Transcript Biological Beginnings

Biological Beginnings
 The Evolutionary Perspective
 Genetic Foundations of Development
 Heredity and Environment interaction:
The Nature-Nurture Debate

 Prenatal Development
 Birth
The Evolutionary Perspective
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.
The Evolutionary Perspective
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.
The Evolutionary Perspective
Evolution and Life-Span
Development
 Benefits of evolutionary selection decrease with age.
 As adults weaken biologically, culture-based needs increase.
Genetic Foundations
Genetic Foundations of
Development
 DNA: Deoxyribonucleic Acid
 Chromosomes: Thread-like structures
 Genes: Units of hereditary information
 Human Genome Project: 30,000 genes in humans.
Genetic Foundations
Cells, Chromosomes, Genes, and DNA
Nucleus (center of
cell) contains
chromosomes
and genes
Chromosomes are
threadlike structures
composed of DNA
molecules
Gene: a segment of DNA
(spiraled double chain)
containing the hereditary
code
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
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)
Genetic Foundations
Gene-Linked Abnormalities
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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.
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.
Prenatal Development
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
Prenatal Development
The three trimesters of prenatal development
0 - 4 weeks
First
trimester
8 weeks
Less than 1/10th of inch long
Less than 1 inch long
12 weeks
3 inches long, wt: 1 ounce
16 weeks
5.5 inches long, wt: 4 ounces
Second
trimester 20 weeks
10-12 inches, wt: ½ -1 lbs
24 weeks
11-14 inches, wt: 1-1½ lbs
28 weeks
14-17 inches, wt: 2½ -3 lbs
Third
trimester 32 weeks
16½ -18 inches, wt: 4-5 lbs
36-38 weeks 19 inches, wt: 6 lbs
Prenatal Development
Prenatal Diagnostic Tests
 Ultrasound Sonography
 Chorionic Villi Sampling:
 Small sample of placenta taken.
 Amniocentesis:
 Samples amniotic fluid.
 Maternal blood test
Prenatal Development
Hazards to Prenatal
Development
 Teratogen: Agent causing birth defects.
 Severity of damage affected by:
 Dose
 Genetic susceptibility
 Time of exposure
Types of Teratogens
Adverse Effects
Prescription Drugs:
Thalidomide
Substances of Abuse:
Social Drugs:
Disease:
Teratogen
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
Heroin
Fetal/newborn addiction, slower growth
Cocaine
Growth retardation; possible long-term
behavioral effects
Solvents
Microcephaly
Alcohol
Fetal alcohol syndrome, fetal alcohol
effects
Smoking
Spontaneous abortion, growth
retardation
Caffeine
Few human studies. high doses induce
abnormalities in animals.
Rubella
Cataracts, deafness, heart defects
Herpes Simplex
Microcephaly, microophthalmia
(abnormally small or absent eyes,
associated with blindness)
Prenatal Development
Prenatal Development
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
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
Birth
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
Birth
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
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
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.
Birth
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
Birth
Massage Therapy
 Leeds to 47% greater weight gain for preterm infants.
 Other Benefits:
 Labor pain
 Asthma
 ADHD
 Arthritis
 Autistic children