The pedigree theory in linguistics was developed by August Schleicher middle of the 19th century. He assumed that evolve languages analogous to the evolution of biological species from original languages . Thereafter, relations and relationships between languages behave exactly as the relations of species in biology, can be represented in the form of phylogenetic trees. Starting August developed by its evolutionary considerations Schleicher including the family tree model of the Indo-European language family.
Pedigree models are hierarchical models in which developing daughter languages "genetically " related languages from parents. Thus, the Romance languages daughter languages of Latin, Latin is a daughter language of Italic, Italic a daughter language of the Indo-European. Pedigree models are used today to represent the relationships between languages and to group them.
Through language comparison can discover affinities and reconstruct parents languages partially. Thus the Indo-European proto-language has been partly reconstructed. The family tree model leads to their logical conclusion, where appropriate, to a common proto-language of all languages. This is suggested by certain phenomena of basic vocabulary and recent genetic research, it is very controversial, because each additional undeveloped older stage of the language tree contains larger uncertainties.
Aftermath of the pedigree theory
The Neogrammarians, the lasting impact on the science of language since the 70s of the 19th century, rejected the family tree theory and instead favored the wave theory of Johannes Schmidt.
Johannes Schmidt argued that can not be the Indo-European languages as simple single grouped into a family tree. He participated in mutual linguistic influences, which then occurred when language groups came into contact. Thus, there are striking similarities between the Greek and Italic, and between the Italic and the Celtic. Similar relationships exist between the Italic and Celtic ( on one hand) and the Germanic ( on the other). The Germanic in turn has specific similarities with the Slavic and the Baltic. All of these relationships can not be put into a family tree.
The Linguistic geography no longer worked for decades with the pedigree theory because this theory the constant mixing and self- influence of languages not considered.
Despite the criticism of the family tree theory some linguists still held around the turn of the century (1900) firmly to this theory.
Pedigree Similar representations
However, one must distinguish between family tree representations (in the sense of Schleicher's theory) and hierarchical tree-like formations that have nothing to do with Schleicher's theory. For example, the major German dialects often divided into Low German and High German, the latter without the creator of this " tree " have again in Central German and Upper German, Schleicher's pedigree in mind. So In these tree structures, it is not about descent and speech pitch, but the presence or absence of certain dialect features, such as the presence of traces of the Second Sound Shift.