widely V. Adaptation A. Adaptations are evolved phenotypic traits that increase an organism ’ s reproductive success 1. Concept central to modern biology 2. Some biologists consider any well - designed trait to be an adaptation 3. Others are stricter, saying the trait must still be serving its original purpose 4. Theories about why traits evolved are difficult to disprove 5. Some scientists hold with adaptationism a. All traits of an organism are products of adaptation

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