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Biological Beginnings

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Presentation on theme: "Biological Beginnings"— Presentation transcript:

1 Biological Beginnings
The Evolutionary Perspective Genetic Foundations of Development Heredity and Environment interaction: The Nature-Nurture Debate Prenatal Development Birth

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 features and 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 not compatible with modern society.

4 Evolution and Life-Span Development
The Evolutionary Perspective Evolution and Life-Span Development Benefits of evolutionary selection decrease with age. As adults weaken biologically, culture-based needs increase.

5 Genetic Foundations of Development
DNA: Deoxyribonucleic Acid Chromosomes: Thread-like structures Genes: Units of hereditary information Human Genome Project: 30,000 genes in humans.

6 Cells, Chromosomes, Genes, and DNA
Genetic Foundations Cells, Chromosomes, Genes, and DNA Nucleus (center of cell) contains chromosomes and genes Gene: a segment of DNA (spiraled double chain) containing the hereditary code Chromosomes are threadlike structures composed of DNA molecules

7 The Collaborative Gene
Genetic Foundations The Collaborative Gene Mitosis: 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 twins Mutated gene Genotype-All of one’s genetic makeup Phenotype-Observable characteristics

8 Genetic Principles Sex-linked genes:
Genetic Foundations Genetic Principles Sex-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 Syndrome Klinefelter 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 Foundations Gene-Linked Abnormalities PKU: phenylketonuria Sickle-cell anemia Cystic fibrosis Diabetes Hemophilia Genetic disorders can sometimes be compensated 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 Differences Heredity-Environment Correlations In infancy, environment mostly controlled by parents. As children age, their experiences extend more beyond the family’s influence.

11 The Course of Prenatal Development
Germinal period: 2 weeks after conception Embryonic period: 2 to 8 weeks after conception Three layers: endodem, mesoderm, ectoderm Umbilical cord connect to placenta Organogenesis Fetal period From 2 months after conception to birth Trimesters of pregnancy

12 The three trimesters of prenatal development
Second trimester Third trimester First trimester 0 - 4 weeks Less than 1 inch long 12 weeks 32 weeks 8 weeks Less than 1/10th of inch long 16½ -18 inches, wt: 4-5 lbs 3 inches long, wt: 1 ounce 16 weeks 5.5 inches long, wt: 4 ounces 20 weeks 10-12 inches, wt: ½ -1 lbs 24 weeks 11-14 inches, wt: 1-1½ lbs 36-38 weeks 28 weeks 19 inches, wt: 6 lbs 14-17 inches, wt: 2½ -3 lbs

13 Prenatal Diagnostic Tests
Prenatal Development Prenatal Diagnostic Tests Ultrasound Sonography Chorionic 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: Dose Genetic susceptibility Time of exposure

15 Teratogen Types of Teratogens Adverse Effects Prescription Drugs:
Adverse Effects Prescription Drugs: Thalidomide Arm and leg malformation Warfarin Mental retardation, microcephaly(abnormally small head) Trimethadione Developmental delay, ‘V’-shaped eyebrows, cleft lip and/or palate Tetracycline Tooth malformations Substances of Abuse: Heroin Fetal/newborn addiction, slower growth Cocaine Growth retardation; possible long-term behavioral effects Solvents Microcephaly Social Drugs: Alcohol Fetal alcohol syndrome, fetal alcohol effects Smoking Spontaneous abortion, growth retardation Caffeine Few human studies. high doses induce abnormalities in animals. Disease: Rubella Cataracts, deafness, heart defects Herpes Simplex Microcephaly, microophthalmia (abnormally small or absent eyes, associated with blindness) Teratogen

16 Prenatal Development

17 Hazards to Prenatal Development
Psychoactive drugs: Caffeine Alcohol and fetal alcohol syndrome (FAS) Nicotine’s link to SIDS, ADHD, low birth weight Effect of father’s smoking Cocaine, marijuana, and heroin Methamphetamine Environmental hazards and pollutants. Incompatible blood types of parents: Rh-positive and Rh-negative Maternal diseases like German measles, syphilis, HIV and AIDS Other prenatal factors: Nutrition, prenatal education and care Maternal age and risks Maternal emotional states and stress Paternal factors Environmental factors

18 Prenatal Care Prenatal programs: Education Medical care
Birth Prenatal Care Prenatal programs: Education Medical care Social and nutritional services Low birth weight and infant mortality rates View of pregancy vary among cultures and ethnic groups

19 The Birth Process Stages of birth: Stage 1-Uterine contractions
Stage 2-Baby’s head moves through birth canal Stage 3-Afterbirth when placenta, umbilical cord, and other membranes are detached and expelled

20 Strategies for Childbirth
Home delivery, birthing center, or hospital? 99% of all U.S. births occur in hospitals Home births more common outside U.S. Doula as caregiver Role of midwife, nurse, and physician

21 Birth Methods of Delivery Medication with analgesics (epidural block, oxytocics, etc.) Possible effects of drugs on fetus Natural childbirth Prepared childbirth and the Lamaze method Cesarean sections for breech babies, other risks and benefits Nonmedicated techniques: Waterbirth more in European countries Massage reduces pain and anxiety Acupuncture is standard in China Hypnosis has some positive effects Music therapy reduces stress, manages pain

22 Birth Assessing the Newborn Apgar 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 lbs Very low birth weight: Less than 3 lbs Preterm 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 breathing Longer sleep periods Weight gain Less crying Longer periods of alertness

24 Massage Therapy Leeds to 47% greater weight gain for preterm infants.
Birth Massage Therapy Leeds to 47% greater weight gain for preterm infants. Other Benefits: Labor pain Asthma ADHD Arthritis Autistic children

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