READ: Evidence for Evolution

Lesson Summary

• Fossil evidence, depicted by the skeletal fragments, demonstrates evolutionary milestones.
• Fossils and the rocks they are embedded in provide evidence of how life and environmental conditions have changed throughout Earth’s history.
• The fossils and the order in which fossils appear is called the fossil record.
• Geologists use a method called radiometric dating to determine the age of rocks and fossils in each layer of rock.
• Radiometric dating has been used to determine that the oldest known rocks on Earth are between 4-5 billion years old. The oldest fossils are between 3-4 billion years old.
• Body parts that do not serve any function are called vestigial structures.
• Vestigial structures indicate that two species have a recent common ancestor.
• The similarities between embryos suggests that animals are related and have common ancestors.
• The same biochemical building blocks – such as amino acids and nucleotides - are responsible for life in all organisms, from bacteria to plants and animals.
• DNA and RNA determines the development of all organisms.
• The similarities and differences between the genomes, the gene sequences of each species, reveal patterns of evolution.