Interest in language was always attractive. But it was not until the beginning of the 19th c. that an empirical methodology of dealing with this topic arose. The novel method was based on comparing actual languages on the base of their phonetic similarities and then working out a regularity in the differences that they exhibit. The Danish scholar Rasmus Rask first observed predictable patterns between sounds in Germanic and in other European languages. Based on these findings, Jakob Grimm formulated the first sound shift law and thus was laying the foundation for the first academic discipline in linguistics - comparative linguistics. It then was August Schleicher who, influenced by Charles Darwin, attempted to reconstruct a common ancestor of Indo-European languages and founded the evolutionary "Stammbaumtheorie".

Comparative linguists considered languages as being "organisms of nature; they have never been directed to the will of man; they rose and developed themselves according to definite laws; they grew old, and died out. They too are subject to that series of phenomena we embrace under the name of ‘life’" (Schleicher 1863).

In the 1870s the methodology of comparative linguistics finally was tightened by a group of scholars from the university of Leipzig, who called themselves Neogrammarians (Junggrammatiker). Their concept of language was no longer an organic one, but they considered language change as being based on human activity. However, according to their chief tenet, this change is guided by mechanic principles and could be described by rigid sound laws - laws without any exceptions. The Danish scholar Carl Verner thus corrected the major deficiency of Grimm's Law by introducing a further sound shift Law, since called Verner's Law. This mechanical conception reached its limit as soon as linguistics interests shifted to dialects. Neogrammarians laws were unable to explain the scope of dialect features in geographic space.

But soon after the turn of the century, under the influence of Ferdinand de Saussure (a former member of the Neogrammarians), structuralist linguistics emerged and shaped the discipline for the next half-century.

Axioms of linguistic reconstruction:

• part of the present word stock reflects words of the past
  
• the meaning of these words has not dramatically changed over time
  
• the phonological change these words underwent in their history is generally regular

Method of linguistic reconstruction:

• compare several languages that are known to be related (cognate)
  
• detect similarities in those languages which then characterize base features of their common ancestor
  
• explain systematic dissimilarities by generally valid rules
  
• build up a relative chronology of these rules; the input of the chronologically eldest rules reflects features of the ancestor language

The evolutionary language tree as well as Darwinian theory suggests a common human ancestor. Whereas the past discoveries from palaeoanthropolgy were unable to focus on a coherent model, population genetics in combination with comparative linguistics furnished a revolutionary insight into human origin. Both genealogies supporting each other, genetics was able to trace back the birth of mankind to Africa. The "Out of Africa" theory being first brought up in 1987, could be substantially supported by the leading population geneticist Luigi Luca Cavalli-Sforza when combining it to linguistic data. Furthermore it now seems probable that the spread of mankind was twofold. The bottleneck model proposes a first population which vanished about 100'000 years ago. The second repopulation then had its origins in Africa.