The Neolithic Advance and the Success of Genetic Y-DNA Marker R1b
When in 2008 I first got the idea that the male genes most commonly assocated with “violent Indo-European migrations” were in fact most of all distributed by peaceful genetic principes and the mechanism of a mutational wave front, my requests to the scientific community to work this out in a comprehensive mathematical model that included all relevant subclades of haplogroup R, was received with haughty snubbing. This year there is an explosion of publications centered around this theme, and a link between the genetic subclade R1b and the Neolithic wave of advance is now accepted as the majority position. Even more promising: also the limits of this approach are now being discussed, resulting in the first outlines of contrary movements west to east that formerly were considered outrageous and a heresy against the dogma of “ex oriente lux”.
Of all paternal lineages that have been identified in Europe by studying the distinct Y-chromosomal haplogroups, probably the group commonly referred to as R1b has caused most confusion. The occurrence at high frequencies in western Europe and the estimated 110 million of European males currently sharing this R1b lineage, caused the initial consensus to be in favour of a very old, even paleolithic presence. This did not prevent early speculation about more recent connotations, but even the the most hilarious novel “genealogic” age estimates couldn’t reconcile the genetic closeness to its eastern sisterclade R1a – prematurely dubbed the prime “indo-european” marker already in the earliest Y-chromosome publications – with the recent spread of the Indo-European languages: According to the linguists’ consensus this group of languages could never have originated much more than 5000 years ago. The predominance of R1a from Poland to India and R2 from Kurdistan to Bangladesh vaguely suggested some cultural link, but the high genetic age and pretty sharp delimitations between the different genetic groups – including R1b – was hard to reconcile with contemporary archeological evidence.
The human species appears to be quite homogeneous genetically and this applies especially to the male Y-chromosome. The importance of Y-DNA expression is typically played down, and only a few investigations indicate some vague link between Y-DNA haplogroups and a direct genetic advantage. So far, the results tend to be hard to evaluate. Eg. S. Shoaib Shah et al., 2008:
effect-size comparisons allowed us to detect an association of the haplogroups R2 [...] and R1a1 [...] with lower self-reported aggression mean scores in this population
In another study, the European Society of Cardiology links male Y chromosome variants with the risk of heart disease, indicating that the overwhelming Britsh R1b majority population must be better equiped against coronary diseases than the “Native European” haplogroup I population.
All together, low aggression and genetic protection against age- or lifestyle related diseases can hardly be taken serious as an evolutionary advantage for an “Indo-European” society traditionally imagined as violent and dominated by young warriors on horseback. So even if true that the male carriers of haplogroup R had a genetic advantage that facilitated its success, for sure this advantage – just like with the successful gene for lactose persistency – must have been accompanied by a new cultural level.
Like most majority haplogroups in the world, R1b (or more especifically for Europe: subclade R1b1b2) is now incorporated in the select body of major haplogroups that has been attributed a Neolithic age.
Balareque et al. proposed a relation between the gradual advance of Neolithic farming land and the introduction of male DNA marker Haplogroup R1b. The increased momentum of this change at greater distances from the center resulted in higher frequencies in the west, while diversity (not shown) was assumed to follow a star-structure. Variance was interpreted as an indication of age.
In their 2010 article Balaresque et al. gave the Neolithic kick-off:
…our evidence supports a different interpretation: that R1b1b2 was carried as a rapidly expanding lineage from the Near East via Anatolia to the western fringe of Europe during the Neolithic.
Their dating was in the Neolithic range, having eastern R1b slightly older than western R1b, but their prime argument was the star-like structure they detected in the STR values:
The two hypotheses also make different predictions for the number of sources of diversity within hg R1b1b2: under the postglacial recolonization model, we expect multiple sources, whereas under the Neolithic expansion model, we expect only one.We can test this by examining the phylogenetic relationships among microsatellite haplotypes. A reduced median network of 859 haplotypes (Figure 3) shows a simple star-like structure indicative of expansion from one source [...]. This pattern seems incompatible with recolonization from differentiated refugial populations [...]. The core of the network also contains haplotypes from Turkey (Anatolia), which is compatible with a subpopulation from this region acting as a source for the westwards-expanding lineage.
