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
The Evolutionary Perspective
Evolutionary Developmental
Psychology
 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
 Natural selection failures: harmful conditions and non-
adaptivecharacteristics
 As adults weaken biologically, culture-based needs increase
 Alternative: ‘bi-directional view’
The Evolutionary Perspective
Baltes’ view of evolution and culture
across the life span
The Evolutionary Perspective
Evaluating Evolutionary
Psychology
 Remains just one theoretical approach.
 Evolution does not dictate behavior.
 Biology allows broad range of cultural possibilities.
Genetic Foundations
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
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
 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 genes
 X-linked inheritance for males and females
 Genetic imprinting
 Imprinted gene dominates
 Poly-genetically determined characteristics
 Many genes interact to influence a trait
Genetic Foundations
How brownhaired parents
can have a
blond-haired
child: the gene
for blond hair is
recessive
B B
B Brown
hair
Blond
b hair
Father
Bb
B b
Mother
Bb
B b
b b
Genetic Foundations
Genetic Principles
 Chromosome abnormalities
 Down syndrome
 Sex-linked chromosome
abnormalities
 Klinefelter syndrome
 Fragile X syndrome
 Turner syndrome
 XYY syndrome
Genetic Foundations
Sex-Linked
Chromosome Abnormalities
Klinefelter
Syndrome
Males have an extra X chromosome
Fragile X
syndrome
Abnormality in the X chromosome
Turner
syndrome
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
Heredity, Environment, and Individual Differences
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 analyzed
 Commonalities 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 analyzed
 Commonalities between children attributed to
heredity-environment interaction
Heredity, Environment, and Individual Differences
The Heredity-Environment and
Epigenetic Views
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
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 by
 Dose
 Genetic susceptibility
 Time of exposure
 Effects of prescription and
nonprescription drugs
Prenatal Development
Teratogens and Timing of Their Effects on
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
Prenatal Development
Hazards to Prenatal
Development
 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: occurs in three stages
 Uterine contractions
 Baby’s head moves through birth canal
 Afterbirth 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
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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 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: heart, reflexes, and color
 Brazelton Neonatal Behavioral
Assessment Scale (BNBAS)
 A sensitive index of neurological competence
 Four categories in global terms
 Neonatal Intensive Care Unit Network
Neurobehavioral Scale (NNNS)
 Analysis of behavior, neurological and stress
responses, and regulatory capacities
Birth
The
Apgar
Scale
Birth
Low Birth Weight and Preterm
 Low birth weight infants in U.S. and world
 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)
 Small-for-date infants: weigh less than they
should
 Ethnic variations characterize preterm birth
 Causes and consequences
Birth
Low Birth Weight and Preterm
 Low birth weight infants in U.S. and world
 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)
 Small-for-date infants: weigh less than they
should
 Ethnic variations characterize preterm birth
 Causes and consequences
Birth
Kangaroo Care and Massage
Therapy
 Kangaroo care
 Holds infant to promote skin-to-skin contact
between infant and caregiver
 Can 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
Weight Gain
Comparison of
Premature
Infants Who
Were Massaged
and Not
Massaged
Birth
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