Evolutionary Theory: Natural Selection

Evolutionary Theories

Natural Selection

• Also known as "survival of the fittest"
• Process by which individuals with favorable traits are more likely to survive and reproduce, passing those traits to their offspring
• Results in adaptation of populations to their environment
• Key components:
  • Variation in population: differences in traits among individuals
  • Heritability: traits are passed from parents to offspring
  • Differential reproduction: individuals with favorable traits reproduce more successfully

Artificial Selection

• Process by which humans intentionally select and breed individuals with desired traits
• Used in agriculture, animal breeding, and biotechnology
• Results in rapid adaptation of populations to human needs
• Examples:
  • Breeding of crops for desirable traits (e.g. disease resistance, increased yield)
  • Selection of livestock for specific characteristics (e.g. milk production, meat quality)

Inheritance of Acquired Characteristics

• Discredited theory that traits acquired through use or disuse during an individual's lifetime can be passed on to their offspring
• Also known as Lamarckism
• Not supported by scientific evidence and contradicts modern understanding of genetics and evolution

Species Adaptation

• Process by which a species becomes better suited to its environment over time
• Results from the accumulation of adaptations through natural selection
• Examples:
  • Peppered moths adapting to industrial pollution in England
  • Antibiotic resistance in bacteria

Evolutionary Development (Evo-Devo)

• Study of the evolution of developmental processes and patterns
• Examines how developmental genes and pathways have evolved across species
• Reveals conserved developmental mechanisms across diverse species
• Examples:
  • Similarities in embryonic development across vertebrates
  • Evolution of wing development in insects and vertebrates

Evolutionary Theories

Natural Selection

• Also known as "survival of the fittest"
• Process by which individuals with favorable traits are more likely to survive and reproduce, passing those traits to their offspring
• Results in adaptation of populations to their environment
• Requires three key components: variation in population, heritability, and differential reproduction
• Variation in population refers to differences in traits among individuals
• Heritability means traits are passed from parents to offspring
• Differential reproduction means individuals with favorable traits reproduce more successfully

Artificial Selection

• Process by which humans intentionally select and breed individuals with desired traits
• Used in agriculture, animal breeding, and biotechnology
• Results in rapid adaptation of populations to human needs
• Examples include breeding crops for desirable traits like disease resistance or increased yield
• Examples also include selecting livestock for specific characteristics like milk production or meat quality

Inheritance of Acquired Characteristics

• Discredited theory that traits acquired through use or disuse during an individual's lifetime can be passed on to their offspring
• Also known as Lamarckism
• Not supported by scientific evidence and contradicts modern understanding of genetics and evolution

Species Adaptation

• Process by which a species becomes better suited to its environment over time
• Results from the accumulation of adaptations through natural selection
• Examples include peppered moths adapting to industrial pollution in England
• Examples also include antibiotic resistance in bacteria

Evolutionary Development (Evo-Devo)

• Study of the evolution of developmental processes and patterns
• Examines how developmental genes and pathways have evolved across species
• Reveals conserved developmental mechanisms across diverse species
• Examples include similarities in embryonic development across vertebrates
• Examples also include evolution of wing development in insects and vertebrates

Test your knowledge of natural selection, a key component of evolutionary theory, including variation, heritability, and differential reproduction.