Fire has had an important role in the evolution of the biosphere over many millions of years, and more recently has also been controlled by human beings. No other species has control of fire, although numbers of animals make opportunistic use of natural fire during foraging. In anthropology, fire is sometimes neglected but is sometimes regarded as of major importance. For Darwin it was second only to language as a human invention or acquisition. In the mid-twentieth century, fire was scarcely mentioned in anthropology texts, but accounts of its role in ritual, in foraging, and in crafts recur frequently in detailed ethnographic accounts. The time depth of human fire use remains debated, but traces of it have been found on archaeological sites up to ages of about 1.5 million years, and it becomes widespread throughout the past 300,000 years.