From soup to cells - The origin of life

• Biological evolution accounts for diversity over long periods of time.
• Through billions of years of evolution, life forms have continued to diversify in a branching pattern, from single-celled ancestors to the diversity of life on Earth today.
• Life forms of the past were in some ways very different from living forms of today, but in other ways very similar.
• Present-day species evolved from earlier species; the relatedness of organisms is the result of common ancestry.
• Life on Earth 3.8 billion years ago consisted of one-celled organisms similar to present-day bacteria.
• The fossil record provides evidence for evolution.
• There are similarities and differences among fossils and living organisms.
• Similarities among existing organisms provide evidence for evolution.
• There are similarities in the cell function of all organisms.
• All life forms use the same basic DNA building blocks.
• Scientists pose, test, and revise multiple hypotheses to explain what they observe.
• We can learn about the natural world using our senses and extensions of our senses.
• The story of the evolution of living things is always being refined as we gather more evidence.
• Our understanding of life through time is based upon multiple lines of evidence.
• Scientists use fossils (including sequences of fossils showing gradual change over time) to learn about past life.

• Nature of Science
• History of Life