Human Heredity (with InfoTrac) Principles and Issues

by Cummings, Michael

• ISBN13: 9780534523725
• ISBN10: 0534523722
• Format: Paperback
• Copyright: 1999-08-30
• Publisher: Brooks Cole

Author Biography

Michael R. Cummings University of Illinois at Chicago

Table of Contents

Preface	xix
Genetics as a Human Endeavor	1	(13)
Welcome to Genetics	2	(1)
Concepts and Controversies Genetic Disorders in Culture and Art	3	(1)
What are Genes and How do They Work?	3	(1)
How are Genes Transmitted From Parents to Offspring?	4	(1)
How do Scientists Study Genes?	5	(3)
Approaches to the Study of Genetics	5	(2)
Basic and Applied Research	7	(1)
What is the Historical Impact of Genetics on Society?	8	(1)
Genetics and Social Policy	8	(1)
Eugenics and Immigration Laws	8	(1)
Eugenics and Reproductive Rights	8	(1)
Eugenics and the Nazi Movement	9	(1)
When did Human Genetics Get Started?	9	(1)
Concepts and Controversies Genetics, Eugenics, and Nazi Germany	10	(1)
Where is Human Genetics Going in the Future?	11	(2)
Internet Activities	13	(1)
For Further Reading	13	(1)
Cells, Chromosomes, and Cell Division	14	(32)
Two Main Types of Cells: Prokaryotic and Eukaryotic	15	(1)
Cell Structure Reflects Function	15	(7)
There is a Wide Range of Cell Sizes	16	(1)
The Plasma Membrane and the Cytoplasm Are Two Cellular Domains	17	(1)
Organelles Are Specialized Structures in the Cytoplasm	18	(4)
Guest Essay Exploring Membranes	22	(1)
Anne Walter
Chromosomes Have a Characteristic Structure	22	(2)
The Cell Cycle Describes the Life History of A Cell	24	(2)
Interphase Has Three Stages	24	(2)
Concepts and Controversies Sea Urchins, Cyclins, and Cancer	26	(5)
Cell Division by Mitosis Occurs in Four Stages	26	(5)
Mitosis is Essential for Growth and Cell Replacement	31	(1)
Cell Division by Meiosis: The Basis of Sex	32	(7)
Meiosis I Reduces the Chromosome Number	32	(2)
Meiosis II Begins with Haploid Cells	34	(1)
Meiosis Produces New Combinations of Genes in Two Ways	34	(5)
Spermatogenesis and Oogenesis are Processes That Form Gametes	39	(3)
Case Studies	42	(1)
Summary	43	(1)
Questions and Problems	43	(2)
Internet Activities	45	(1)
For Further Reading	45	(1)
Transmission of Genes from Generation to Generation	46	(28)
Heredity: How Does it Work?	48	(1)
Mendel's Experimental Approach Resolved Many Unanswered Questions	48	(2)
Crossing Pea Plants: The Principle of Segregation	50	(2)
Results and Conclusions from Mendel's First Series of Crosses	50	(2)
Concepts and Controversies Ockham's Razor	52	(3)
Inheritance of a Single Trait: The Principle of Segregation	53	(2)
More Crosses With Pea Plants: The Principle of Independent Assortment	55	(3)
Crosses Involving Two Traits	55	(1)
Methods, Results, and Conclusions	55	(1)
The Principle of Independent Assortment	56	(2)
Concepts and Controversies Evaluating Results---The Chi-Square Test	58	(2)
Meiosis Explains Mendel's Results: Genes are on Chromosomes	60	(2)
Many Genes Have More Than Two Alleles	62	(1)
Variations on a Theme by Mendel	62	(2)
Both Codominant Alleles are Expressed in the Phenotype	63	(1)
Incomplete Dominance Has a Distinctive Phenotype	63	(1)
The Concepts of Dominance and Recessiveness	64	(1)
Mendelian Inheritance in Humans	64	(2)
Pedigree Analysis in Human Genetics	65	(1)
Concepts and Controversies Solving Genetics Problems	66	(3)
