variation

• What does variation refer to in a population?


  Differences in characteristics between individuals
• What are the two key factors that influence variation?

  Genetic causes and environmental causes
• How does genetic variation arise within a population?


  Through mutations in the DNA
• What is the effect of most mutations on phenotype?


  Most mutations have no effect on the phenotype
• What happens if a mutation leads to a new phenotype?


  If the new phenotype is better suited to the environment, it may lead to rapid change through natural selection
• What is evolution?


  The change in inherited characteristics of a population over time
• What is the role of natural selection in evolution?


  It allows individuals with advantageous traits to survive and reproduce
• How does natural selection lead to a change in the population over time?


  Advantageous traits become more common in the population
• From what are all species believed to have evolved?


  Simple life forms that developed more than 3 billion years ago
• What is speciation?


  The formation of two new species when populations can no longer interbreed
• What indicates that two populations have formed two new species?


  They can no longer interbreed to produce fertile offspring
• How do genetic and environmental factors interact to influence variation?


  • Genetic causes: Variation due to inherited genes
  • Environmental causes: Variation due to conditions like diet and climate
  • Most variations arise from a combination of both factors
• What are the key concepts of the theory of evolution by natural selection?


  • Natural selection favors individuals with advantageous traits
  • Over time, these traits become more common in the population
  • All species evolved from simple life forms over 3 billion years ago
• What are the key opportunities for skills development in this topic?

  • Explaining the interaction of genetic and environmental factors
  • Understanding natural selection's role in evolution and speciation