Evidence for evolution

• What is the general belief of scientists about the origin of all life forms on Earth?

  • All life forms have evolved from single organisms.
  • These organisms existed billions of years ago.
• What types of evidence do scientists use to support the theory of evolution?

  Fossil records and genetic evidence in living species
• What is a fossil?

  A fossil is any trace of an animal or plant that lived long ago.
• Where are fossils commonly found?

  Fossils are commonly found in rocks.
• What information can fossils provide about ancient organisms?

  Fossils tell us about what the organism looked like and how long ago they existed.
• How does the depth of rock relate to the age of fossils?

  The deeper the rock, the older the fossil.
• How can fossils be arranged to provide evidence for evolution?

  • Fossils can be arranged in chronological order (oldest to newest).
  • This arrangement shows gradual changes in organisms over time.
  • Example: Fossil record of horses can illustrate the evolution of modern horses.
• What is the significance of bacteria evolving antibiotic resistance?

  It demonstrates how organisms can develop changes in their DNA that lead to new traits.
• What can mutations in bacteria lead to regarding antibiotics?

  Mutations can lead to bacteria becoming less affected by a particular antibiotic.
• Why is antibiotic resistance advantageous for bacteria?

  It allows bacteria to survive better in environments with antibiotics.
• What process leads to the passing on of antibiotic-resistant traits in bacteria?

  Natural selection leads to the resistant trait being passed on to offspring.
• How does the emergence of antibiotic-resistant bacteria provide evidence for evolution?

  It shows a change in the inherited characteristics of a population over time through natural selection.
• What is the significance of bacteria's rapid reproduction in studying evolution?

  It allows scientists to monitor the evolution of bacteria easily.
• What does the phrase "the fossil record — it rocks" imply about the evidence for evolution?

  • The fossil record provides substantial evidence for evolution.
  • It indicates that life on Earth is still evolving.
  • Evidence can be found both in fossils and through microscopic studies.
• Which statement best describes how antibiotic resistance evolves?

  The proportion of bacteria in a population killed by antibiotic treatment decreases.