MUNIBE (Antropología y Arqueología) Suplemento N.º 6 129-137 SAN SEBASTIAN 1988 ISSN 0027 - 3414 The basque population and ancient migrations in Europe Luca L. CAVALLI-SFORZA * KEYWORDS: Rh genes dynamics, Origin or Basques, Origin of Indoeuropean Languages, Neolithic spread in Europe, Cultural conservation. SUMMARY Basques have a unique position in Europe not only because of their language but also because of some genetic differences with their neighbors. One of the most characteristic ones is the relatively high frequency of Rh-negative genes. The simplest interpretation of the origin of Basques is that they were in their present location already in upper paleolithic and mesolithic times, when they probably occupied o wider area than now. They may represent the most direct descendants of Cro-Magnon people. Early neolithic farmers began expanding in all directions from the Middle East or Asia Minor around 9000 years ago or earlier; they mixed with local mesolithic hunter- gatherers. Those who came to Europe may have spoken Indoeuropean languages. If this is correct, the Basque language may be the only one that survived among those spoken earlier. Other non-lndoeuropean languages spoken in Europe came later from the outside. The reasons for conservation of the Basque language and culture and their interaction are discussed. THE GENETIC BACKGROUND positives will tend to increase if they are more than 50% of the population, or decrease if they are less If one looks at a tree of the genetic origin of Euro- than 50%. Obviously, the same can be said of the pean populations, one finds considerable homoge- alternative type of genes, the Rh negatives. Basques neity; but four people stray in different directions: tend to be slightly above 50% Rh negatives (fig. 1) Lapps, Icelanders, Sardinians and Basques. For the and, therefore, Rh negatives should increase while first three, we have historical or liguistic clues that Rh positives should decrease and eventually disap- help us understand al least part of the story. No such pear. Other Europeans cluster at 40% negatives or clues are available for Basques: here, on the contrary, below, and should decrease (fig. 2). How does Euro- the lingüistic evidence seems to obscure the pictu- pe remain so close to the 50% point, the most uns- re. The Basque language is described as an isolate, table of all?. with no living relatives. While there are some lin- A possible explanation is that once Europe was guists who take exception to this conclusion, as we inhabited mainly or entirely by Rh negative people, shall discuss later it remains reasonable to conclu- and later an invasion of predominantly or entirely Rh de that the Basque language is a relic. It, or langua- positive people took place. The pressure of invaders ges ancestral to it, may have once been spoken over was less important in the present day Basque area vast regions. All historical data, however, attest to than in the rest of Europe; and therefore, the mixtu- the ancient presence of the Basque language in the re of earlier inhabitants to invaders was in favor of region, so that the Basque people may have been the former. The existence of an unstable point at in their present location for a very long time. 50%-positives: 50%-negatives has helped maintain Given their linguistic isolation, it is not at all sur- the gene frequencies near the Western Pyrenees prising that Basques also show genetic peculiarities around the present value. It is of interest to note in that indicate their relative genetic isolation from their fig. 2 that the evolutionary process of gene frequen- neighbors. The existing data have been summarised cies is fairly slow, so that in the absence of any mi- and discussed by Alberto Piazza in this symposium, gration it takes 10- to 25,000 years (400-1,000 ge- and I will refer readers to his excellent paper. One nerations) to have important changes in gene of the outstanding genetic differences from other frequencies if at the start they are near 50%. populations is in the frequency of Rh genes; this is In order to discover when this «Invasion» of Euro- particularly striking as the evolutionary dynamics of pe might have happened, we must look to the ar- this gene ir rather peculiar. It is well known that Rh cheological and historical records. It is believed that Neanderthals disappeared from Europe, in particu- * Departament of Genetics. Stanford University. Stanford, Cali- lar Western Europe, between 31- to 33,000 years fornia USA. ago. (F.C. HOWELL, 1984). There is no reason to think 130 L. CAVALLI-SFORZA Figure 1. A. E. Mourant was among the first to draw the atten- tion on the high frequency of Rh negatives among Basques and the hypothesis that Basques may be protoeuropeans, least ad- mixed with later immigrants. This figure is abstracted from the geographic distribution of the Rh-negative gene d published in