Presentation on theme: "The Fossil Record Chapter 17.1. 0 The fossil record provides evidence about the history of life on Earth. It also shows how different groups of organisms,"— Presentation transcript:
The Fossil Record Chapter 17.1
0 The fossil record provides evidence about the history of life on Earth. It also shows how different groups of organisms, including species, have changed over time.
How Fossils Form 0 The formation of any fossil depends on a precise combination of conditions. 0 Most fossils form in sedimentary rock. (test question) 0 sedimentary rock sedimentary rock 0 The weight of layers of sediment gradually compresses the lower layers and, along with chemical activity, turns them into rock. 0 fossil formation fossil formation
Radioactive Dating 0 A half-life is the length of time required for half of the radioactive atoms in a sample to decay. (test question)
index fossil 0 Scientists also use index fossils to compare the relative ages of fossils. To be used as an index fossil, a species must be easily recognized and must have existed for a short period but have had a wide geographic range. (test question)
The first organisms on earth were most like todays bacteria. (test question)
Assignment 0 Take five notes from the video Earth Science: Fossils