The timeline shows the history of mapmaking.
A timeline. The timeline begins at 15,000 B C E and ends at 2000 C E. 14,000 B C E Natural objects. 200 B C E Greeks. 400 C E Middle Ages. 800 C E Arabic globe. 1100 C E Chinese printed maps. 1973 C E Digital maps.
According to the timeline, what has caused changes in mapmaking over time?