• DOI:10.1086/394568
• Corpus ID: 84634277

The Kingdoms of Organisms

@article{Copeland1938TheKO,
  title={The Kingdoms of Organisms},
  author={Herbert Faulkner Copeland},
  journal={The Quarterly Review of Biology},
  year={1938},
  volume={13},
  pages={383 - 420}
}

• H. F. Copeland
• Published 1 December 1938
• Geology
• The Quarterly Review of Biology

Sacramento Junior College T HIS paper proposes the recognition of certain groups of living creatures as kingdoms in addition to the two which are conventionally recognized. Revision of the primary classification of organisms is a taxonomic operation, governed by taxonomic principles; it differs from revision of a family or genus only in wider scope. Because of the human need of an arrangement of organisms which will express as fully as possible existing knowledge and opinion concerning them, all groups are always subject to revision. Revision is required whenever the currently accepted groups can be replaced by more nearly natural groups. In practice, a group is held to be natural if each of its members is bound to the others by the whole range of its characters, of which some may be common to the whole group, while those in which there is variation exhibit intergradation. Assuming evolution to be a fact, this continuity of character is interpreted as representing, and the quality of naturalness is regarded as identical with, the possession of a common ancestor. Very many of the accepted taxonomic groups are, so far as knowledge can be positive, positively natural. Others are less positively natural; there is an unbroken transition to acknowledged artificialities, groups maintained for the disposition of races too poorly known as yet to permit of their disposition according to relationship. The ancestor of a particular group, unless it was the original form of life, must also have had ancestors; and from these, if we go back far enough, we will always find collateral descendants. Accordingly, the limits of each natural group are indefinite at one or more points where there are transitions to related groups. We can give broader limits to any group by taking into account a more distant common ancestor, or narrower limits by considering a more recent one. The limits assigned to a particular group, one which is named, assigned to a definite taxonomic category, and defined by description, are always artificial, arbitrary, decided by convenience. Convenience at this point means something subordinate to the overriding convenience or necessity of recog-