Chapter 2 Biological Beginnings.pptx

BIOLOGICAL BEGINNINGS 2  CHAPTER OUTLINE The evolutionary perspective Genetic foundations of development The interaction of heredity and environment: The nature-nurture debate Prenatal development Birth and the postpartum period...

BIOLOGICAL BEGINNINGS 2  CHAPTER OUTLINE The evolutionary perspective Genetic foundations of development The interaction of heredity and environment: The nature-nurture debate Prenatal development Birth and the postpartum period 2-2 THE EVOLUTIONARY PERSPECTIVE Natural selection and adaptive behavior Evolutionary psychology 2-3 NATURAL SELECTION AND ADAPTIVE BEHAVIOR Natural selection - Evolutionary process by which those individuals of a species that are best adapted are the ones that survive and reproduce Adaptive behavior - Promotes an organism’s survival in the natural habitat 2-4  EVOLUTIONARY PSYCHOLOGY Emphasizes the importance of adaptation, reproduction, and survival of the fittest in shaping behavior Evolutionary developmental psychology Interest has grown in using the concepts of evolutionary psychology to understand human development Psychological mechanisms are domain-specific 2-5  EVOLUTIONARY PSYCHOLOGY Evaluation Evolution gave us biological potentialities but it does not dictate behavior People have used their biological capacities to produce diverse cultures Aggressive and peace-loving, egalitarian and autocratic Studying specific genes in humans and other species and their links to traits and behaviors Best approach for testing ideas coming out of evolutionary psychology 2-6  GENETIC FOUNDATIONS OF DEVELOPMENT Genes and chromosomes Genetic principles Chromosome and gene-linked abnormalities 2-7  GENETIC FOUNDATIONS OF DEVELOPMENT Human life begins as a single cell Nucleus of each cell contains chromosomes Chromosomes: Threadlike structures made up of deoxyribonucleic acid DNA: A complex double-helix molecule that contains genetic information Genes: Units of hereditary information, are short segments of DNA 2-8 FIGURE 2.2 - CELLS, CHROMOSOMES, DNA, AND GENES 2-9  GENETIC FOUNDATIONS OF DEVELOPMENT Human genome consists of many genes that collaborate: Both with each other and with nongenetic factors inside and outside the body Activity of genes is affected by their environment Stress, radiation, and temperature can influence gene expression Exposure to radiation changed the rate of DNA synthesis in cells 2-10  GENES AND CHROMOSOMES Mitosis, meiosis, and fertilization Mitosis: Reproduction of cells Meiosis: Cell division that forms sperm and eggs (gametes) Fertilization: A stage in reproduction when an egg and a sperm fuse to create a single cell, called a zygote Zygote: A single cell formed through fertilization 2-11 FIGURE 2.3 - THE GENETIC DIFFERENCE BETWEEN MALES AND FEMALES 2-12  GENES AND CHROMOSOMES Sources of variability Combining the genes of two parents in offspring increases genetic variability Important sources of variability: Chromosomes in the zygote are not exact copies of those in the mother’s ovaries and the father’s testes DNA 2-13  GENES AND CHROMOSOMES Mutated gene - Permanently altered segment of DNA Genotype: Genetic heritage 2-14  GENES AND CHROMOSOMES Susceptibility genes - Make the individual more vulnerable to specific diseases or accelerated aging Longevity genes - Make the individual less vulnerable to certain diseases and more likely to live to an older age Phenotype: Way an individual’s genotype is expressed in observed and measurable characteristics 2-15  GENETIC PRINCIPLES Dominant and recessive genes principle One gene of a pair always exerts its effects (dominant), overriding the potential influence of the other gene (recessive) Sex-linked genes When a mutated gene is carried on the X chromosome, the result is called X-linked inheritance 2-16  GENETIC PRINCIPLES Polygenic inheritance Polygenically determined by the interaction of many different genes Gene-gene interaction - Studies that focus on the interdependence of two or more genes in: Influencing characteristics, behavior, diseases, and development 2-17 FIGURE 2.4 - SOME CHROMOSOME ABNORMALITIES 2-18  SEX-LINKED CHROMOSOME ABNORMALITIES Klinefelter syndrome Genetic disorder in which males have an extra X chromosome, making them XXY instead of XY Fragile X syndrome Genetic disorder that results from an abnormality in the X chromosome, which becomes constricted and often