A geologist was studying fossils she found in different layers of rock. She found many different types of fossils in layer 3 but very few in layer 2.
Which two possible explanations could she suggest for this occurrence?
A. The fossils found in layers 2, 3, and 4 have similar body parts, so they share a common ancestor.
B. Layer 4 is a different type of rock, so all of the fossils from layer 3 sank in it as new layers formed.
C. There was a mass extinction during the time period of layer 2, so very few species of organisms remained alive.
D. Fossils buried in layer 2 show the end result of a population explosion, which prevented species from evolving later on.
E. When layer 2 was forming, a natural event changed the environment and caused the organisms to move to a different location.
The two possible explanations the geologist could suggest for the occurrence of many fossils in layer 3 and very few in layer 2 are:
C. There was a mass extinction during the time period of layer 2, so very few species of organisms remained alive.
E. When layer 2 was forming, a natural event changed the environment and caused the organisms to move to a different location.
Explanation:
Option C is plausible because a mass extinction event would reduce the diversity of species and result in fewer fossils being found in layer 2.
Option E is also logical as environmental changes can lead organisms to migrate, leaving fewer fossils behind in that layer.
These explanations help understand the fossil distribution in the geological record. If you have any more questions or need further assistance, feel free to ask!