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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.