The layers above would be not as old and the layers below would be the older layers.
Exoskeleton
Exoskeleton is a evolutionary innovation. This is operated by muscles attached to it and acts as an armor. Other than support this is an adaptive mechanism to provide protection against predators. In vertebrates, it is considered as the dermal bone that developed via membranous ossification. Fishes retained their exoskeleton in the form of their scales. However, in some organisms terrestrial evolution allows the loss of exoskeleton and formed a more mobile endoskeleton,
Answer:
Inertia- the tendency of an object to resist a change in velocity
Explanation:
Say a car was going at 65 MPH, but suddenly stopped. For all of the people in that car, their bodies would keep moving forward at 65 MPH until stopped by an equal force (say, the thing right in front of each person) The seatbelt is there to protect you from your own inertia.
Proteins, carbohydrates, nucleic acids, and lipids