The ice retreated for the last time about 12,500 years ago.

In those first generations, as the ice retreated, they had no need to quarrel.

They are also important for understanding the direction evolution has taken since the ice retreated.

As the ice retreated, the more mobile species of life returned.

As the ice retreated, the plants and animals associated with modern Europe began to advance north.

In 1921 the ice had retreated so far that a small lake formed at its foot.

Since then the ice has retreated well away from the lakeshore.

But the mountains stood firm, and when the summer came the ice retreated for a while.

It is also likely that as the ice retreated a large lake formed in the valley.

Once the ice retreated, these were readily available for use in a variety of sizes.