The Earth is 4.54 billion years old; 3.8 billion years ago, the very first life form came into existence; 225 million years ago, dinosaurs came on the scene; and man took his first steps in Africa 200,000 years ago. How do we know this to be true?
Carbon-14 and other radioisotopes are used to measure the age of fossils, rocks, and other materials that make up Earth's geologic history. These techniques are reliable and valid. They provide clues into our earliest origins. And they contribute to the hundreds of lines of evidence supporting Charles Darwin's theory of evolution, which continues to stand the test of time.
To learn more, watch the video above and read the transcript below. And don't forget to leave a comment at the bottom of the page. Talk nerdy to me!