Greater portions of the beach begin to appear during ebbing tides, until the maximum amount of beach is visible at low tide. They usually happens twice in a day. Beaches results from wave action by which waves or currents move sand or other loose sediments of which the beach is made as these particles are held in suspension.
Answer: <em>The Bottleneck Effect</em>
Explanation:
A Bottleneck effect is the sharp reduction of numbers of a population through environmental effects or human activity. It causes a loss of the genetic pool and its variety; genetic variation lowers and increases with time as random mutations occur.