Presentation on theme: "Biological Beginnings"— Presentation transcript:
1 Biological Beginnings The Evolutionary PerspectiveGenetic Foundations of DevelopmentHeredity and Environment interaction:The Nature-Nurture DebatePrenatal DevelopmentBirth
2 The Evolutionary Perspective Natural selection and adaptive behavior:Darwin and his observations.All organisms must adapt in life.Evolutionary psychology:Emphasizes adaptation, reproduction,and survival of the fittest in shaping behavior.Evolution explains human physical featuresand behaviors.
3 The Evolutionary Perspective Natural selection and adaptive behavior:Darwin and his observations.All organisms must adapt in life.Evolutionary psychology:Emphasizes adaptation, reproduction,and survival of the fittest in shaping behavior.Evolution explains human physical features and behaviors.Explaining humans and their behavior:Larger brains and more complex societies.Takes longest of all mammals to mature.Some evolved mechanisms of adaptation notcompatible with modern society.
4 Evolution and Life-Span Development The Evolutionary PerspectiveEvolution and Life-Span DevelopmentBenefits of evolutionary selection decrease with age.As adults weaken biologically, culture-based needs increase.
5 Genetic Foundations of Development DNA: Deoxyribonucleic AcidChromosomes: Thread-like structuresGenes: Units of hereditary informationHuman Genome Project: 30,000 genes in humans.
6 Cells, Chromosomes, Genes, and DNA Genetic FoundationsCells, Chromosomes, Genes, and DNANucleus (center of cell) contains chromosomes and genesGene: a segment of DNA (spiraled double chain) containing the hereditary codeChromosomes are threadlike structures composed of DNA molecules
7 The Collaborative Gene Genetic FoundationsThe Collaborative GeneMitosis: Cell nucleus duplicates.Meiosis: Cell division forms gametes.Fertilization: Egg and sperm form zygote.Genetic variability in the population.X and Y chromosomes determine sex.Genes and chromosomes:Identical and fraternal twinsMutated geneGenotype-All of one’s genetic makeupPhenotype-Observable characteristics
8 Genetic Principles Sex-linked genes: Genetic FoundationsGenetic PrinciplesSex-linked genes:X-linked inheritance for males and females.Poly-genetically determined characteristics:Many genes interact to influence a trait.Sex-linked chromosome abnormalities:Down SyndromeKlinefelter syndrome- (males-extra X chromosome)Fragile X syndrome- (abnormality in X chromosome)Turner syndrome- (females-extra X chromosome)XYY syndrome- (males-extra Y chromosome)
9 Gene-Linked Abnormalities Genetic FoundationsGene-Linked AbnormalitiesPKU: phenylketonuriaSickle-cell anemiaCystic fibrosisDiabetesHemophiliaGenetic disorders can sometimes becompensated for by other genes or events.Behavior Genetics:Studies influence of heredity and environment on individual differences.Studies use twins or adoptees:Monozygotic and dizygotic twins.Adoption study: examine behavior and psychological characteristics.
10 Heredity-Environment Correlations Heredity, Environment, and Individual DifferencesHeredity-Environment CorrelationsIn infancy, environment mostly controlled by parents.As children age, their experiences extendmore beyond the family’s influence.