breaks 2-19  SEX-LINKED CHROMOSOME ABNORMALITIES Turner syndrome Chromosome disorder in females in which either an X chromosome is missing, making the person XO instead of XX, or part of one X chromosome is deleted XYY syndrome Chromosomal disorder in which the male has an extra Y chromosome 2-20  GENE-LINKED ABNORMALITIES Phenylketonuria (PKU) Metabolic disorder that, left untreated, causes mental retardation Sickle-cell anemia Blood disorder that limits the body’s oxygen supply Can cause joint swelling, as well as heart and kidney failure 2-21 GENE-LINKED ABNORMALITIES Cystic fibrosis Diabetes Hemophilia Huntington disease Spina bifida Tay-Sachs disease 2-22  THE INTERACTION OF HEREDITY AND ENVIRONMENT: THE NATURE-NURTURE DEBATE Behavior genetics Heredity-environment correlations The epigenetic view and gene x environment (GXE) interaction Conclusions about heredity- environment interaction 2-23  BEHAVIOR GENETICS Seeks to discover the influence of heredity and environment on individual differences in human traits and development Twin study: Behavioral similarity of identical and fraternal twins is compared Adoption study: Seek to discover whether, in behavior and psychological characteristics, adopted children are: More like their adoptive parents, who provided a home environment More like their biological parents, who contributed their heredity 2-24  HEREDITY-ENVIRONMENT CORRELATIONS Passive genotype-environment correlations Occur because biological parents, who are genetically related to the child, provide a rearing environment for the child Evocative genotype-environment correlations Occur because a child’s characteristics elicit certain types of environments 2-25  HEREDITY-ENVIRONMENT CORRELATIONS Active (niche-picking) genotype- environment correlations Occur when children seek out environments that they find compatible and stimulating Niche-picking - Refers to finding a setting that is suited to one’s abilities 2-26  EPIGENETIC VIEW AND GENE × ENVIRONMENT (G × E) INTERACTION Epigenetic view: Development is the result of an ongoing, bidirectional interchange between heredity and environment 2-27  FIGURE 2.6 - COMPARISON OF THE HEREDITY - ENVIRONMENT CORRELATION AND EPIGENETIC VIEWS 2-28 HEREDITY-ENVIRONMENT INTERACTION: THE NATURE- NURTURE DEBATE Gene X environment (G X E) interaction: Interaction of: Specific measured variation in the DNA Specific measured aspect of the environment 2-29  CONCLUSIONS ABOUT HEREDITY- ENVIRONMENT INTERACTION Relative contributions of heredity and environment are not additive Complex behaviors have some genetic loading Gives each individual a propensity for a particular developmental trajectory 2-30  PRENATAL DEVELOPMENT The course of prenatal development Prenatal tests Infertility and reproductive technology Hazards to prenatal development Prenatal care 2-31  THE COURSE OF PRENATAL DEVELOPMENT Germinal period: Takes place in the first two weeks after conception Includes: Creation of fertilized egg (the zygote) Cell division Attachment of the multicellular organism to the uterine wall 2-32 FIGURE 2.7 - MAJOR DEVELOPMENTS IN THE GERMINAL PERIOD 2-33  THE COURSE OF PRENATAL DEVELOPMENT Embryonic period: Occurs from two to eight weeks after conception Rate of cell differentiation intensifies Support systems for cells form Organs appear Organogenesis: Name given to the process of organ formation during the first two months of prenatal development 2-34  THE COURSE OF PRENATAL DEVELOPMENT Fetal period: Extends from two months after conception until birth in typical pregnancies Lasts about seven months Growth and development continue their dramatic course during this time 2-35 FIGURE 2.8 - GROWTH AND DEVELOPMENT IN THE THREE TRIMESTERS OF PRENATAL DEVELOPMENT 2-36 FIGURE 2.9 - EARLY FORMATION OF THE NERVOUS SYSTEM 2-37  PRENATAL TESTS Ultrasound sonography Chorionic villus sampling Amniocentesis Maternal blood screening Fetal MRI Noninvasive prenatal diagnosis (NIPD) 2-38  INFERTILITY AND REPRODUCTIVE TECHNOLOGY Infertility - Inability to conceive a child after 12 months of regular intercourse without contraception In vitro fertilization (IVF) - Eggs and sperm are combined in a laboratory dish Fertilized egg is transferred into the woman’s uterus 2-39  HAZARDS TO PRENATAL DEVELOPMENT General principles Teratogen: Any agent that can potentially cause a birth defect or negatively alter cognitive and behavioral