New Animal Phylogeny
The term " New Animal Phylogeny ", ie " new phylogeny of animals," or New phylogeny was awarded in 2000 by a French research team for a molecular biologically based family tree of multicellular animals ( Metazoa ). As early as 1995, due to molecular biological studies a new family tree for the main trunk lines of the animal kingdom, and therefore, indicated for the evolution of different animal blueprints. This " molecular" family tree was largely at odds with the previous (ie, morphologically correct) textbook knowledge to plan or macroevolution. Corresponding results were increasing in subsequent years, in the literature was initially of a "new view " is mentioned, that a "new view" of the evolution of the 35 main trunk lines of the animal kingdom. Since the turn of the millennium continued with the article by Adoutte et al. the term " New Animal Phylogeny " or shortened " New Phylogeny " by.
Key results
A molecular investigation in 1995 revealed that the brachiopods ( Brachiopoda, representatives of the ring sensor ) does not, as expected, for Using strain of new mouths ( deuterostomes ), but to the Urmündern ( Protostomia ) belong. The group of the ring sensor comes in many models blueprint evolution of critical importance, since in addition to their position in the system is extremely controversial, whether it is at all is a community of descent, and whether it is. Around very primitive or are relatively derived Animals Genetic studies underpinned all three points traditionally deemed to be improbable hypotheses: In addition to the classification in the Urmündern could not be shown that there is a community of descent at the rim sensors, and at least for the brachiopods reported the results on a relatively derived position towards. Along with some other Urmünder strains were grouped in genetic studies near the rim sensors, the new large group Lophotrochozoa was proposed. Another significant change in the traditionally advocated pedigrees arose with the advent of the Ecdysozoa hypothesis in 1997. Accordingly, the Arthropods ( Arthropoda ) show no phylogenetic proximity to the annelids, as it was assumed almost without exception before. Instead, grouped in molecular biological studies arthropods with representatives of the tube worms. Since both arthropods and the relevant representatives Aschelminthes periodically molt ( ecdysis ), Ecdysozoa ( molting animals = ) was awarded for this new community of descent of the name. The most profound changes occurred in total so within the tribe over the Urmünder. But even with the Neumündern there were several unexpected revisions, especially the reorganization of new mouths in the two major groups Ambulacraria and Chordata ( of which only the latter was generally accepted on traditional morphological basis). Another key to understanding the new major division of the animal kingdom could be developmental genetic studies, indicate the results of a many - segmented animal to be the ancestor of almost all bilaterally symmetrical animals ( Bilateria ). This hypothesis also would be in sharp contradiction to traditional reconstructions of the blueprint evolution, according to which multiple segmentation arose much later and also several times independently.
Review and acceptance of the results
Recognition of the New Animal Phylogeny depends primarily on the recognition of the results of the underlying molecular biological methods. Only the sequence of sequences of genes or non-coding DNA and RNA segments are usually studied ( recently even whole genomes ), but sometimes gene functions, especially developmentally relevant genes. Sequence similarities are evaluated using different algorithms, their usefulness is to discuss each separately. For the assessment of functional similarity is often resorted to Remaneschen homology criteria, ie criteria from the traditional morphology. On the developmental genetic level, so there is an interface to the traditional evolutionary biology, who worked with the comparison of morphological features. In general it can be said that the molecular biologically determined individual results experienced stronger or weaker depending on their subsequent approval compatibility with morphological feature comparisons. As a result of the single most controversial New Animal Phylogeny therefore the Ecdysozoa hypothesis is to be considered, as this community of descent can make in its present form no compatibility with older, morphologically justified proposals submitted. Other individual results, such as the reorganization of new mouths in Ambulacraria and Chordata, are much less controversial in this respect, because the Ambulacraria can be personalized with at least one morphological model from the 19th century agreed, and the Chordata were already an accepted community of descent. In its entirety, the pedigree of the New Animal Phylogeny with no older pedigree designs is comparable to that based on comparison of morphological characteristics. Since in some areas but there is a certain compatibility, which undergoes confirmation also drawing new morphological studies, the New Animal Phylogeny integral part of biology textbooks has become despite all return problems.