Almost inmediately this star-like features (and the recent dating) were contested by Morelli et al., who detected a rather bipolar structure due to the inclusion of a single marker (DYSA7.2 or DYS461), BTW to the effect that European R1b was again interpreted as pre-Neolithic:
“The Sardinian haplotypes belong to the Atlantic Modal Haplotype variability, with an interesting internal differentiation shown by the completely Sardinian branch off-shoot (figure 2A). In contrast, the majority of Anatolian samples belong to the DYS39312/DYSA7.2-11 subtype. Interestingly, the bridge between the two main forms, is represented by the intermediate step of a haplotype common in the Balkan region, DYS393-13/DYSA7.2-11.”
The subsequent “Neolithic R1b” article of Myres et al. (2010) conforms to the notion of an important dichotomy dividing R1b in an eastern and western grouping, this time based on SNP M412. This SNP based dichtomy is more or less equivalent to the much older ht15 denomination against ht35 (~ M412-) elsewhere. The investigators disclose a minor indication that R1b (cq. M412-/ht35) might have been present in SE Europe already before the Neolithic:
Although this frequency pattern closely approximates the spread of the Linearbandkeramik (LBK), Neolithic culture, an advent leading to a number of pre-historic cultural developments during the past 10 thousand years, more complex pre-Neolithic scenarios remain possible for the L23(xM412) components in Southeast Europe and elsewhere.”
However, Myres et al. gives a different twist to the bipolarity and make a distinction between early and late Neolithic LBK-related expansions:
Archeologically, there are two attested phases regarding the geographic spread of the Linearbandkeramik (LBK). The first phase extended to the upper Danube river near Munich. The second phase extended further to the Paris basin. Furthermore, there is evidence of several post-LBK Neolithic expansions, ca 6000 years BP from the Paris basin region toward Northern Italy, Southern France and Iberia, characterized by the Chasseen horizon, as well as to England.”
These dates are well within the range of the earliest Neolithic activity in Britain and Ireland (Sheridan, 2007):
[...] Neolithic activity, reliably dated to between c.3950/3900 and 3700 cal BC in northern Britain (especially Scotland), that is associated with the use of pottery in the ‘Carinated Bowl’ ceramic tradition [...]. The distribution of this type of pottery extends far beyond the area under review, to encompass much of Britain and much of Ireland. The Carinated Bowl-associated Neolithic is one of at least three distinct strands of the earliest Neolithic activity in Britain and Ireland, the others being i) a strand linking north-west France (probably Normandy) with southwest England during the first quarter of the fourth millennium cal BC [...] and ii) a Breton strand, which is found along the Atlantic/Irish Sea façade and seems to have appeared marginally earlier than the Carinated Bowl tradition, between c. 4200 and 3900 cal BC.
[...] it is clear that the end of the fifth millennium cal BC was a time of agricultural expansion after a period of ‘stasis’, when huntergatherer communities in the Netherlands finally switched to farming (Louwe Kooijmans 2005)—most likely thanks to influences from the south-west— and when farming groups, ultimately deriving from the north-east of the Paris Basin, are suspected to have moved north and eastwards
Balaresque et al. already predicted some exceptions to the star-structure, but these rather applied to the linear expansion of hg E-81 along the mediterranean coast, and less to the semi-circular wave front implied by the continental Neolithic wave of advance in Europe:
Successive founder effects at the edge of the expansion wave can lead to a reduction in microsatellite diversity, even as the lineage increases in frequency.
The innovations in the Near East also spread along the southern shore of the Mediterranean, reflected in the expansion of hg E1b1b1b (E-M81), which increases in frequency and reduces in diversity from east to west.
Only Myres comes up with a possible explanation of the bipolarity, in their results implied by the existence of a M412 hemisphere in western Europe:
Our high resolution SNP genotype results show that the majority of Central and Western European haplogroups relate to common M412 founders whose sub-clades display phylogeographic and temporal patterns consistent with allele surfing at the periphery of expansions.
Where did this M412 surfing start, that must have initiated the European dichotomy for haplogroup R1b in a western and southeastern group? The alternative brought forward by Myres et al. would possibly imply that M412 was already in Central Europe (or maybe even further!) at the time that the Early Neolithic arrived there:
Our estimate of 8870 +/- 1708 years BP, based on 757 M412 chromosomes, suggests that the M412 lineage evolved in Europe soon after the arrival of a L23* ancestor. [...] Notable are the equivalent expansion times for all S116 (n=481), Td 8630 +/- 1529 years BP and U106 (n=239), Td 8742 +/- 1551 years BP-related lineages. (Myres et al. – 2010)
Or could it be rather congruent and contemporary to the Late Neolithic expansion?
