Speciation (T)

• Who independently proposed the theory of evolution by natural selection alongside Charles Darwin?

  Alfred Russel Wallace
• What was the main focus of Alfred Russel Wallace's studies in relation to animals?

  He studied warning coloration in animals.
• In what year did Darwin and Wallace jointly publish their findings on evolution?

  1858
• What is the significance of the geographical barrier in the process of speciation?

  It separates populations and prevents interbreeding.
• What are the stages of speciation as described in the context of snails?

  1. Initial population can interbreed.
  2. A geographical barrier (e.g., a river) separates the population.
  3. No interbreeding occurs between the separated groups.
  4. Natural selection favors different alleles in each group.
  5. Mutations cannot spread between the groups.
  6. Over generations, the populations change.
  7. If they can mix again, they can no longer reproduce fertile offspring, becoming different species.
• How did Wallace's observations contribute to our understanding of speciation?

  He highlighted the role of geographical barriers in speciation.
• What is the title of Darwin's publication that presented natural selection to a wider audience?

  On the Origin of Species
• Why is it important for students to learn about the stages of speciation?

  It helps explain how new species form, a common exam topic.