>Problem: coastline shape is a dependent variable. Amount of water is the independent. Looking at S.America and Africa only makes a jigsaw puzzle in modern times. During the ice ages, will those continents still look like a match?
This isn't quite correct. The continental shelf maintains the general shape of the land above it. Any amount of lowering from ice ages is still going to be within the shelf break and give the same outline.
This isn't quite correct. The continental shelf maintains the general shape of the land above it. Any amount of lowering from ice ages is still going to be within the shelf break and give the same outline.