As far the distribution of R1b is concerned, the Early Neolithic was limited basically to Central and SE Europe. Here is a gap of 1500 km where early occurrence of M412 is problematic because of low frequency, variance and availability of almost all key M412 subclades. This is why the earliest advance of M412+ correlates best to the late Neolithic expansions, that – to the exception of Iberia – covers most of western Europe.
It is a pity the Myres article does not arrive at a deeper analysis here and only seems to clear the field for an answer in the pre-Neolithic, not unlike Morelli et al. The dates of Myres et al. should need a correction to make the distribution of M412 (partly) congruent to the late-neolithic expansion, that started about 4000 BC in western Europe.
How come genetic dating is still causing so much trouble and contradictory results? Contrary to the inflated ages typically in vogue among population genetists (commonly considered 3x too high by genealogic opponents), there is increasing support for genealogic dates that on the other hand are probably sometimes up to 3x too low. Nowadays everybody can order their own marker sets of 12, 37, 67 or more STR for trying to make sense out of a multitude of dating methods, often for genalogic reasons or just amateur interest. Mathematicians, capitalizing on the delight of amateur genealogists, often managed to reverse the paleolithic dates into historical dates, but most of the time the private dating results are achieved without genome-level insight or calibration, even without any sense of historical or archeological context whatsoever. Only this year the dating methods and correlation models that concern the paternal R1b haplogroup lineages are hard on their way to become valuable tools to untangle the European prehistory. Microsatellite diversity at picked locations at the Y-chromosome are considered, where short base-pair sequences (STR) are tandemly repeated by a semi-characteristic value. Unlike the rare base-pair alterations (SNP) that define the different Y-chromosome haplogroups, this microsatellite diversity is commonly interpreted as “datable” for being the result of spontaneous mutation processes from within, that albeit unpredictable are thought to occur at a certain “biological” rate.
More generally, knowledge of the rates and processes of mutation at different classes of marker is fundamental to evolutionary interpretations of diversity data [...]. In this broader context, studies on the Y chromosome are of particular interest because the mutations observed here are the result of exclusively intra-allelic processes. (Jobling et al., 2004)
The strict assumption with STR-age calculations is predictability of spontaneous mutations, to the exclusion of external factors that make mutations inpredictable. The mutation rate at each STR locus may vary significantly, but by taking several loci together the rates could be averaged. Spontaneous mutations are the result of normal DNA metabolism, while induced mutations are the result of agents that are not part of normal DNA metabolism. For instance, agents that cause induced mutations are radiation of various types, highly reactive metabolic byproducts that are produced within a cell, toxins that enter the body from direct contact, inhalation, eating or drinking. Take away all this “open system” factors, and you’ll get the “predictability” you need for making TMRCA calculations.
Some haplotypes are very “average”, while others are very different. How such differences could serve any purpose at all for estimating an age? All haplotypes have the same age counted from any common SNP mutation, so the assumption that mutational processes affect most people more or less in the same way does not hold. Other mechanisms must be at work that especially concern marked outliers.
It should be clear that no assumptions to the effect of spontaneous mutations exist that relate to SNP’s, thus making all speculations about a purported SNP mutation rate much more than precarious, and comparative at most. Moreover, it can’t be excluded that induced mutations causing new SNP’s also excite the STR to new values that may be instable or just very unlikely – thus creating a STR-SNP correlation that does not reflect the STR age, being based on spontaneous mutations.
The genealogic dating issue appears to be almost resolved since the investigation of Zhivotovsky et al., 2006:
Mutation rates observed in pedigree and family studies [...] are, on average, 2.1–2.6 x 10–3 per generation. By studying short tandem repeat (STR, or microsatellite) variation within haplogroups C2 and H1 in populations with known short-term foundation events (Bulgarian Gypsy and New Zealand Maori) and comparing autosomal and Y-chromosomal microsatellite variation, Zhivotovsky et al. (2004) suggested that an effective mutation rate of 0.69 x 10–3 per 25 years could serve as the rate of evolution at Y-chromosomal STR loci (see further discussion in Di Giacomo et al. 2004; Zhivotovsky and Underhill 2005). A mechanism that might explain this 3- to 4-fold discrepancy is that [...]“
Zhivotovsky sought the explanation of his reduced mutation rates in effective population sizes, that should be assumed much lower than the normal population size. however, on haplotype level there was also the issue of outliers. Myres et al. (2010):
The ages of various haplogroups in populations were estimated using the methodology described by Zhivotovsky et al., modified according to Sengupta et al, using the evolutionary effective mutation rate of 6.9 * 10 -4 per 25 years. The accuracy and appropriateness of this mutation rate has been independently confirmed in several deep-rooted pedigrees of the Hutterites. Important caveats to consider include the fact that coalescent times (Td) is sensitive to authentic rare outlier alleles and that multiple founders during population formation will inflate the age estimate of the event.
