groups from Iberia, which contradicts previous views of them being a remnant population that trace their ancestry to Mesolithic hunter-gatherer groups," says Prof. Jakobsson. However, the results also showed that Basques, along with many other Iberian groups, carry both Neolithic farmer ancestry as well as some local mesolithic hunter-gatherer ancestry; showing that "the incoming farmers admixed with local, Iberian hunter-gather groups, a process that continued for at least 2 millennia." Rather, some 4500 years ago almost all Y-DNA heritage from Iberian admixture of Mesolithic hunter-gatherers and Neolithic farmers was replaced by the lineage of Indo-European herders from the steppe, and the Basque genetic distinctiveness is a result of centuries of low population size, genetic drift, and endogamy. In 2019, a study was published in Science in which a more fine-tuned and deep time-transect of Iberian ancient populations including the Basque were analyzed. From their abstract, it says: "and we reveal that present-day Basques are best described as a typical Iron Age population without the admixture events that later affected the rest of Iberia." This indicates Basques were isolated from admixture with outside groups since at least 1000BC or 3000 years before the present. In Iberia, these later admixture (interbreeding) events were with central European (Celtic), eastern Mediterranean and northern African populations, and genomic ancestry from them are found in all or most present-day Iberian populations, except for the Basque. Linguistics In the field of linguistics, there are two lines of investigation, both based on etymology; one on toponyms, not only in the Basque Country but also in the rest of the Iberian Peninsula and Europe, and the other on the etymology of Basque words. The aizkora controversy Some vasconists have, in the past, suggested that Basque may have several words, all related to tools, that are derived from the root word for "stone", haitz. These include:(h)aizkora "axe"(h)aitzur "hoe"(h)aitzur "shears"(h)aiztur "tongs"aizto "knife" Theories regarding the possibility of such a shared root have been put forward by Louis Lucien Bonaparte, Miguel de Unamuno, Julio Caro Baroja and others. One inference of these hypothetical and controversial etymologies was that some aspects of the Basque language had been stable and uninfluenced by other languages since the Stone Age. However, these etymologies are now doubted by mainstream vasconists. Aizkora has been identified as a loan from the Latin asciola. The root of the remaining terms – based on the Roncalese dialect, which is known for