The document discusses biological foundations of human development from an evolutionary perspective. It covers topics like natural selection, genetics, gene-linked abnormalities, chromosomal abnormalities, and reproductive challenges. Specifically, it describes several major genetic disorders like cystic fibrosis, sickle-cell anemia, phenylketonuria (PKU), and their associated genetic causes and treatments. It also discusses prenatal diagnostic tests that can assess fetal development and identify potential genetic abnormalities or risks.

1. LIFE-SPAN DEVELOPMENT
Sixteenth Edition
Chapter 2
Biological
Beginnings
Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.

2. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Chapter Outline
• The evolutionary perspective
• Genetic foundations of development
• Reproductive challenges and choices
• Heredity-environment interaction: The nature-
nurture debate

3. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
The Evolutionary Perspective
• Natural selection and adaptive behavior
• Evolutionary psychology

4. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Natural Selection and Adaptive
Behavior
• Natural selection - Evolutionary process by
which individuals of a species that are best
adapted are the ones that survive and
reproduce
• Adaptive behavior - Promotes an organism’s
survival in the natural habitat

5. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Evolutionary Psychology (1 of 3)
• Emphasizes the importance of adaptation,
reproduction, and survival of the fittest in
shaping behavior
• Evolutionary developmental psychology
– Interest has grown in using the concepts of
evolutionary psychology to understand human
development
– Psychological mechanisms are domain-specific

6. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Evolutionary Psychology (2 of 3)
• Connecting evolution and life-span development
– Benefits conferred by evolutionary selection
decrease with age
– Natural selection primarily operates during the
first half of life
– Older adults
 Weaken biologically and need culture-based
resources
o Cognitive skills, literacy, medical technology, and
social support

7. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Evolutionary Psychology (3 of 3)
• Evaluating Evolutionary Psychology
– Evolution gave us biological potentialities but it
does not dictate behavior
 People have used their biological capacities to
produce diverse cultures
o Aggressive and peace-loving, egalitarian and
autocratic
– Evolution occurs on a time scale that does not
lend itself to empirical study
 Studying specific genes in humans and other
species and their links to traits and behaviors is
best approach for testing ideas of evolutionary
psychology

8. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Baltes’ View of Evolution and Culture
Across the Life Span

9. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Genetic Foundations of Development
• The collaborative gene
• Genes and chromosomes
• Genetic principles
• Chromosomal and gene-linked abnormalities

10. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Cells, Chromosomes, DNA, and
Genes

11. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
The Collaborative Gene (1 of 4)
• Human life begins as a single cell
• Nucleus of each cell contains chromosomes
– Chromosomes: Threadlike structures made up of
deoxyribonucleic acid
– DNA: Complex double-helix molecule that
contains genetic information
• Genes: Units of hereditary information
composed of DNA
– Help cells to reproduce themselves
– Manufacture the proteins that maintain life

12. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
The Collaborative Gene (2 of 4)
• Genome-wide association method - Identify
genetic variations linked to a particular disease
• Linkage analysis - Helps discover the location of
a gene or genes in relation to a marker gene
– Used in the search for a disease-related genes

13. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
The Collaborative Gene (3 of 4)
• Next-generation sequencing
– Describes the vast increase in genetic data
generated at a reduced cost and in a shorter
period of time
• Thousand Genomes Project
– Most detailed study of human genetic variation to
date
– Aims to determine the genomic sequences of at
least 1,000 individuals from different ethnic
groups around the world

14. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
The Collaborative Gene (4 of 4)
• Human genome consists of many genes that
collaborate both with each other and with non
genetic factors inside and outside the body
• Activity of genes is affected by their
environment
• Stress, radiation, and temperature can influence
gene expression
– Exposure to radiation changes the rate of DNA
synthesis in cells

15. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
The Genetic Difference Between Males
and Females

16. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Genes and Chromosomes (1 of 4)
• Mitosis: Cellular reproduction in which the cell’s
nucleus duplicates itself with two new cells being
formed
– Each cell contains the same DNA as parent cell
• Meiosis: Cell division that forms sperm and eggs
• Fertilization: Stage in reproduction when an egg
and a sperm fuse to create zygote
– Zygote: Single cell formed through fertilization

17. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Genes and Chromosomes (2 of 4)
• Sources of variability
– Combining the genes of two parents in offspring
increases genetic variability
– Identical or monozygotic twins
 Develop from a single zygote that splits into two
genetically identical replicas, each of which
becomes a person
– Fraternal or dizygotic twins
 Develop when two eggs are fertilized by different
sperm, creating two zygotes that are genetically
no more similar than ordinary siblings

18. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Genes and Chromosomes (3 of 4)
– Mutated gene - Permanently altered segment
of DNA
– Susceptibility genes - Make the individual
more vulnerable to specific diseases or
accelerated aging
– Longevity genes - Make the individual less
vulnerable to certain diseases and more likely
to live to an older age

19. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Genes and Chromosomes (4 of 4)
• Genotype: Person’s genetic heritage
• Phenotype: Way an individual’s genotype is
expressed in observed and measurable
characteristics

20. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Genetic Principles (1 of 3)
• Dominant-recessive genes principle
– One gene of a pair always exerts its effects,
overriding the potential influence of the other
gene
• Sex-linked genes
– When a mutated gene is carried on the X
chromosome, the result is called X-linked
inheritance

21. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Genetic Principles (2 of 3)
• Genetic imprinting
– Occurs when the expression of a gene has
different effects depending on whether the
mother or the father passed on the gene
– Chemical process prevents one member of the
gene pair from expressing itself

22. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Genetic Principles (3 of 3)
• Polygenic inheritance
– Polygenically determined - Determined by the
interaction of many different genes
– Gene-gene interaction - Studies that focus on
the interdependence of two or more genes in
influencing characteristics, behavior, diseases,
and development

23. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Some Chromosomal Abnormalities
Name Description Treatment Incidence
Down syndrome
An extra chromosome
causes mild to severe
intellectual disability
and physical
abnormalities.
Surgery, early
intervention. infant
stimulation, and
special learning
programs
1 in 1.900 births at
age 20 1 in 300 births
at age 35 1 in 30
births at age 45
Klinefelter syndrome
(XXV)
An extra X chromosome
causes Physical
abnormalities.
Hormone therapy can
be effective
1 in 1.000 male births
Fragile X syndrome
An abnormality in the X
chromosome can cause
intellectual disability.
learning disabilities. or
short attention span.
Special education.
speech and language
therapy
More common in males
than in females
Turner syndrome (X0)
A missing X
chromosome in females
can cause intellectual
disability and sexual
underdevelopment.
Hormone therapy in
childhood and puberty
1in 2.500 female births
XYY Syndrome
An extra Y chromosome
can cause above-
average height.
No special treatment
required
1 in 1,000 male births

24. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Chromosomal Abnormalities (1 of 3)
• Down Syndrome: Form of an intellectual
disability caused by the presence of an extra
copy of chromosome 21
• Klinefelter Syndrome: Disorder in which males
have an extra X chromosomes, making them
XXY instead of XY
– Have underdeveloped testes, enlarged breasts
and become tall

25. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Chromosomal Abnormalities (2 of 3)
• Fragile X Syndrome: An abnormality in the X
chromosome
– Can cause intellectual disability, learning
disability, or short attention span
• Turner Syndrome: A missing X chromosome in
females can cause intellectual disability and
sexual underdevelopment

26. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Chromosomal Abnormalities (3 of 3)
• XYY Syndrome: Male has an extra Y
chromosome
– Can cause above-average height

27. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Some Gene-Linked Abnormalities
(1 of 2)
Name Description Treatment Incidence
Cystic fibrosis
Glandular dysfunction
that interferes with
mucus production;
breathing and digestion
are hampered, resulting
In a shortened life span
Physical and oxygen
therapy. synthetic
enzymes. and
antibiotics: most
individuals live to
middle age.
1 in 2,000 births
Diabetes
Body does not produce
enough insulin, which
causes abnormal
metabolism of sugar.
Early onset can be fatal
unless treated with
Insulin.
1 in 2.500 births
Hemophilia
Delayed blood clotting
causes internal and
external bleeding.
Blood
transfusions/injections
can reduce or prevent
damage due to internal
bleeding.
1in 10,000 males
Huntington's disease
Central nervous system
deteriorates. Producing
problems in muscle
coordination and mental
deterioration.
Does not usually appear
until age 35 or older;
death likely 10 to 20
years after symptom
appear.
1in 20.000 births

28. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Some Gene-Linked Abnormalities
(2 of 2)
Name Description Treatment Incidence
Phenylketenuria (PKU)
Metabolic disorder that.
left untreated.
causesintellectual
disability and
hyperactivity.
Special diet can result in
average intelligence and
normal life span,
I in 10.000 to 1 in 20.000
births
Sickle-cell anemia
Blood disorder that limits
the body's oxygen
supply; it can cause joint
swelling. as well as heart
and kidney failure.
Penicillin, medication for
pain, antibiotics. blood
transfusions, and
hydroxyurea.
1 in 400 African American
children (lower among
other groups)
Spina bifida
Neural tube disorder that
causes brain and spine
abnormalities.
Corrective surgery at
birth. orthopedic devices.
and physical/medical
therapy.
2 in 1,000 births
Tay.Sachs disease
Deceleration of mental
and physical development
caused by an
accumulation of lipids in
the nervous system.
Medication and special
diet are used, but death
is likely by 5 years of
age.
1in 30 American Jews is a
carrier.

29. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Gene-Linked Abnormalities (1 of 4)
• Phenylketonuria (PKU)
– Genetic disorder in which an individual cannot
properly metabolize an amino acid called
phenylalanine
• Sickle-cell anemia
– Genetic disorder that affects the red blood cells

30. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Gene-Linked Abnormalities (2 of 4)
• Cystic fibrosis
– Glandular dysfunction that interferes with mucus
production
– Breathing and digestion are hampered, resulting
in a shortened life span
• Diabetes
– Body does not produce enough insulin, which
causes abnormal metabolism of sugar

31. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Gene-Linked Abnormalities (3 of 4)
• Hemophilia
– Delayed blood clotting causes internal and
external bleeding
• Huntington’s disease
– Central nervous system deteriorates, producing
problems in muscle coordination and mental
deterioration

32. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Gene-Linked Abnormalities (4 of 4)
• Spina bifida
– Neural tube disorder that causes brain and spine
abnormalities
• Tay-Sachs disease
– Deceleration of mental and physical development
caused by an accumulation of lipids in the
nervous system

33. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Dealing with Genetic Abnormalities
• Every individual carries DNA variations that
predispose the person to serious physical
disease or mental disorder
• Genes that are missing, nonfunctional, or
mutated can be associated with disorders
• Identifying genetic flaws enables medical
professions to:
– Predict an individual’s risks
– Recommend healthy practices
– Prescribe the safest and most effective drugs

34. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Reproductive Challenges and Choices
• Prenatal diagnostic tests
• Infertility and reproductive technology
• Adoption

35. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Prenatal Diagnostic Tests
• Ultrasound sonography
• Brain imaging techniques
• Chorionic villus sampling
• Amniocentesis
• Maternal blood screening
• Noninvasive prenatal diagnosis (NIPD)
• Fetal sex determination

36. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Infertility and Reproductive Technology
• Infertility - Inability to conceive a child after 12
months of regular intercourse without
contraception
• In vitro fertilization (IVF) - Eggs and sperm are
combined in a laboratory dish
– Fertilized egg is transferred into the woman’s
uterus
– Success rate of IVF depends on the mother’s age

37. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Success Rates of In Vitro Fertilization
Vary According to Woman’s Age

38. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Adoption
• Social and legal process that establishes parent-
child relationship between persons unrelated at
birth
– Increased diversity of adopted children and
adoptive parents
– Outcomes for adopted children
 Fare much better than children raised in long-term
foster care
 Children who are adopted very early are more
likely to have positive outcomes

39. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Heredity-Environment Interaction:
The Nature-Nurture Debate (1 of 2)
• Behavior genetics
• Heredity-environment correlations
• Shared and non-shared environmental
experiences
• The epigenetic view and gene × environment (g
× e) interaction
• Conclusions about heredity-environment
interaction

40. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Heredity-Environment Interaction:
The Nature-Nurture Debate (2 of 2)
• Gene × Environment (G × E) interaction:
– Interaction of:
 Specific measured variation in the DNA
 Specific measured aspect of the environment

41. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Behavior Genetics
• Discover the influence of heredity and
environment on individual differences in human
traits and development
– Twin study: Behavioral similarity of identical and
fraternal twins is compared
– Adoption study: Seek to discover whether, in
behavior and psychological characteristics,
adopted children are more like their:
 Adoptive parents, who provided a home
environment
 Biological parents, who contributed their heredity

42. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Exploring Heredity-Environment
Correlations
Heredity.
Environment
Correlation
Description Examples
Passive
Children inherit genetic
tendencies from their parents.
and parents also provide an
environment that matches their
own genetic tendencies.
Musically inclined parents usually
have musically Inclined children,
and they are likely to provide an
environment rich in music for
their children.
Evocative
The child's genetic tendencies
elicit stimulation from the
environment that supports a
particular trait. Thus genes evoke
environmental support.
A happy, outgoing child elicits
smiles and friendly responses
from others.
Active (niche-picking)
Children actively seek out 'niches
in their environment that reflect
their own interests and talents
and are thus in accord with their
genotype.
Libraries. sports fields. and a
store with musical instruments
are examples of environmental
niches children might seek Out it
they have intellectual interests in
books. talent in sports. or musical
talents. respectively.

43. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Heredity-Environment Correlations
• Passive genotype-environment correlations:
– Biological parents provide rearing environment
for the children
• Evocative genotype-environment correlations:
– Genetically influenced characteristics elicit
certain types of environments
• Active genotype-environment correlations:
– Children seek out environments that they find
compatible and stimulating

44. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Shared and Non-shared
Environmental Experiences (1 of 2)
• Shared environmental experiences:
– Siblings’ common environmental experiences
are:
 Parents’ personalities and intellectual orientation
 Family’s socioeconomic status
 Neighborhood in which they live

45. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Shared and Non-shared
Environmental Experiences (2 of 2)
• Non-shared environmental experiences:
– Child’s own unique experiences
 Within the family and outside the family
 Not shared with another sibling

46. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Epigenetic View and Gene ×
Environment (G × E) Interaction
• Epigenetic view: Development is the result of an
ongoing, bidirectional interchange between
heredity and environment

47. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Comparison of The Heredity -
Environment Correlation and
Epigenetic Views
• Heredity – Environment Correlation View
– Heredity
– Environment
• Epigenetic Views
– Heredity
– Environment

48. Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw-Hill Education.
Conclusions About Heredity-
Environment Interaction
• Relative contributions of heredity and
environment are not additive
• Complex behaviors are influenced by genes and
environments in a way that gives people a
propensity for a particular developmental
trajectory