Final answer:
Matching mountain ranges on different continents separated by oceans provide evidence for the first development necessary for Europeans to "cross the seams of Pangaea (the oceans)."
Step-by-step explanation:
One specific piece of evidence that proves the Europeans satisfied the first of the five developments necessary to "cross the seams of Pangaea (the oceans)" is the matching mountain ranges.
Alfred Wegener proposed that the presence of matching mountain ranges on continents separated by oceans was evidence that they were once connected. For example, the Appalachian Mountains in North America align with the Caledonian Mountains in Europe. This evidence supports the idea of continental drift and the existence of a supercontinent called Pangaea.