Question

Sarah observed that different kinds and amounts of fossils were present in a cliff behind her house. She wondered if changes in fossil content occurred from the top to the bottom of the cliff. She marked the cliff at five positions: 5, 10, 15, 20, and 25 meters from the top. She dug out and removed 1 bucket of soil from each of the positions and determined the kind and number of fossils in each sample. What is the hypothesis?

a) Fossil content varies with depth.

b) Fossil content is constant.

c) Fossil content is unrelated to depth.

d) Fossil content decreases with depth.

Answer 1

The hypothesis Sarah is investigating is that fossil content varies with depth, which aligns with the principles of biostratigraphy and the changing environment over geological time.

Step-by-step explanation:

The hypothesis that Sarah is testing with her experiment is a) Fossil content varies with depth. By collecting and examining different fossils at various depths, Sarah can determine if there is a pattern in the types and abundance of fossils as you move deeper into the cliff's geological layers. The concept that fossil content changes with depth is supported by the knowledge that rock layers are a record of time, with the oldest layers at the bottom and the newest on top. As a result, different layers can contain different types of fossils, illustrating the history of life and environmental conditions at the time those layers were formed. Her investigation can contribute to the field of biostratigraphy, which utilizes fossil content in sedimentary layers to understand the age and characteristics of those layers.