Evolutionary Trees

• What does an evolutionary tree show?

  How species are related and their common ancestors
• What does a branch point (node) represent in an evolutionary tree?

  A common ancestor
• Which species in an evolutionary tree are the most closely related?

  Those that share the most recent common ancestor
• Why do scientists use evolutionary trees?

  To show relationships and evolutionary history of species
• Which evidence is commonly used to build evolutionary trees?

  Fossil records and DNA analysis
• What is meant by a ‘common ancestor’?

  An ancestor shared by two or more species
• How can DNA evidence help scientists build evolutionary trees?

  By comparing genetic similarities among species
• What can evolutionary trees tell us about extinct species?

  They indicate relationships with living species
• Why are fossil records useful when building evolutionary trees?

  They provide historical evidence of species' existence
• If two species are close together on an evolutionary tree, what does this suggest about their evolutionary relationship?

  They share a more recent common ancestor