outcomes Prescription and nonprescription drugs 2-40  HAZARDS TO PRENATAL DEVELOPMENT Psychoactive drugs Caffeine Alcohol Fetal alcohol spectrum disorders (FASD): A cluster of abnormalities and problems that appear in the offspring of mothers who drink alcohol heavily during pregnancy Nicotine Cocaine Methamphetamine Marijuana Heroin 2-41  HAZARDS TO PRENATAL DEVELOPMENT Incompatible blood types Environmental hazards Maternal diseases Other parental factors Maternal diet and nutrition Maternal age Emotional states and stress Paternal factors 2-42  PRENATAL CARE Varies enormously from one woman to another Usually involves: Defined schedule of visits for medical care which includes screening for: Manageable conditions Treatable diseases that can affect the baby or the mother Comprehensive educational, social, and nutritional services 2-43 BIRTH AND THE POSTPARTUM PERIOD The birth process The transition from fetus to newborn Low birth weight and preterm infants Bonding The postpartum period 2-44 BIRTH AND THE POSTPARTUM PERIOD The birth process - Occurs in three processes First stage is the longest Uterine contractions are 15 to 20 minutes apart at the beginning and last up to a minute Second birth stage - When the baby’s head starts to move through the cervix and the birth canal Terminates when the baby completely emerges from the mother’s body Third stage - Afterbirth Placenta, umbilical cord, and other membranes are detached and expelled 2-45 BIRTH AND THE POSTPARTUM PERIOD Childbirth setting and attendants Who helps a mother during birth varies across cultures Midwives Doulas - A caregiver who provides continuous physical, emotional, and educational support for the mother before, during, and after childbirth 2-46  METHODS OF CHILDBIRTH Medication Analgesia - Used to relieve pain Include tranquilizers, barbiturates, and narcotics such as Demerol Anesthesia - Used in late first-stage labor and during delivery to block sensation in an area of the body or to block consciousness Oxytocin - Synthetic hormone used to stimulate contractions Pitocin is the most widely used oxytocin 2-47  METHODS OF CHILDBIRTH Natural childbirth: Method in which no drugs are given to relieve pain or assist in the birth process Prepared childbirth: Includes a special breathing technique to control pushing in the final stages of labor As well as more detailed education about anatomy and physiology Lamaze method 2-48  METHODS OF CHILDBIRTH Other nonmedicated techniques to reduce pain Cesarean delivery - The baby is removed from the uterus through an incision made in the mother’s abdomen 2-49  THE TRANSITION FROM FETUS TO NEWBORN Birth involves considerable stress for the baby If the delivery takes too long, the baby can develop anoxia A condition in which the fetus or newborn has an insufficient supply of oxygen Can cause brain damage 2-50  THE TRANSITION FROM FETUS TO NEWBORN Apgar scale: Widely used to assess the health of newborns at one and five minutes after birth Evaluates infants’ heart rate, respiratory effort, muscle tone, body color, and reflex irritability 2-51  LOW BIRTH WEIGHT AND PRETERM INFANTS Conditions that pose threats to many newborns: Low birth weight infants - Weigh less than 5 pounds at birth Very low birth weight newborns - Weigh under 3 pounds Extremely low birth weight newborns - Weigh under 2 pounds 2-52  LOW BIRTH WEIGHT AND PRETERM INFANTS Preterm infants - Born three weeks or more before the pregnancy has reached its full term Small for date infants (small for gestational age infants) - Birth weight that is below normal when the length of the pregnancy is considered Incidence and causes of low birth weight - Varies considerably from one country to another 2-53  LOW BIRTH WEIGHT AND PRETERM INFANTS Consequences of low birth weight - More health and developmental problems than normal birth weight infants Learning disability Attention deficit hyperactivity disorder Breathing problems such as asthma Nurturing includes: Kangaroo care Massage therapy 2-54  BONDIN G The formation of a connection, especially a physical bond between parents and the newborn in the period shortly after birth 2-55  THE POSTPARTUM PERIOD The period after childbirth or delivery that lasts for about six weeks Or until the mother’s body has completed its adjustment and has returned to a nearly prepregnant state Physical adjustments Emotional and psychological adjustments 2-56