Rare speciesA rare species is a group of organisms that are very uncommon, scarce, or infrequently encountered. This designation may be applied to either a plant or animal taxon, and is distinct from the term endangered or threatened. Designation of a rare species may be made by an official body, such as a national government, state, or province. The term more commonly appears without reference to specific criteria. The International Union for Conservation of Nature does not normally make such designations, but may use the term in scientific discussion.
Stem cellIn multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell in a cell lineage. They are found in both embryonic and adult organisms, but they have slightly different properties in each. They are usually distinguished from progenitor cells, which cannot divide indefinitely, and precursor or blast cells, which are usually committed to differentiating into one cell type.
Stephen Jay GouldStephen Jay Gould (guːld; September 10, 1941 – May 20, 2002) was an American paleontologist, evolutionary biologist, and historian of science. He was one of the most influential and widely read authors of popular science of his generation. Gould spent most of his career teaching at Harvard University and working at the American Museum of Natural History in New York. In 1996, Gould was hired as the Vincent Astor Visiting research professor of biology at New York University, after which he divided his time teaching between there and Harvard.
Endangered species recovery planAn endangered species recovery plan, also known as a species recovery plan, species action plan, species conservation action, or simply recovery plan, is a document describing the current status, threats and intended methods for increasing rare and endangered species population sizes. Recovery plans act as a foundation from which to build a conservation effort to preserve animals which are under threat of extinction. More than 320 species have died out and the world is continuing a rate of 1 species becoming extinct every two years.
