Variation and evolution

• What can lead to huge variation between individuals?

  Differences in genes and environment
• What is the process called that can lead to the evolution of new species?

  Natural selection
• What term describes the differences among individuals in a population?

  Variation
• What does a phenotype describe?

  Observable characteristics of an individual
• What two factors interact to determine a phenotype?

  Genes and environment
• What do genes code for?

  Proteins
• What is a genome?

  All of your genes combined
• Why do identical twins look different sometimes?

  Due to environmental factors
• How can environmental factors affect identical twins?

  Different diets or sun exposure can alter traits
• What influences most of our traits?

  Interaction of genes and environmental factors
• What causes genetic variation?

  Mutations
• What is a mutation?

  A change in the DNA code
• What is the effect of most mutations on phenotypes?

  They usually have no effect
• What happens when mutations do change proteins?

  The phenotype may change slightly
• What are beneficial mutations?

  Mutations that improve survival chances
• Who proposed the idea of survival of the fittest?

  Charles Darwin
• What did Darwin observe about traits in populations?

  Useful traits were passed on more
• What does natural selection describe?

  Fittest individuals are selected to survive
• What is evolution according to Darwin?

  Inheritance of traits leads to species changes
• From what do all current species evolve?

  Different species in the past
• What does the theory of evolution imply about all living species?

  They evolved from simple life forms
• How has Darwin's theory been proven over time?

  Through antibiotic resistance and fossil records
• What occurs through natural selection over time?

  Genetic changes give rise to suited phenotypes
• What happens when two populations become so different?

  They can no longer interbreed
• What signifies the formation of a new species?

  Inability to produce fertile offspring
• What are the key points of natural selection and evolution?

  • Variation exists in populations
  • Natural selection favors beneficial traits
  • Evolution leads to changes in species over generations
  • New species can form when populations diverge
• What evidence supports Darwin's theory of evolution?

  • Development of antibiotic resistance in bacteria
  • Fossil records showing gradual changes
  • Genetic studies confirming common ancestry
• What are the implications of evolution by natural selection?

  • All living species share a common ancestor
  • Species adapt to their environments over time
  • Genetic diversity is crucial for survival