Seismic waves correspond to elastic waves that propagate on the surface and inside our planet following an earthquake.
They appear when a starting impulse sets particles in motion, which in turn will move the material to their contact before returning to their original place. The generated phenomenon can then spread over tens, hundreds, even thousands of kilometers. Note that these waves can be generated artificially in seismic studies.
Like all waves, they can be reflected or refracted when they pass from one medium to another (for example between the mantle and the Earth's core).
Vestigial structures do not have a function, yet they are homologous to functional structures in related species. They are important because they provide clues to the ancestry of the organism. Many species look similar as embryos.
<h3><em>The principle of colinearity of genes and proteins does not apply to eukaryotes because most eukaryotic genes contain introns.</em></h3><h3><em></em></h3>
