the.com/land bridge

means A strip of land connecting two landmasses, often exposed when sea levels drop, that lets animals, plants, and people migrate between them on foot.

from Straightforward compound of 'land' and 'bridge' — no hidden trick here. The concept became famous through the Bering Land Bridge (Beringia), the stretch between Siberia and Alaska exposed during the last Ice Age when glaciers locked up so much ocean water that sea levels fell, laying bare a land route humans and animals are believed to have crossed. The term itself is a 19th/20th-century geological coinage, used generally for any such exposed connection — Panama's isthmus counts too — but it was the Ice Age crossings that turned a plain descriptive phrase into shorthand for migration, survival, and the slow redrawing of maps by climate.