Case Studies	69	(1)
Summary	70	(1)
Questions and Problems	70	(2)
Internet Activities	72	(1)
For Further Reading	73	(1)
Pedigree Analysis in Human Genetics	74	(36)
Humans as a Subject for Genetics	76	(1)
Pedigree Construction is a Basic Method in Human Genetics	76	(2)
There is a Catalog of Mendelian Genetic Disorders	78	(1)
Concepts and Controversies Was Noah an Albino?	79	(1)
Autosomal Recessive Traits	79	(6)
Cystic Fibrosis is a Recessive Trait	80	(3)
Sickle Cell Anemia Is a Recessive Trait	83	(2)
Autosomal Dominant Traits	85	(3)
The Pattern of Inheritance for Autosomal Dominant Traits	85	(1)
Marfan Syndrome Is an Autosomal Dominant Trait	85	(3)
Sex-Linked Inheritance Involves Genes on the X and Y Chromosomes	88	(7)
X-Linked Dominant Inheritance	90	(1)
X-Linked Recessive Inheritance	91	(2)
Muscular Dystrophy Is an X-Linked Recessive Trait	93	(2)
Concepts and Controversies Hemophilia and History	95	(1)
Y-Linked Inheritance Involves Transmission from Male to Male	95	(1)
Mitochondrial Inheritance is From Mother to Offspring	96	(1)
Several Factors Cause Variations in Gene Expression	97	(1)
Temperature and Gene Expression	97	(1)
Guest Essay Nothing in Biology Makes Sense without Evolution	98	(2)
Michael Rose
Age and Gene Expression	98	(1)
Penetrance and Expressivity Are Variations in Gene Expression	99	(1)
Genes on the Same Chromosome are Linked	100	(1)
Using Linkage and Recombination Frequencies to Make Genetic Maps	101	(1)
Linkage and Recombination can be Measured by a Lod Score	102	(2)
Case Studies	104	(1)
Summary	105	(1)
Questions and Problems	105	(3)
Internet Activities	108	(1)
For Further Reading	108	(2)
Polygenes and Multifactorial Inheritance	110	(30)
Some Traits are Controlled by Two or More Genes	111	(1)
Polygenes and Variations in Phenotype	112	(5)
The Additive Model for Polygenic Inheritance	115	(1)
Averaging Out the Phenotype: Regression to the Mean	116	(1)
Polygenes and the Environment: Multifactorial Traits	117	(1)
Threshold Effects and the Expression of Multifactorial Traits	117	(1)
Concepts and Controversies Is Autism a Genetic Disorder?	118	(1)
Estimating the Interaction between Genotype and Environment	119	(1)
Phenotypic Variation is Measured by Heritability	119	(2)
Heritability Estimates are Based on Genetic Relatedness	119	(1)
Using Fingerprints to Estimate Heritability	120	(1)
Twin Studies and Multifactorial Traits	121	(5)
The Biology of Twins	122	(1)
Concordance and Twins	123	(1)
Using Twins to Study Obesity	124	(1)
Genetic Clues to Obesity	125	(1)
Concepts and Controversies Twins, Quintuplets, and Armadillos	126	(1)
A Survey of Some Multifactorial Traits	127	(9)
Cardiovascular Disease Has Genetic and Environmental Components	127	(3)
Skin Color Is a Multifactorial Trait	130	(2)
Intelligence and IQ: Are They Related?	132	(2)
The Controversy about IQ and Race	134	(1)
Searching for Genes That Control Intelligence	135	(1)
Case Studies	136	(1)
Summary	137	(1)
Questions and Problems	137	(1)
Internet Activities	138	(1)
For Further Reading	138	(2)
Cytogenetics	140	(34)
The Human Chromosome Set	141	(3)
Concepts and Controversies Making a Karyotype	144	(2)
Analyzing Chromosomes and Karyotypes	146	(2)
Getting Cells for Chromosome Studies	146	(2)
Concepts and Controversies Using Fetal Cells from the Mother's Blood	148	(3)
