Password fatigue passwords. According to a 2002 survey of British online-security consultant NTA Monitor, the typical intensive computer user has 21 accounts that require a password. Some factors causing password fatigue are: Aside from contributing to stress, password fatigue may encourage people to adopt habits that reduce the security of their protected information. For example, an account holder might use the same password for several different accounts, deliberately choose easy-to-remember passwords that are too vulnerable to cracking, or rely on written records of their passwords. Many sites, in an attempt to prevent users from choosing easy-to-guess passwords, add restrictions on password length
Most recent common ancestor all of the modern population. Due to pedigree collapse, modern individuals may still exhibit clustering, due to vastly different contributions from each of ancestral population . Most recent common ancestor In biology and genealogy, the most recent common ancestor (MRCA, also last common ancestor (LCA), or concestor) of any set of organisms is the most recent individual from which all the organisms are directly descended. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms. The MRCA of a set of individuals can sometimes be determined by referring to an established pedigree.