Water is the dominant force in the Everglades, shaping the land, vegetation, and animal life in South Florida. Starting at the last glacial maximum, 21,000 years ago, continental ice sheets retreated and sea levels rose. This submerged portions of the Florida peninsula and caused the water table to rise. Fresh water saturated the limestone that underlies the Everglades, eroding some of it away, and created springs and sinkholes. The abundance of fresh water allowed new vegetation to take root, and formed convective thunderstorms over the land through evaporation.[36][37]