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Why Cephalopods he throw the traditional classification?

We saw in the previous article some features of the classification method or modern cladistics. And if s classification change, much to damn all systematists veterans, there are multiple reasons why it should be presented before discard our old treaties (ie an image is made no thanks!).

The anthropocentrism and teleology
Older classifications using private groups such as "invertebrates", "jawless" etc.. Now these groups have Phylogenetic no value, they do not make connections, but just to highlight the absence of attributes present in other groups. And vertebrates lack the vertebrae that man has not agnathans jaw that man a. In this sense the traditional classification of the inherited defect of anthropocentrism and teleology of "the scale of being " Leibnitz (1646-1715) who saw in nature a linear order and a gradation of species of lichens, mosses, from fish to reptiles, Men in angels ...

[The scale of beings or Scala Naturae: to follow in order: elements minerals, plants, animals, humans, and in some versions the angels ...]

Essentialism
Essentialism is the idea that essence precedes existence, ie that the species exists naturally and almost independently of individuals, and any intraspecific variation (within species) is erased and each species may represent a type specimen used for comparison: the holotype preserved in the museum. This idea culminates At the time of Linnaeus, who established the genus name and species and produces a classification of the most ambitious "Systema Naturae," or the male mallard is a different species of the female (What man field!). For a classification is natural, it should be possible without preconceptions.

Ecological and 'adaptive hopping' The first classifications
(Theophrastus, about -300 BC) are primarily utilities, such as plant has medicinal properties, such fish are eaten, etc.. By following the concepts of ecology have been added including the living environment, and despite numerous signs indicating the rapprochement between crocodiles and birds right from the nineteenth, the degree of reptiles has been retained under the pretext that the flight is birds jump adaptive enough to give him a class apart. Now the crocodiles are closer to birds than they are lizards or turtles.

[Classification traditional bubble gives a grade separated to birds because of ecological characteristics.]

Groups rendered obsolete by the usual method cladistiqu
Similarly, the group of fish has a legitimate existence of a culinary point of view is nothing but an evolutionary point of view (except for craniates without legs). It's the same for many other classical groups and known to the general public have no coherence of a phylogenetic perspective:
Here some in plants: algae, bryophytes (mosses), pteridophytes (ferns). And animals: invertebrates, fish, reptiles ...

[paraphyletic group of reptiles, and phylogenetic classification correct: lépidosauriens / archosaurs]

Ultimately the traditional classification is called eclectic everything about her legacy of old classifications and therefore their faults. And if the change is radical indeed it is still necessary because for the first time the classification is methodical transparent consistent with the principles of evolution.

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