The Galapagos Islands is an archipelago of 13 major and 100 smaller islands. It is located in the Pacific ocean near the west coast of Venezuela. In old Spanish galapagos meant tortoise. These islands affected Darwin's thoughts about evolution of species. In 1835 he spent five weeks on the islands. While on island he discovered species of <em>finches and observed that species of finches varied from island to island</em>. It helped him to elaborate his ideas about natural selection and examine the evolutionary changes of the finches.
Mechanical weathering breaks rocks into smaller pieces without changing their composition. Ice wedging and abrasion are two important processes of mechanical weathering. Chemical weathering breaks down rocks by forming new minerals that are stable at the Earth's surface.
Deposition is the laying down or settling of eroded material. Sediment deposited in water typically forms layers called beds.
Electricity is used to move DNA molecule fragments through the agarose gel. This technique has lots of applications.
More recently, aerial photographs have often been taken from fixed-wing aircraft and today can even be taken from unmanned aerial vehicles (also knowns as drones).