Amniocentesis Collects Cells from the Fluid Surrounding the Fetus	148	(2)
Chorionic Villus Sampling Retrieves Fetal Tissue from the Placenta	150	(1)
Variations in Chromosomal Number	151	(6)
Polyploidy Changes the Number of Chromosomal Sets	151	(2)
Aneuploidy Changes the Number of Individual Chromosomes	153	(1)
Monosomy Is Rare	153	(1)
Trisomy is Relatively Common	154	(3)
What are the Risks for Autosomal Trisomy?	157	(1)
Maternal Age Is the Leading Risk Factor for Trisomy	157	(1)
Why Is Age a Risk Factor?	158	(1)
Aneuploidy of the Sex Chromosomes	158	(4)
Turner Syndrome (45,X)	158	(2)
Klinefelter Syndrome (47,XXY)	160	(1)
XYY Syndrome (47,XYY)	161	(1)
Aneuploidy of the Sex Chromosomes: Some Conclusions	161	(1)
Structural Alterations Within Chromosomes	162	(4)
Deletions Involve Loss of Chromosomal Material	163	(1)
Translocations Involve Exchange of Chromosomal Parts	164	(2)
What are Some Consequences of Aneuploidy?	166	(1)
Other Forms of Chromosomal Abnormalities	167	(3)
Uniparental Disomy	167	(1)
Fragile Sites	167	(3)
Case Studies	170	(1)
Summary	170	(1)
Questions and Problems	171	(1)
Internet Activities	172	(1)
For Further Reading	172	(2)
Development and Sex Determination	174	(26)
Human Development from Fertilization to Birth	175	(6)
Human Development Is Divided into Three Stages	178	(3)
Birth Occurs in Stages	181	(1)
Reproduction and Technology	181	(2)
Contraception Uncouples Sexual Intercourse from Pregnancy	181	(1)
Technology Expands Reproductive Choices	182	(1)
Teratogens Pose a Risk to the Developing Fetus	183	(2)
Little Is Known about Teratogens	184	(1)
Fetal Alcohol Syndrome	184	(1)
Sex Determination in Humans	185	(2)
Chromosomes Can Help Determine Sex	185	(2)
The Sex Ratio in Humans	187	(1)
Sex Differentiation Follows Sex Determination	187	(1)
Chromosomal Sex and Phenotypic Sex	187	(1)
Events in Embryogenesis Begin Sex Differentiation	187	(1)
Concepts and Controversies Sex Testing in International Athletics---Is It Necessary?	188	(3)
Genetic Control of Sexual Differentiation	191	(2)
Androgen Insensitivity and Phenotypic Sex	192	(1)
Gene Expression and Sexual Phenotype	192	(1)
Concepts and Controversies Joan of Arc---Was It Really John of Arc?	193	(1)
Dosage Compensation and the X Chromosome	193	(4)
Expression of Genes on the X Chromosome	193	(1)
Barr Bodies and X Inactivation	194	(1)
Females are Mosaics for X-Linked Genes	195	(1)
Sex-Influenced and Sex-Limited Traits	196	(1)
Case Studies	197	(1)
Summary	197	(1)
Questions and Problems	198	(1)
Internet Activities	199	(1)
For Further Reading	199	(1)
DNA Structure and Chromosomal Organization	200	(19)
DNA Carries Genetic Information	202	(1)
Transfer of Genetic Traits in Bacteria	202	(1)
Concepts and Controversies DNA as a Commercial Product	203	(1)
DNA Is a Part of Chromosomes	203	(1)
Watson, Crick, and the Structure of DNA	204	(7)
Reviewing Some Basic Chemistry	204	(1)
Nucleotides: The Building Blocks of Nucleic Acids	205	(1)
DNA Is a Double Helix	206	(4)
RNA Is Single-Stranded	210	(1)
DNA is Coiled With Proteins to Form Chromosomes	211	(3)
The Mitochondrial Chromosome Is a Circular DNA Molecule	211	(1)
Nuclear Chromosomes Have a Complex Structure	211	(3)
DNA Replication Depends on Base Pairing	214	(1)
Case Studies	215	(1)
Summary	216	(1)
