In the 19th century, linguists came up with the idea that nearly all modern European languages are descended from an ancestor language called Proto-Indo-European (PIE), which they proposed was spoken prior to about 3500 BCE. The idea of PIE was to play a powerful role in recent world history.
Inspired perhaps by the Biblical notion of an original language of the Garden of Eden, linguists labored to reconstruct the vocabulary and grammar of PIE, and for this they used theories related to sound shifts and certain ideas about the antiquity of languages. A lot of “analysis” went into finding the original homeland of PIE, and it was usually located in Ukraine or Southern Russia.
A linguist named August Schleicher even created a fable called The Sheep and the Horses in imagined PIE to amuse himself and future generations of students.
The philologist Arthur de Gobineau argued that the languages of Europe were closest to PIE, marking the Europeans for superior character and access to scientific knowledge. From there the special role ordained for the Europeans in maintaining colonies in Asia, Africa and the Americas was not a big jump. British historians saw the British Empire as historic fulfillment of a divine mission.
Trying to outdo the English and the French who had shut them out of the closed markets of their colonies, the Nazis in Germany declared that they were the master race, inhabiting a region not far from the homeland of the PIE. Academics with minds marinated in 19th century racism continue to spin the most fanciful derivations of PIE words.
All right, it is sad history. Shall we say it was a good idea that was put to evil ends by unworthy people? That doesn’t make the theory wrong, or give us license to announce the death of PIE.
PIE as generally understood considered the original homeland to be somewhere in Europe, north of the Caucasus, and it assumes a certain time span, considerably before the time for which we have records.
The first substantive records in any IE language are in Sanskrit. The earliest period from which we have these records is conservatively taken to be 2000 BCE and in fact could be half a millennium older if we consider the astronomical evidence within the Vedic books, which has become properly understood only in the recent decades.
Furthermore, the conservative date for the drying of the Sarasvati River, the preeminent river of the Ṛgveda, extolled as going from the mountain to the sea (RV 7.95.2), is seen as 2000 BCE. There is much additional evidence related to the continuity in the arts and cuture and the remembered tradition. The idea of PIE requires antiquity much greater than that of the Vedas.
New research calls into question both the elements on which the idea of PIE stands. In one recently reported research, bones of 45 ancient humans from the Caucasus region, from a period some of which are as late as 2500 BCE to 1200 BCE, were analyzed for their DNA. The research showed that these ancient people moved predominantly from the south to the north. This indicates that the IE languages perhaps arose south of the Caucasus Mountains, spreading to other parts of Europe as people migrated north from this region.
If PIE lay south of the Caucasus and Indo-European (IE) languages in Europe are much younger than presumed before (and as late as 2000 BCE) then there is no period that can be assigned to a hypothesized parent language, and PIE is dead.
More on PIE and Archaeology
If the periods necessary for the evolution of modern IE languages from PIE are no longer supported by the evidence, and if there was no PIE, we must accept some other process, perhaps an amalgam of diffusion with movement of people as the lesser vehicle, that led to the spread of IE languages.
PIE is based on analogies and models from the hard sciences that do not apply to language. Contrary to what is assumed in PIE, the scientific study of genetics (a field that arose after the naïve genetic notions of philology had become frozen) tells us that diversity arises out of the complex relationship between the genes of a large host population and not from a family of uniform characteristics.
The diversity of the languages around 4000 or 5000 BCE, the period when the PIE speakers are supposed to have lived in their homeland, is likely to have been much greater than the subsequent period, just as was seen in America when the Europeans arrived.
The identification of the PIE homeland was based on a selective use of words of the supposed common vocabulary of the IE languages. It was suggested that since there are common words for many blood relatives, and not the same number for in-laws, therefore in the original society the relationship with the in-laws was not close. Going by this method, the people in the homeland knew butter but not milk, and snow and feet but not rain and hands.
This is not all. A certain chronology was assigned to the oral texts, and then certain changes were postulated that agreed with the assumed model. In circular reasoning, these changes were now taken as the proof that the model was correct. The logic was somewhat like a fisherman using a net of a certain cross-wire size and then arriving at the inference that the lake has no fish below that size.
An attempt to connect archaeology to PIE was made by Marija Gimbutas in her kurgan hypothesis. She traced the language back to the Yamnaya people, herders from the southern grasslands of modern-day Ukraine, who domesticated the horse.
But new research suggests that around 2500 BCE, Yamnaya genes replaced about seventy-five percent of the existing human gene pool in Europe. This is very late, and it leaves no room for the development of a PIE within Europe.
Evidence from India
The evidence from India provides a picture quite consistent with the facts that have emerged.
The earliest geography known to the Ṛgveda is the region of the Seven Rivers in Northwest India, but this does not rule out the presence of related languages beyond the borders of India. Our knowledge of Vedic astronomy shows that the earliest remembered period in the hymns comes from late 4th millennium or early 3rd millennium BCE, which is prior to the supposed entry of the IE languages into Europe.
Later books, such as the Aitareya Brāhmaṇa, which belong to the 2nd millennium BCE, speak of the expansion of the Vedic religion into regions called Uttara Kuru and Uttara Madra beyond the Himalayas to the northwest. Aitareya Br. 8.14 says Uttara Kuru had Vedic consecration for their kings. Ptolemy knows of these regions as Ottorokorrha and describes them lying between the Aral and the Caspian Seas and Megasthenes and Strabo are emphatic that the Uttarakuruvah [Hyperboreans] are connected with the Indians.
The connections between the Vedic and the Slavic people could have emerged through the agency of the mediating Vedic states of Uttara Kuru and Uttara Madra, and from them certain ideas were passed further on to the languages of north and south Europe.
There is also evidence of the interaction between the Vedic people and West Asians through the Mitanni Empire, which, in turn, explains many commonalities between the Sanskritic and the Semitic worlds.
A reasonable way to understand the spread of IE languages is through the process of diffusion together with some movement of people in a manner that is not so different from the spread of Indian culture in Southeast Asia.
PIE was based on many fanciful assumptions. From a logical point of view, its proponents forgot that it is not enough to show that a reconstructed (and imagined) PIE, A*, leads to languages B, C, and D, but that the derivation excludes all other reconstructed languages. One must be able to exclude reconstructions such as L*=> C => B => D or M* => D => C => B and any number of permuations thereof.
This simply cannot be done, and so the PIE reconstruction is simply worthless, and just one of any number of similar reconstructions one can develop.
In retrospect, we cannot say that the labors of the linguists who created it were no worse than that of the scholiasts in the Middle Ages who determined how many angels can be accommodated on the tip of a pin. Because of the wars and violence that PIE has engendered, it should be compared to the similarly sloppy reasoning that led Europe, over the course of a century and a half, to try 80,000 people for witchcraft, half of whom were executed, and often burned alive.