Ascomycota of their hosts. Owing to their long evolutionary history, the Ascomycota have evolved the capacity to break down almost every organic substance. Unlike most organisms, they are able to use their own enzymes to digest plant biopolymers such as cellulose or lignin. Collagen, an abundant structural protein in animals, and keratin—a protein that forms hair and nails—, can also serve as food sources. Unusual examples include "Aureobasidium pullulans", which feeds on wall paint, and the kerosene fungus "Amorphotheca resinae", which feeds on aircraft fuel (causing occasional problems for the airline industry), and may sometimes block fuel pipes. Other species can
Red hair Red hair Red hair (or ginger hair) occurs naturally in one to two percent of the human population, appearing with greater frequency (two to six percent) among people of northern or western European ancestry and lesser frequency in other populations. It is most common in individuals homozygous for a recessive allele on chromosome 16 that produces an altered version of the MC1R protein. Red hair varies in hue from a deep burgundy or bright copper (auburn) to burnt orange or red-orange to and strawberry blond. Characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the