Questions and Problems	216	(1)
Internet Activities	217	(1)
For Further Reading	218	(1)
Gene Expression: How Proteins Are Made	219	(21)
The Link Between Genes and Proteins	220	(2)
Genes and Metabolism	221	(1)
The Relationship between Genes and Enzymes	221	(1)
How is Genetic Information Stored in DNA?	222	(1)
The Flow of Genetic Information is a Multistep Process	222	(4)
Transcription Produces Genetic Messages	223	(1)
Genes Can Have a Complex Internal Organization	224	(1)
Messenger RNA Is Processed and Spliced	224	(1)
Translation Requires the Interaction of Several Components	225	(1)
Concepts and Controversies Antibiotics and Protein Synthesis	226	(4)
The Genetic Code: The Key to Life	230	(1)
The Polypeptide Product of Translation	231	(5)
Proteins Have Several Levels of Structure	232	(1)
Proteins Have Many Functions	232	(4)
Case Studies	236	(1)
Summary	236	(1)
Questions and Problems	237	(2)
Internet Activities	239	(1)
For Further Reading	239	(1)
From Proteins to Phenotypes	240	(27)
The Role of Proteins	241	(1)
Proteins are the Link Between Genotype and Phenotype	242	(1)
Metabolic Pathways and Genetic Disorders	242	(3)
Phenylketonuria: A Defect in Amino Acid Metabolism	244	(1)
Concepts and Controversies Garrod and Metabolic Disease	245	(3)
Other Metabolic Disorders in the Phenylalanine Pathway	246	(1)
Defects in Carbohydrate Metabolism	246	(2)
Concepts and Controversies Dietary Management and Metabolic Disorders	248	(2)
Mutations in Receptor Proteins: Familial Hypercholesterolemia	250	(2)
The Globin Genes: Unlocking the Protein-Phenotype Link	252	(8)
Sickle Cell Anemia	255	(1)
Other Hemoglobin Variants	256	(1)
Thalassemias	257	(2)
Treatment of Hemoglobin Disorders by Gene Switching	259	(1)
Pharmacogenetics and Ecogenetics	260	(3)
Taste and Smell Differences: We Live in Different Sensory Worlds	260	(1)
Drug Sensitivities are Genetic Traits	261	(1)
Pesticide Metabolism	262	(1)
Case Studies	263	(1)
Summary	263	(1)
Questions and Problems	264	(2)
Internet Activities	266	(1)
For Further Reading	266	(1)
Mutation: The Source of Genetic Variation	267	(23)
The Nature of Mutation	268	(1)
Detecting Mutations	269	(1)
Measuring Mutation Rates	270	(2)
Gene-Specific Mutation Rates	271	(1)
Factors That Influence the Mutation Rate	271	(1)
Enrivonmental Factors That Influence Mutation Rates	272	(3)
Radiation Is One Source of Mutations	272	(1)
How Much Radiation Are We Exposed To?	273	(1)
Action of Chemical Mutagens	274	(1)
Concepts and Controversies Irradiated Food	275	(1)
Mutation at the Molecular Level: DNA as a Target	276	(5)
Nucleotide Substitutions	276	(2)
Deletions and Insertions	278	(1)
Trinucleotide Repeats, Gene Expansion, and Mutation	279	(1)
Allelic Expansion and Anticipation	280	(1)
DNA Repair Mechanisms	281	(1)
DNA Repair Systems	281	(1)
Genetic Disorders and DNA Repair	282	(1)
Mutation, Genotypes, and Phenotypes	282	(1)
Mutation Can Cause a Range of Phenotypes	283	(1)
Genomic Imprinting: Reversible Alterations to the Genome	283	(2)
Case Studies	285	(1)
Summary	286	(1)
Questions and Problems	286	(2)
Internet Activities	288	(1)
For Further Reading	289	(1)
An Introduction to Cloning and Recombinant DNA	290	(23)
What are Clones?	291	(4)
Plants Can Be Cloned from Single Cells	292	(1)
Animals Can Be Cloned by Several Methods	293	(2)
