Lake Toba, the largest lake in Southeast Asia is a remarkable volcano crater set in the middle of North Sumatera, 176 km from Medan. The lake occupies the caldera of a giant volcano that collapsed on itself after a massive eruption about a 100,00 years ago. The lake which is surrounded by a deep coastline and small valleys has a huge surface area of 1130km2. There is an island that is located in the middle of the lake that goes by the name of Samosir, is the world’s largest island within an island. In 1906, the Dutch dug a canal through the narrow passage that attaches it to the mainland. The lake’s main outflow is the Asahan river which empties into the Straits of Malacca. Due to the surrounding valleys, the climate is cool and pleasant which supports the growth of lush vegetations present in the region. In this Learning Experience, you will learn about the different factors that affect the genetic makeup of every individual in a human population. You will focus on how a natural disaster can lead to either an increase or decrease in genetic variation within a certain population.