Total group

Total group

.

Terminology

When referring to a systematic grouping, there is a danger of confusion between the crown and total groups, although they mean different things. For example, simply referring to a fossil as a "bird" does not tell you whether it is a familiar example derived from the last common ancestor of all living forms, or whether it is a more basal form. (By definition, all living forms fall into the crown group.)

Since all total groups correspond to a crown group, some systematists have suggested using a standardized prefix (e.g., "Pan-") to form names of total clades from the names of their corresponding crown clades. For example, "Panmammalia" (or "Pan-Mammalia" or pan-Mammalia) would be the total clade including "Mammalia" but no living non-mammals. Others have pointed out that there are already names for many total clades; for example, "Synapsida" and "Theropsida" have both been used to refer to the total mammalian clade.


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Total S.A. — Total S.A. Type Société Anonyme Traded as Euronext: FP, NYSE: …   Wikipedia

  • Group delay and phase delay — Group delay is a measure of the time delay of the amplitude envelopes of the various sinusoidal components of a signal through a device under test, and is a function of frequency for each component. Phase delay is a similar measure of the time… …   Wikipedia

  • Group decision making — (also known as collaborative decision making) is a situation faced when individuals are brought together in a group to solve problems. According to the idea of synergy, decisions made collectively tend to be more effective than decisions made by… …   Wikipedia

  • Total productive maintenance — is a new way of looking at maintenance, or conversely, a reversion to old ways but on a mass scale. In TPM the machine operator performs much, and sometimes all, of the routine maintenance tasks themselves. This automaintenance ensures… …   Wikipedia

  • Group races — are the highest standard of thoroughbred horserace in Australia. The Australian Pattern Committee recommends to the Australian Racing Board (ARB) which races shall be designated as Group races. The list of races approved by the ARB are accepted… …   Wikipedia

  • Total Cost of Ownership — (TCO, Gesamtbetriebskosten) ist ein Abrechnungsverfahren, das Verbrauchern und Unternehmen helfen soll, alle anfallenden Kosten von Investitionsgütern (wie beispielsweise Software und Hardware in der IT) abzuschätzen. Die Idee dabei ist, eine… …   Deutsch Wikipedia

  • Total Intelligence Solutions — Total Intelligence Solutions, LLC Création Février 2007 Fondateurs Erik Prince Forme juridique société à responsabilité limitée …   Wikipédia en Français

  • Group psychotherapy — is a form of psychotherapy in which one or more therapists treat a small group of clients together as a group. The term can legitimately refer to any form of psychotherapy when delivered in a group format, including Cognitive behavioural therapy… …   Wikipedia

  • Group buying — Group buying, also known as collective buying, offers products and services at significantly reduced prices on the condition that a minimum number of buyers would make the purchase. Origins of group buying can be traced to China[citation needed]… …   Wikipedia

  • Total Wine & More — was founded in 1991 by David and Robert Trone, when they opened two wine stores in Delaware. The funding for the opening of these two stores came from their previous stores named Beer World , which were located in Pennsylvania, most notably in… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”