There are many shreds of evidence that support the theory of plate tectonics and make it such a firmly believed idea. These pieces of evidence include fossils, glaciers, earthquakes and volcanic activity, the shape of continents, the magnetism of rocks on the seafloor, the mid-ocean ridge system, and others.
Fossils give an idea of the location of the plants and animals that once existed. Earthquakes and volcanic activity also help in determining the cause of the boundaries and rifts formed. The shape of the continents seems to be fit with one other that gives the idea that these were together and moved away from each other.
Mutations are only passed on to offspring when they occur in germ cell DNA, which are the cells that create sperm or ova. The other kind of cells, somatic cells, are the rest of the cells in the body, and mutations that occur in these cells do not get passed on to offspring.
When the two different population species interact in such a manner that it is beneficial to each other, then this form of interaction is called mutualism.
