Evolutionary capacitanceEvolutionary capacitance is the storage and release of variation, just as electric capacitors store and release charge. Living systems are robust to mutations. This means that living systems accumulate genetic variation without the variation having a phenotypic effect. But when the system is disturbed (perhaps by stress), robustness breaks down, and the variation has phenotypic effects and is subject to the full force of natural selection. An evolutionary capacitor is a molecular switch mechanism that can "toggle" genetic variation between hidden and revealed states.
Ash (analytical chemistry)In analytical chemistry, ashing or ash content determination is the process of mineralization for preconcentration of trace substances prior to a chemical analysis, such as chromatography, or optical analysis, such as spectroscopy. The ash content of a sample is a measure of the amount of inorganic noncombustible material it contains. The residues after a sample is completely burnt - in contrast to the ash remaining after incomplete combustion - typically consist of oxides of the inorganic elements present in the original sample.
MaghrebThe Maghreb (ˈmʌɡrəb; al-Maghrib), also known as the Arab Maghreb (المغرب العربي) and Northwest Africa, is the western part of the Arab world. The region comprises western and central North Africa, including Algeria, Libya, Mauritania (also considered part of West Africa), Morocco, and Tunisia. The Maghreb also includes the disputed territory of Western Sahara (controlled mostly by Morocco and partly by the Sahrawi Arab Democratic Republic) and the Spanish cities Ceuta and Melilla.
OakAn oak is a tree or shrub in the genus Quercus (ˈkwɜːrkəs; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably Lithocarpus (stone oaks), as well as in those of unrelated species such as Grevillea robusta (silky oaks) and the Casuarinaceae (she-oaks). The genus Quercus is native to the Northern Hemisphere and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas, Asia, Europe, and North Africa.