The earth's crust is a actually made up of supercooled magma. This crust is resting on a less solid, almost liquid like section called the Lithoshpere. The crust of the earth is divided into many parts, six large ones, and several smaller ones. These parts, call plates, slide around on the top of the lithosphere, rubbing and pushing against eachother and creating fault lines that can either create mountains or somtimes gaps in the earth. Another thing about plates is that there are occasional gaps and thin spots that are called hot spots.

 

These changes in the earth's crust change the shape and terrain of the land. In the case of the Lemur, the Island of Madagascar broke off from mainland Africa as a result of these events thereby crating a unique and isolated habitat in which the lemur evolved. The change in th terrain also effected how natural selection occured during the Lemur's long evolution. Go to the next page to see why this is.