Evidence for Evolution

• What are the two key ideas regarding evolution?

  General theory of evolution and natural selection
• What does the term 'evolution' refer to in a general sense?

  Species changing over time
• Who were the two biologists that contributed to the theory of evolution by natural selection?

  Charles Darwin and Alfred Russel Wallace
• What are Darwin's key observations that led to the theory of evolution by natural selection?

  • More offspring are produced than survive
  • Populations fluctuate but remain fairly constant
  • Intraspecific variation exists among individuals
  • Offspring inherit traits from parents
• What are the two key sources of evidence for the theory of evolution by natural selection?

  • Fossil evidence
  • Molecular evidence
• What do fossils represent in the context of evolution?

  Preserved remains or traces of organisms
• How do fossils help us understand evolutionary changes over time?

  They show how environments and organisms changed
• What can dating fossils and rocks allow scientists to do?

  Sequence fossil organisms from oldest to youngest
• What do fossils reveal about extinct species?

  Similarities and evolutionary relationships
• What gradual change do fossils provide evidence for?

  From simple life forms to complex Eukaryotic forms
• How can DNA be used as evidence for evolution?

  By sequencing and comparing genetic codes
• What does a similarity in nucleotide sequences indicate?

  Species are more closely related
• What can DNA sequence analysis help create?

  Phylogenetic trees showing evolutionary relationships
• How does the separation of species relate to DNA similarity?

  Less similarity indicates earlier separation