Cloning Genes is a Multistep Process	295	(7)
Restriction Enzymes Cut DNA at Specific Sites	295	(1)
Vectors Serve as Carriers of DNA	296	(2)
Steps in the Process of Cloning DNA	298	(4)
Concepts and Controversies Asilomar: Scientists Get Involved	302	(1)
Cloned Libraries	302	(1)
Finding a Specific Clone in a Library	303	(1)
A Revolution in Cloning: The Polymerase Chain Reaction	303	(2)
Analyzing Cloned Sequences	305	(3)
Southern Blotting	305	(1)
DNA Sequencing	306	(2)
Guest Essay The Human Genome Project: Reading Our Own Genetic Blueprint	308	(1)
Francis Sellers Collins
Case Studies	309	(1)
Summary	310	(1)
Questions and Problems	310	(2)
Internet Activities	312	(1)
For Further Reading	312	(1)
Applications of Recombinant DNA Technology	313	(27)
Recombinant DNA Techniques Have Revolutionized Human Gene Mapping	314	(5)
RFLPs Are Heritable Genetic Markers	315	(2)
Mapping Genes Using RFLPs	317	(1)
Mapping the Gene for Cystic Fibrosis: RFLPs and Positional Cloning	317	(2)
Mapping at the Chromosomal Level	319	(1)
Prenatal and Presymptomatic Testing for Genetic Disorders	319	(3)
Prenatal Testing for Sickle Cell Anemia	320	(1)
Preimplantation Testing	321	(1)
Presymptomatic Testing for Genetic Disorders	321	(1)
DNA Chips and Genetic Testing	321	(1)
DNA Fingerprinting	322	(4)
Minisatellites and VNTRs	323	(1)
Forensic Applications of DNA Fingerprinting	324	(1)
Other Applications of DNA Fingerprinting	325	(1)
Concepts and Controversies Death of a Czar	326	(1)
The Human Genome Project is an international Effort	327	(3)
The Genome Project Has Several Steps	327	(2)
The Human Genome Project: A Progress Report	329	(1)
Gene Transfer Technology Has Many Applications	330	(4)
The Rise of Biotechnology	330	(1)
Bio-Pharming: Making Human Proteins in Animals	330	(2)
Genetic Disorders Can Be Corrected by Gene Therapy	332	(1)
New Plants and Animals Can Be Created by Gene Transfer	333	(1)
Ethical Questions About Cloning and Recombinant DNA	334	(2)
Case Studies	336	(1)
Summary	337	(1)
Questions and Problems	337	(2)
Internet Activities	339	(1)
For Further Reading	339	(1)
Genes and Cancer	340	(27)
Cancers and Malignant Tumors	342	(1)
Mutations in Specific Genes Can Predispose to Cancer	342	(2)
Tumor Suppressor Genes, Oncogenes, and the Cell Cycle	344	(4)
Retinoblastoma Is Caused by Mutation in a Tumor Suppressor Gene	344	(2)
The Search for Breast Cancer Genes	346	(2)
Oncogenes and Cancer	348	(4)
Rous Sarcoma Virus and the Discovery of Oncogenes	348	(2)
The Conversion of Proto-Oncogenes to Oncogenes	350	(2)
A Genetic Model for Cancer: Colon Cancer	352	(2)
Genomic Changes and Cancer	354	(1)
DNA Repair Mutations Can Result in Genomic Instability	354	(1)
Gatekeeper and Caretaker Genes: Insights from Colon Cancer	354	(1)
Chromosome Changes and Cancer	355	(2)
Chromosome Rearrangements and Leukemias	355	(1)
Translocations, Hybird Genes, and Leukemias	356	(1)
Cancer and the Environment	357	(1)
Concepts and Controversies Epidemiology, Asbestos, and Cancer	358	(2)
Epidemiology and Links to Environmental Factors	358	(1)
Occupational Hazards and Cancer Risk	359	(1)
Guest Essay A Journey through Science	360	(2)
Bruce Ames
Environmental Factors and Cancer	360	(1)
Behavior and Cancer	361	(1)
Case Studies	362	(1)
Summary	363	(1)
Questions and Problems	363	(2)
