Bell Work (9/3) Open your text book to page 40 and start reading section 1 of Chapter 2 (Ideas About Evolution.) There should be nothing out on your desk except your textbook.

Bell Work (9/3) Make sure you have your workbook. Open your text book to page 49 and start reading section 2 of Chapter 2 (Clues About Evolution.) There should be nothing out on your desk except your textbook.

How do we know adaptations happened?

Objective: Compare fossils found in sedimentary rock to determine their relative age. (SPI 0807.5.5)

Fossils and Superposition Fossil-The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock Superposition- Younger rocks lie above older rocks if the layers have not been disturbed.

Law of Superposition Please label & draw this picture.

Sedimentary Rock Sedimentary rock- formed when layers of sand, silt, clay, or mud are compacted and cemented together. Examples: limestone, sandstone, shale More fossils are found in limestone than in any other sedimentary rock.

Notice the light blue layer of rock that has been disturbed by some environmental factor (plate shifting, natural disaster). Just because the layer is not at the same depth doesn’t mean that it and the fossils it contains are not the same relative age.

Relative Age The relative age of a fossil can be determined based on its location in a layer of sedimentary rock.

Brainpop: Fossils Please get out a sheet of paper and number it 1-4.

Checks for Understanding 1. A scientist was digging for fossils along a rocky cliff. The scientist discovered trilobite fossils in rocks at different depths in the cliff. What can be determined about the fossils based on their locations? A. the diet of the fossils B. the relative age of the fossils C. the number of the fossils’ predators D. the size of the fossils’ population

2. Which layers were most likely deposited at the same time? B. 2 & 3 C. 3 & 4 D. 2 & 6

3. The scientists concluded that the fossils at these locations were approximately the same age. Which evidence supports this conclusion? A. Both locations contained a similar number of fossils. B. Both were above layers containing different types of plant fossils. C. Both contained the same type of mineral formations. D. Both were part of the same layer of sedimentary rock.

4. What type of sedimentary rock are most fossils found in?

Bonus: What prehistoric animal fossil was there a picture of on the bell work slide? Being observant is an important scientific skill.