A.E. Mourant, A.C. Kopec, K. Domaniewska-Sobazak. The Dis- tribution of the Human Blood groups, Oxford University Press, London 1976. that modern people in Western Europe have any spe- We will assume that the entire Basque region at that cial relationship to Neanderthals. Human remains time may have been inhabited by a relatively homo- north of the Pyrenees define the Cro-Magnon type, geneous population, and will search for evidence of who is clearly modern post-Neandertheal. later migrations. Lascaux caves (dated around 15- to 17,000 BP) On the basis of our work, the most important mi- are believed to have been inhabited by Cro-Magnon- gration to Europe in the last 10,000 years was that like people. The similarity of art work north and south of Neolithic people originating in the Middle East. It of the Pyrenees supports the inference that north would be more correct to say they originated in Asia and south of the West Pyrenees the people were si- Minor, since the first appearance of the Neolithic in milar. The poverty of the fossil record south of the Europe, at the beginning of the preceramic type is Pyrenees does not offer much further clarification. in Macedonia. But undoubtedly at the time there was communication between the Middle East and Asia Minor. The theory of Neolithic expansion to Europe has been presented in some detail by Ammerman and Cavalli-Sforza (1984). The theory was engende- red by the a priori consideration that the develop- ment of food production lifted the constraints on po- pulation density existing in foraging (hunting-gathe- ring) populations. Demographic increase was gene- rated and was responsible for the geographic expan- sion of an agricultural population, which proceeded slowly to occupy available niches in vast regions, from Europe to Africa and Asia. Obviously, there were other independent agricul- tural developments in many parts of the world; but the Middle Eastern Neolithic was particularly early, rich and complex, including both plant and animal breeding. The crops domesticated in the Near East (essentially wheat and barley) proved capable of growth in a very wide area. Figure 2. Evolutionary dynamics of the Rh gene frequencies. The The evidence for this theory comes from two gene frequency of 50% Rh+ or Rh-is an unstable point; above sources. First, the archeological data (Ammerman and below it, the more common allele will eliminate the other. and Cavalli-Sforza, 1971, 1973). As is well known, Modified from L. Cavalli-Sforza and. W. Bodmer. The Genetics of Human Populations, Freeman and Co. San Francisco and New archeology cannot prove or disprove migrations; and York 1971. in fact, after the excessive «migrationist» enthu- THE BASQUE POPULATION ANO ANCIENT MIGRATIONS IN EUROPE 131 Figure 3. Computer map of the dates of first arrival of neolithic formers from their area of origin. Recalculated, from Ammermann and Cavalli-Sforza, 1984. siasm of archeologists of the thirties, there has been turned to the genetic markers of human populations. a widespread tendency to completely avoid migra- Unfortunately, no fossil data are satisfactory for our tionist explanations. The evidence, however, shows purpose. Skeletal measurements are unreliable, being quite clearly that following the introduction of agri- highly sensitive to dietetic and other environmental culture, food products typical of the Neolithic eco- conditions, and are, in any case, unavailable in suf- nomy were found at greater and greater distances ficient numbers. Common genetic markers, whose from the place of origin, the Middle East, at later and inheritance is clearly proved, cannot be detected on later dates. It has been possible to map geographi- fossil material except in very rare and insufficient ca- cally the advance of Neolithic agriculture in Europe ses. The only remaining possibility is that of exami- by plotting the times of its first arrival in well known ning living populations, on which there is a wealth archeological regions (fig. 3). Also, by plotting the of genetic data. The hypothesis will have to be made, first time of arrival to a given spot in Europe versus and tested, that there were no important changes its geographic distance from the origin, one obser- in genetic markers in the last millennia before the ves a substantially constant but slow rate of radia- present. tion of agriculture from the the Middle East (on ave- No single gene is sufficiently informative for this rage one Km per year as the crow flies). It was also analysis, and a multivariate approach was therefo- shown (see AMMERMAN and CAVALLI-SFORZA, 1984) re necessary. A new method introduced by MENOZZI, that this radial rate of advance is compatible with PIAZZA and CAVALLI-SFORZA (1978) allowed resear- the demographic increase of Neolithic populations. chers to create geographic maps of genetic paterns Therefore, the hypothesis that farmers themselves shown by European populations.