Internet Activities	365	(1)
For Further Reading	365	(2)
Genetics of the Immune System	367	(27)
The Immune System Defends the Body Against Infection	368	(1)
The Inflammatory Responses is a General Reaction	369	(2)
Nonspecific Responses are Activated by the Inflammatory Reaction	369	(1)
The Complement System Kills Microorganisms Directly	370	(1)
The Immune Response is a Specific Defense Against Infection	371	(7)
An Overview of the Immune Response	371	(2)
The Antibody-Mediated Immune Response Involves Several Steps	373	(1)
Antibodies are Molecular Weapons against Antigens	374	(1)
Antibody Genes Undergo Recombination in B Cells	375	(1)
T Cells Mediate the Cellular Immune Response	376	(1)
The Immune System Has a Memory Function	377	(1)
Blood Types are Determined by Cell-Surface Antigens	378	(2)
ABO Blood Typing Allows Safe Blood Transfusions	379	(1)
Rh Blood Types Can Cause Immune Reactions between Mother and Fetus	379	(1)
Organ Transplants Must be Immunologically Matched	380	(3)
Successful Transplants Depend on HLA Matching	381	(1)
Animal-Human Organ Transplants	381	(2)
The HLA System and Disease Associations	383	(1)
Disorders of the Immune System	383	(3)
Overreaction in the Immune System Causes Allergies	383	(2)
Autoimmune Reactions Cause the Immune System to Attack the Body	385	(1)
Genetic Disorders Can Impair the Immune System	385	(1)
Concepts and Controversies Why Bee Stings Can Be Fatal	386	(3)
AIDS Attacks the Immune System	387	(2)
Guest Essay Medicine---A Scientific Safari	389	(1)
M. Michael Glovsky
Case Studies	390	(1)
Summary	390	(1)
Questions and Problems	391	(1)
Internet Activities	392	(1)
For Further Reading	392	(2)
Genetics of Behavior	394	(27)
Models, Methods, and Phenotypes in Studying Behavior	396	(2)
Genetic Models of Inheritance and Behavior	396	(1)
Methods of Studying Behavior Genetics	397	(1)
Concepts and Controversies Is Going to Medical School a Genetic Trait?	398	(1)
Phenotypes: How Is Behavior Defined?	398	(1)
Animal Models: The Search for Behavior Genes	399	(2)
Open-Field Behavior in Mice	399	(1)
Learning in Drosophila	399	(2)
Single-Gene Effects on Human Behavior	401	(3)
Lesch-Nyhan Syndrome Is a Disorder of Nucleic Acid Metabolism	401	(1)
Charcot-Marie-Tooth Disease Affects Nerve Fibers	402	(1)
Huntington Disease Is an Adult Onset Disorder	403	(1)
Single Genes, Aggressive Behavior, and Brain Metabolism	404	(2)
Mapping a Gene for Aggression	405	(1)
Problems with Single-Gene Models	406	(1)
The Genetics of Mood Disorders and Schizophrenia	406	(3)
Mood Disorders: Unipolar and Bipolar Illnesses	406	(2)
Schizophrenia Has a Complex Phenotype	408	(1)
Concepts and Controversies The Link between Madness and Genius	409	(1)
Genetics and Social Behavior	410	(4)
Tourette Syndrome Affects Speech and Behavior	410	(1)
Alzheimer Disease Has Genetic and Nongenetic Components	410	(2)
Alcoholism Has Several Components	412	(1)
Sexual Orientation is a Multifactorial Trait	413	(1)
Guest Essay Neurogenetics: From Mutants to Molecules	414	(1)
Summing Up: The Current Status of Human Behavior Genetics	415	(2)
Case Studies	417	(1)
Summary	417	(1)
Questions and Problems	418	(1)
Internet Activities	419	(1)
For Further Reading	419	(2)
Genes in Populations	421	(20)
The Population as a Genetic Reservoir	423	(2)
Measuring Allele Frequencies in Populations	425	(2)
