Answer:
You take any of the "signs of change in populations of organisms and their environments". For imagine, Australopithecus (early man) turning to Homo sapiens. In that way they could tell that you took this journey.
Kelp --> sea urchins ---> sea otters best represents the feeding relationships in a kelp ecosystem that has not been disturbed
by humans.
both sudden slip on a fault
Carbon dioxide is released during cellular respiration.