Salmon problem
In Indo-European studies, the salmon problem or salmon argument is an outdated argument in favour of placing the Indo-European urheimat in the Baltic region, as opposed to the Eurasian Steppe, based on the cognate etymology of the respective words for salmon in Germanic and Balto-Slavic languages. The word's wide distribution likely means it existed in its current form in a Proto-Indo-European language.
The reasoning went as follows: Since the term for Atlantic salmon in the Germanic, Baltic and Slavic languages could be derived from a common Proto-Indo-European root *laḱs-, the urheimat of the Indo-Europeans must be where both the languages and the object it describes can be found: Northern-Central Europe. The argument was first put forward by German philologist Otto Schrader in 1883. The argument was subject to continued scholarly debate throughout the late 19th and early 20th centuries, particularly in German academia.
In 1953, German indologist Paul Thieme submitted that the descendants of *laḱs- found in the Caucasus described the brown trout rather than the Atlantic salmon. American philologist George Sherman Lane concurred in a 1970 conference paper: "In my opinion, the name in question probably did refer originally not to the Salmo salar at all, but rather to the Salmo trutta caspius of the northwest Caucasus region." That lent support to the Kurgan hypothesis.
Origin
"Salmon" in early Indo-European linguistics
Since the mid 19th century, philologists began to be interested in words, which were similar in multiple Indo-European languages. They were considered to share a common origin either in Proto-Indo-European or in the younger proto language of the so-called "Litu-Slavo-Geramans" The occurrence or absence of those words was thought to provide clues for the Indo-European urheimat. Some of the numerous hypotheses about its location e.g., in Northern Europe, in the Kurgan, or in the Balkans, were based on race theory or nationalistic ideas.Comparative linguistics indicated a lack of common Indo-European vocabulary for fishes. Even a shared word for "fish" itself seemed to be absent. Both of which made an origin from Eurasian Steppe or woods, which are low on fish, seem plausible.
When it comes to salmon, dictionaries being published from the 1870s on began to compile more and more similar words for it in Germanic, Baltic, and Slavic languages. Those forms excluded the possibility of it being a loanword. In 1876, the German philologist August Fick collected,,,,,,, and. The Deutsches Wörterbuch by the Brothers Grimm added in 1877. The philologist Friedrich Kluge further added and reconstructed.
Earliest articulation of the argument
was the first to ubicate the "land of the Slavo-Germans" based on a zoogeographical argument. He argued that the terms for salmon indicated an area where salmon can be found. According to Brehms Tierleben, salmons populate the Baltic Sea, the North Sea and the eastern Arctic Ocean in Europe. Since Schrader thought this to be the origin of the Germanic people only, he did not introduce this argument in the discussion about the Indo-European urheimat.The anthropologist Karl Penka, who believed the urheimat to be in South Scandinavia, wrote about salmon in 1886, "this fish was known to Arian people," without stating, how he came to this conclusion. He expanded the salmon argument by including the lack of salmon words in it: "Salmons, which has its habitat in the Arctic Ocean and the northern part of the Atlantic, can only be found in the rivers of Russia flowing into Baltic Sea and the White Sea, but not in those that flow into the Black Sea, or the Caspian Sea. Neither does it occur in the rivers of Asia and the Mediterranean, therewith explaining the absence of corresponding forms of Proto-Indo-European *lakhasa in the Iranian and Indic languages, Greek, and Latin." Penka does not explain the origin of his reconstructed form *lakhasa.
Schrader responded in 1890: " are confined to a more limited linguistic area. The linguist Johannes Schmidt, too, used the absence of salmon words from some Indo-European languages against Penka. He argued that Penka only postulate North European terms as Indo-European to show the equivalence of Indo-European animal terms and South Swedish fauna. In 1901 Schrader took over the formulation by Penka ex negativo: "Since the fish occur in those rivers only, which flow in to the Ocean or the Baltic Sea , it becomes clear why Greeks and Romans had peculiar names for this fish."