Malus sylvestris to most European countries. It occurs in a scattered distribution pattern as single individuals or in small groups. In the past "M. sylvestris" was thought to be the most important ancestor of the cultivated apple ("M. pumila"), which has since been shown to have been originally derived from the central Asian species "M. sieversii". However another recent DNA analysis confirms that "M. sylvestris" has contributed significantly to the genome. The study found that secondary introgression from other species of the genus "Malus" has greatly shaped the genome of "M. pumila", with "M. sylvestris" being the largest secondary contributor. It also
Étienne-Louis Malus index between the surface and the interior of the glass). It was not until 1815 that Sir David Brewster was able to experiment with higher quality glasses and correctly formulate what is known as Brewster's law. This law was later explained theoretically by Augustin Fresnel, as a special case of his Fresnel equations. Malus is probably best remembered for Malus's law, giving the resultant intensity, when a polariser is placed in the path of an incident beam. His name is one of the 72 names inscribed on the Eiffel tower. Étienne-Louis Malus Étienne-Louis Malus (; ; 23 July 1775 –