Know the history of the scientific interest in the origin of life.

• Describe the differences between the concepts of spontaneous generation and biogenesis.
• Discuss current thinking about the origin of life.
• Explain how scientists have conducted experiments that test the ideas of spontaneous generation and biogenesis.

Recognize that the nature of the Earth has changed considerably over the past 4.5 billion years.

• Describe the most probable physical conditions on early Earth and the changes thought to have happened before life could exist.
• Describe the kinds of evidence used to suggest an extraterrestrial source for life on Earth.
• Explain the experimental evidence for the origin of life from inorganic material.
• Describe different hypotheses for what the first living thing might have been like.
• Explain the chemical and physical events that must have occurred to have life originate on Earth.
• Describe the way in which organisms have caused the atmosphere of the Earth to change.

Recognize the evolutionary changes necessary to give rise to the variety of living things we see on Earth today.

• Describe the relationships among Bacteria, Archaea, and Eukarya.
• Explain the endosymbiotic theory.
• State the order and approximate times for major evolutionary events.