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Chapter Outline

  • The Evolutionary Perspective

  • Genetic Foundations of Development

  • Reproductive Challenges and Choices

  • Heredity-Environment Interaction: The Nature-Nurture Debate

Natural Selection and Adaptive Behavior

  • Natural Selection: An evolutionary process favoring individuals best adapted to survive and reproduce.

  • Adaptive Behavior: Actions promoting survival due to possessed traits.

Evolutionary Psychology

Importance of Adaptation and Reproduction

  • Emphasizes adaptation and reproduction for survival.

  • Traits developed for self-protection help in survival.

  • Evolutionary Developmental Psychology: Integrates evolutionary concepts into understanding human development.

Linking Evolution to Life-Span Development

  • Benefits from evolution decrease with age.

  • Natural selection focuses on early life and reproductive viability.

  • Older adults increasingly rely on cultural resources (e.g., cognitive skills, literacy).

Criticism and Alternative Views

  • Criticisms include lack of emphasis on social/environmental factors and un-testability.

  • Alternative bidirectional view: Environmental and biological factors influence each other.

The Collaborative Gene

Human Life and Genetics

  • Human life begins as a single cell with its nucleus containing chromosomes.

  • Chromosomes: Threadlike structures made up of DNA.

  • DNA: A double-helix molecule carrying genetic information.

  • Genes: Units of hereditary information composed of DNA; responsible for cell reproduction and protein manufacture.

Genetic Mapping and Interaction

  • Human Genome Project: Mapped human genome revealing about 22,000 genes.

  • Genes interact with each other and environmental factors, influencing development and expression.

Genes and Chromosomes

Basics of Genetic Structure

  • Each body cell (except gametes) has 46 chromosomes (23 pairs).

  • Mitosis: Process of cellular reproduction.

  • Meiosis: Cell division forming gametes.

  • Zygote: Resulting single cell from fertilization merging 23 chromosomes from each parent.

Genetic Variability

  • Variability arises from gene combination in offspring.

  • Identical Twins (Monozygotic): Single zygote splits into genetically identical individuals.

  • Fraternal Twins (Dizygotic): Two separate eggs fertilized, genetically similar like regular siblings.

Important Genetic Concepts

  • Mutated Gene: Permanently altered DNA segment.

  • Susceptibility vs. Longevity Genes: Different genes affect vulnerability and lifespan.

Genotype vs. Phenotype

  • Genotype: An individual's genetic composition.

  • Phenotype: Observable traits influenced by genotype and environment.

Genetic Principles

Dominant-Recessive Genes Principle

  • One gene in a pair can override another's effects.

  • Sex-linked Genes: Mutations on the X chromosome, more commonly affecting males.

Genetic Imprinting

  • Differential effects based on the gene's origin (mother/father).

  • Can disrupt development and lead to disorders.

Polygenic Inheritance

  • Characteristics determined by multiple gene interactions alongside the environment.

Chromosomal Abnormalities

Common Conditions

  • Down Syndrome: Extra chromosome 21 leading to intellectual disability.

  • Klinefelter Syndrome (XXY): Extra X chromosome in males leading to physical abnormalities.

  • Fragile X Syndrome: Abnormality in the X chromosome affecting cognitive abilities.

Treatment and Management

  • Management strategies for conditions like Down syndrome or Klinefelter syndrome to improve quality of life.

Gene-linked Abnormalities

  • Phenylketonuria (PKU): An inability to metabolize phenylalanine.

  • Sickle-cell Anemia: Affects red blood cells' shape and ability to carry oxygen.

Reproductive Challenges and Choices

Prenatal Diagnostic Tests

  • Tests to monitor fetal development, including ultrasound and amniocentesis.

  • Risks and benefits of procedures like CVS and amniocentesis.

Infertility and Reproductive Technology

  • Infertility: Defined as inability to conceive after one year.

  • In Vitro Fertilization (IVF): Eggs and sperm combined in a lab; multiple zygotes may create health risks.

Adoption

  • Growing diversity among adopted children and parents.

  • Types include domestic and international adoptions, with varying outcomes and considerations.

Heredity-Environment Interaction

Overview of Behavior Genetics

  • Behavior Genetics: Studies hereditary and environmental influences on individual traits.

  • Twin and Adoption Studies: Useful methods for understanding genetic influences on behavior.

Types of Heredity-Environment Correlations

  • Passive, Evocative, Active: Describes how genetics interact with environment in various ways.

Conclusions on Heredity-Environment Interaction

  • The contributions of genetics and environment are interdependent and shape individual development throughout life.