Codominant Allele Frequencies Can Be Measured Directly	425	(1)
Recessive Allele Frequencies Cannot by Measured Directly	426	(1)
Concepts and Controversies The Thrifty Genotype	427	(1)
The Hardy-Weinberg Law: Measuring Allele and Genotype Frequencies	427	(2)
Assumptions for the Hardy-Weinberg Law	428	(1)
Calculating Allele and Genotype Frequencies	428	(1)
Populations Can Be in Genetic Equilibrium	429	(1)
Using the Hardy-Weinberg Law in Human Genetics	429	(6)
Autosomal Dominant and Recessive Alleles	430	(1)
Autosomal Codominant Alleles	430	(1)
X-Linked Traits	430	(1)
Multiple Alleles	431	(1)
Estimating the Frequency of Heterozygotes in a Population	431	(4)
Anthropology, Population Structure, and Genetics	435	(3)
Case Studies	438	(1)
Summary	438	(1)
Questions and Problems	439	(1)
Internet Activities	439	(1)
For Further Reading	440	(1)
Human Diversity and Evolution	441	(27)
Measuring Genetic Diversity in Human Populations	442	(5)
New Alleles are Generated by Mutation	443	(1)
Genetic Drift Can Change Allele Frequencies	444	(1)
Natural Selection Acts on Variation in Populations	445	(2)
Selection and the Genetic History of a Population	447	(1)
Natural Selection and the Frequency of Genetic Disorders	447	(1)
Human Activity as a Force in Changing Allele Frequencies	448	(6)
Migration Reduces Genetic Variation between Populations	448	(2)
Mate Selection Is Usually Nonrandom	450	(1)
Culture Is a Force in Altering Allele Frequencies	451	(3)
Genetic Variation in Human Populations	454	(2)
The Spread of Polymorphisms	454	(1)
Measuring Gene Flow among Populations	455	(1)
The Question of Race	456	(2)
Races as Subspecies	457	(1)
Are There Human Races?	457	(1)
Human Genetic Variation: Summing Up	458	(1)
Primate Evolution and Human Origins	458	(4)
Humanlike Hominids Appeared about Four Million Years Ago	458	(2)
The Genus Homo Appeared about Two Million Years Ago	460	(1)
Homo Erectus Originated in Africa	461	(1)
Concepts and Controversies Tool Time: Did Homo erectus Use Killer Frisbees?	462	(1)
The Appearance and Spread of Homo Sapiens	463	(2)
Two Theories Differ on How and Where Homo sapiens Originated	463	(1)
The Spread of Humans Across the World	464	(1)
Case Studies	465	(1)
Summary	465	(1)
Questions and Problems	466	(1)
Internet Activities	466	(1)
For Further Reading	467	(1)
Genetic Screening and Genetic Counseling	468	(20)
Genetic Screening	469	(5)
Newborn and Carrier Screening	470	(2)
Occupational Screening	472	(1)
Reproductive Screening	473	(1)
Prenatal Testing	474	(4)
Ultrasonography	475	(1)
Fetoscopy	476	(1)
Testing Embryonic Blastomeres	476	(1)
Risks and Problems Associated with Prenatal Testing	477	(1)
Genetic Counseling	478	(1)
Who are Genetic Counselors?	478	(1)
Concepts and Controversies The Business of Making Babies	479	(3)
Reasons to Seek Genetic Counseling	480	(1)
How Does Genetic Counseling Work?	480	(2)
Future Directions	482	(1)
The Impact of Genetic Testing and Genetic Screening	482	(3)
Personal Consequences	482	(1)
Social Consequences	483	(1)
Legal Implications	484	(1)
Case Studies	485	(1)
Summary	485	(1)
Questions and Problems	486	(1)
Internet Activities	487	(1)
For Further Reading	488
Appendix A Probability	A-a
Appendix B Answers to Selected Questions and Problems	B-a
Glossary	G-a
Credits	C-a
Index	I-a