biological beginnings the evolutionary perspective genetic foundations of development heredity...
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Biological Beginnings
The Evolutionary Perspective
Genetic Foundations of Development
Heredity and Environment interaction: The Nature-Nurture Debate
Prenatal Development
Birth
The Evolutionary Perspective
Natural selection and adaptive behaviorDarwin and his observationsAll organisms must adapt in life
Evolutionary psychologyEmphasizes adaptation, reproduction,
and survival of the fittest in shaping behaviorEvolution explains human physical features
and behaviors
The Evolutionary Perspective
The Evolutionary Perspective
Natural selection and adaptive behaviorDarwin and his observationsAll organisms must adapt in life
Evolutionary psychologyEmphasizes adaptation, reproduction,
and survival of the fittest in shaping behaviorEvolution explains human physical features and
behaviors
The Evolutionary Perspective
Evolutionary Developmental Psychology
Explaining humans and their behaviorLarger brains and more complex societiesTakes longest of all mammals to matureSome evolved mechanisms of adaptation not
compatible with modern society
The Evolutionary Perspective
Evolution and Life-Span Development
Benefits of evolutionary selection decrease with age Natural selection failures: harmful conditions and non-
adaptivecharacteristics As adults weaken biologically, culture-based needs increase Alternative: ‘bi-directional view’
The Evolutionary Perspective
The Evolutionary Perspective
Baltes’ view of evolution and culture across the life span
Evaluating Evolutionary Psychology
Remains just one theoretical approach.
Evolution does not dictate behavior.
Biology allows broad range of cultural possibilities.
The Evolutionary Perspective
Genetic Foundations of Development
DNA and the collaborative gene
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
Genetic Foundations
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
The Collaborative Gene Genes and chromosomes
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
Genetic Foundations
The Collaborative Gene
Genes and chromosomes
Identical and fraternal twins
Mutated gene
Genotype — all of one’s genetic makeup
Phenotype — observable characteristics
Genetic Foundations
Genetic Principles
Dominant and recessive genes
Sex-linked genesX-linked inheritance for males and females
Genetic imprintingImprinted gene dominates
Poly-genetically determined characteristicsMany genes interact to influence a trait
Genetic Foundations
Genetic Foundations
b bB bB bB B
b
B
Blond hair
Brown hair
How brown-haired parents
can have a blond-haired
child: the gene for blond hair is
recessiveMother
B bFather
B b
Genetic Foundations
Genetic Principles
Chromosome abnormalitiesDown syndrome
Sex-linked chromosome abnormalities Klinefelter syndrome
Fragile X syndrome
Turner syndrome
XYY syndrome
Sex-Linked Chromosome Abnormalities
Genetic Foundations
KlinefelterSyndrome
Fragile X syndrome
Turner syndrome
Males have an extra X chromosome
Abnormality in the X chromosome
Females missing an X chromosome
XYY syndrome Males have an extra Y chromosome
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
Nature-Nurture Debate
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
Shared environments are analyzedCommonalities between children attributed to heredity-
environment interaction
Heredity, Environment, and Individual Differences
Heredity-Environment Correlations
Passive genotype-environment correlations
Evocative genotype-environment correlations
Active (niche-picking) genotype-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
Shared environments are analyzedCommonalities between children attributed to
heredity-environment interaction
Heredity, Environment, and Individual Differences
The Heredity-Environment and Epigenetic Views
Heredity, Environment, and Individual Differences
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
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
The three trimesters of prenatal development
Prenatal Development
Prenatal Diagnostic Tests Ultrasound sonography
Chorionic villi sampling: small sample of placenta taken
Amniocentesis: samples amniotic fluid
Maternal blood test
Prenatal Development
The Brain
Neurons – 100 billion
Birth defects and neural tube
Neuronal migration occurs
Prenatal Development
Hazards to Prenatal Development
Teratogen: agent causing birth defects
Severity of damage affected byDose Genetic susceptibilityTime of exposure
Effects of prescription and
nonprescription drugs
Prenatal Development
Prenatal Development
Teratogens and Timing of Their Effects on Prenatal Development
Hazards to Prenatal Development
Psychoactive drugsCaffeineAlcohol and fetal alcohol syndrome (FAS)Nicotine’s link to SIDS, ADHD, low birth weightEffect of father’s smokingCocaine, marijuana, and heroinMethamphetamine
Environmental hazards and pollutants
Prenatal Development
Hazards to Prenatal Development
Incompatible blood types of parentsRh-positive and Rh-negativeMaternal diseases like German measles, syphilis, HIV
and AIDS Other prenatal factors
Nutrition, prenatal education and careMaternal age and risksMaternal emotional states and stressPaternal factorsEnvironmental factors
Prenatal Development
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: occurs in three stages
Uterine contractionsBaby’s head moves through birth canalAfterbirth when placenta, umbilical cord,
and other membranes are detached
and expelled Baby must withstand stress of birth
Birth
Strategies for Childbirth Deciding what setting, who attends, and what technique will
be used 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
Birth
Methods of Delivery
Nonmedicated techniquesWaterbirth 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: heart, reflexes, and color
Brazelton Neonatal Behavioral Assessment Scale (BNBAS)A sensitive index of neurological competenceFour categories in global terms
Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS)Analysis of behavior, neurological and stress
responses, and regulatory capacities
Birth
Birth
The Apgar Scale
Low Birth Weight and Preterm
Low birth weight infants in U.S. and worldWeigh 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)Small-for-date infants: weigh less than they
shouldEthnic variations characterize preterm birth
Causes and consequences
Birth
Low Birth Weight and Preterm
Low birth weight infants in U.S. and worldWeigh 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)Small-for-date infants: weigh less than they
shouldEthnic variations characterize preterm birth
Causes and consequences
Birth
Kangaroo Care and Massage Therapy
Kangaroo careHolds infant to promote skin-to-skin contact
between infant and caregiverCan promote
• Better breathing
• Longer sleep periods
• Weight gain
• Less crying
• Longer periods of alertness
Birth
Tiffany Field’s Research on Massage Therapy
Massage therapy led to 47% greater weight gain for preterm infants
Also demonstrated benefits of massage for Labor pain Asthma ADHD Arthritis Autistic children
Birth
Birth
Weight Gain Comparison of
Premature Infants Who
Were Massaged and Not
Massaged
Bonding
Needs to occur shortly after birth
Early emotional attachments may create healthy interactions after leaving hospital
Rooming-in arrangements offered
Massages and tactile stimulation for premature infants affect development
Birth