The earth's crust is comprised of the lithospheric plate and they are constantly in motion over the viscous layer of asthenosphere due to the generation of convection current in the mantle. It is due to the heat radiated from the interior of the earth.
These plates were once all together forming a supercontinent named Pangaea. This Pangaea got separated into Laurasia and Gondwanaland.
North America was formed from the separation of the Laurasia about 200 million years back.
This plate motion was proved by some of the evidence put forwarded by Alfred Wegener. The continental drift theory that was modified to Plate tectonic theory was able to explain the mechanism behind this plate motion.
This type of mutation mostly causes a phenomenon called frameshift mutation whereby the 3-codon sequence reading frame is shifted causing the amino acids translated, downstream of the deletion site, to be altered. This can gravely affect the function of the translated proteins and result in genetic disease.
