General Description and Familiar Examples
Informally, phyla can be thought of as grouping organisms based on general specialization of body plan, At the most basic level, a phylum can be defined in two ways: as a group of organisms with a certain degree of morphological or developmental similarity (the phenetic definition), or a group of organisms with a certain degree of evolutionary relatedness (the phylogenetic definition). Attempting to define a level of the Linnean hierarchy without referring to (evolutionary) relatedness is an unsatisfactory approach, but the phenetic definition is more useful when addressing questions of a morphological nature—such as how successful different body plans were.
Read more about this topic: Phylum
Famous quotes containing the words general, description, familiar and/or examples:
“There is absolutely no evidence—developmental or otherwise—to support separating twins in school as a general policy. . . . The best policy seems to be no policy at all, which means that each year, you and your children need to decide what will work best for you.”
—Pamela Patrick Novotny (20th century)
“Once a child has demonstrated his capacity for independent functioning in any area, his lapses into dependent behavior, even though temporary, make the mother feel that she is being taken advantage of....What only yesterday was a description of the child’s stage in life has become an indictment, a judgment.”
—Elaine Heffner (20th century)
“The study of tools as well as of books should have a place in the public schools. Tools, machinery, and the implements of the farm should be made familiar to every boy, and suitable industrial education should be furnished for every girl.”
—Rutherford Birchard Hayes (1822–1893)
“No rules exist, and examples are simply life-savers answering the appeals of rules making vain attempts to exist.”
—André Breton (1896–1966)