maintained by grazing. In early 2006, the third- and fourth-generation animals produced by the project were considered looking much like the depictions and preserved specimens of the quagga. This type of selective breeding is called breeding back. The practice is controversial, since the resulting zebras will resemble the quaggas only in external appearance, but will be genetically different. The technology to use recovered DNA for cloning has not yet been developed. See also Holocene extinction Lists of extinct animals References External links Zebras Extinct mammals of Africa Mammal extinctions since 1500 Mammals of South Africa Species endangered by use as food Species made extinct by human activities Mammals described in 1785 Subspecies Taxa named by Pieter Boddaert