11 The Course of Prenatal Development Germinal period: 2 weeks after conceptionEmbryonic period: 2 to 8 weeks after conceptionThree layers: endodem, mesoderm, ectodermUmbilical cord connect to placentaOrganogenesisFetal periodFrom 2 months after conception to birthTrimesters of pregnancy
12 The three trimesters of prenatal development Second trimesterThird trimesterFirst trimester0 - 4 weeksLess than 1 inch long12 weeks32 weeks8 weeksLess than 1/10th of inch long16½ -18 inches, wt: 4-5 lbs3 inches long, wt: 1 ounce16 weeks5.5 inches long, wt: 4 ounces20 weeks10-12 inches, wt: ½ -1 lbs24 weeks11-14 inches, wt: 1-1½ lbs36-38 weeks28 weeks19 inches, wt: 6 lbs14-17 inches, wt: 2½ -3 lbs
13 Prenatal Diagnostic Tests Prenatal DevelopmentPrenatal Diagnostic TestsUltrasound SonographyChorionic Villi Sampling:Small sample of placenta taken.Amniocentesis:Samples amniotic fluid.Maternal blood test
14 Hazards to Prenatal Development Teratogen: Agent causing birth defects.Severity of damage affected by:DoseGenetic susceptibilityTime of exposure
15 Teratogen Types of Teratogens Adverse Effects Prescription Drugs: Adverse EffectsPrescription Drugs:ThalidomideArm and leg malformationWarfarinMental retardation, microcephaly(abnormally small head)TrimethadioneDevelopmental delay, ‘V’-shaped eyebrows, cleft lip and/or palateTetracyclineTooth malformationsSubstances of Abuse:HeroinFetal/newborn addiction, slower growthCocaineGrowth retardation; possible long-term behavioral effectsSolventsMicrocephalySocial Drugs:AlcoholFetal alcohol syndrome, fetal alcohol effectsSmokingSpontaneous abortion, growth retardationCaffeineFew human studies. high doses induce abnormalities in animals.Disease:RubellaCataracts, deafness, heart defectsHerpes SimplexMicrocephaly, microophthalmia (abnormally small or absent eyes, associated with blindness)Teratogen
17 Hazards to Prenatal Development Psychoactive drugs:CaffeineAlcohol and fetal alcohol syndrome (FAS)Nicotine’s link to SIDS, ADHD, low birth weightEffect of father’s smokingCocaine, marijuana, and heroinMethamphetamineEnvironmental hazards and pollutants.Incompatible blood types of parents:Rh-positive and Rh-negativeMaternal diseases like German measles, syphilis, HIV and AIDSOther prenatal factors:Nutrition, prenatal education and careMaternal age and risksMaternal emotional states and stressPaternal factorsEnvironmental factors
18 Prenatal Care Prenatal programs: Education Medical care BirthPrenatal CarePrenatal programs:EducationMedical careSocial and nutritional servicesLow birth weight and infant mortality ratesView of pregancy vary among culturesand ethnic groups
19 The Birth Process Stages of birth: Stage 1-Uterine contractions Stage 2-Baby’s head moves through birthcanalStage 3-Afterbirth when placenta,umbilical cord, and other membranesare detached and expelled
20 Strategies for Childbirth Home delivery, birthing center, or hospital?99% of all U.S. births occur in hospitalsHome births more common outside U.S.Doula as caregiverRole of midwife, nurse, and physician
21 BirthMethods of DeliveryMedication with analgesics (epidural block, oxytocics, etc.)Possible effects of drugs on fetusNatural childbirthPrepared childbirth and the Lamaze methodCesarean sections for breech babies,other risks and benefitsNonmedicated techniques:Waterbirth more in European countriesMassage reduces pain and anxietyAcupuncture is standard in ChinaHypnosis has some positive effectsMusic therapy reduces stress, manages pain
22 BirthAssessing the NewbornApgar Scale: Evaluates heart, reflexes, and color.Brazelton Neonatal Behavioral Assessment Scale (BNBAS): Sensitive index of neurological competence.Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS): Analysis of behavior, neurological and stress responses, and regulatory capacities.
23 Low Birth Weight and Preterm Low birth weight infants:Weigh less than 5.5 lbsVery low birth weight:Less than 3 lbsPreterm infants:35 or fewer weeks after conception (about 12% of U.S. births)Kangaroo care:Hold infant to promote skin-to-skin contact between infant and caregiver to promote-Better breathingLonger sleep periodsWeight gainLess cryingLonger periods of alertness
24 Massage Therapy Leeds to 47% greater weight gain for preterm infants. BirthMassage TherapyLeeds to 47% greater weight gain for preterm infants.Other Benefits:Labor painAsthmaADHDArthritisAutistic children