Most likely those “outliers” are caused by induced mutations, that thus would mess up the observed rates. The matter would become even more complicated when such outliers also become the founders of new clusters. Calculating interclade TMRCA’s would reduce to mere wishful thinking if typically the lifecycle of a subclade started indeed with a mutational STR boost being triggered by an induced mutation.
An example of unstable STR values due to a SNP mutation could be L148, a small subclade of U106+L48+. Comparing Eldon (y-search-id SFVPS), Cripps (BPBJQ) and Mitchell (YNWJ4) using the traditional STR interpretation would indicate Eldon’s haplotype closest to the ancestral haplotype for being closer to both Cripps and Mitchell. Still only Cripps has the normal (U106 modal) value DYS448=19, against the very rare value DYS448=15 for both other haplotyps. A genetic distance jump of GD=4! This giant backmutation to modal values in Cripps lineage suggests that the L148 mutation, when it happened, also involved at least one unstable STR mutation DYS448=15. If we could generalize on this we should be very careful indeed with deriving an age for a subclade using interclade STR calculations.
Statistic results of samples that include outliers would require higher-than-Zhivotovsky mutation rates to compensate for induced mutations. The investigation on Hutterites proved no calibation on mutation rates is necessary as long the outliers are discounted. Since STR dating assumes a predictable rate for spontaneous mutations, it is plain wrong to apply higher mutation rates for the sake of extreme STR fluctuations, even when observed in some documented, genealogic lineages.
More dating dangers are lurking. Multiple founders, cq. potential migrations instead of the gradual geographic expansion of a population, were mentioned by Myres et al. as another source of bias having TMRCA’s getting too old compared to the first occurrence of a subclade in a region. This notion may be important to Iberia, where the proposed LBK related Neolithic advance seems to collapse against unrelated Neolithic traditions at the time R1b is supposed to arrive.
One way to verify the true nature of haplogroup R1b’s advance through Europe is variance. Interpretation is hazardous, especially in relation to origin. This parameter measures the probability distribution of genetic distances compared to the mean. Unfortunately, variance alone won’t be enough to tell the difference between an increased effective population in the process of expansion, or an accumulated distribution of variability near its point of origin.
While often associated primarily with the potential origin of a haplogroup, the truth is that variance is highly sensitive to recent population history in particular, like processes that cause unequal growth and that tend to move away from a normal distribution. Isolated areas often show up with high variances and one-sided interpretation could make us believe that all humanity came from mountainous places like Scotland and Caucasus. Cosmopolitan areas on the other hand almost invariably show low variances. All depends on the success of certain haplotypes within a community, and the facility that successful lineages can also penetrate into the perifery and remote areas.
There is much more to variance than a tenuous indication of age. A subclade in region A having effective population size Na will develop a lower variance than in region B that has an effective population size Nb>Na, due to inbreeding and natural loss.
When the subclade expands from region A to region B, then it will be logical that B will soon develop a higher effective population, ie. a decreased loss via stochastic processes and inbreeding. The result will be that the variance increases most in the expansion areas. The corresponding diversity of haplotypes would be a star-structure, towards an increasing effective population size, thus higher variance at the rims.
Settled Neolithic populations in location A must have had a quite small effective population, almost per definition. This effective population basically consisted of those having the ownership of a small piece of arable land, and was typically stuck in small inbreeding communities.
On the other hand, the expanding part of the same population must have had almost unlimited growth possibilities for a while, thus creating a huge increase of the effective population in location B. At STR level this general situation for an expanding wavefront should comply to a star-structure and a corresponding increment of diversity and variance.
Also, a straightforward interpretation may be hampered by poor sampling that would make the prime assumption of Myres et al. tenuous, ie. that outliers should be excluded from the equation when calculating the age of a population.
This inadequacy of variance as a reliable and unequivocal measure of geographic age becomes dramatically clear when the data of Myres et al.(from table S2) is mapped into separate variance graphs for mutations U106 and P312, as has been done by Vincent Vizachero (acknowledged by Myres et al. “for alerting us to the potential of M520, M529, S116, L11, L23 SNPs and for insight regarding the DYS390, 19 repeat allele and M73″)
The R1b data of Myres et al. (table S2) becomes complicated and ambiguous once mapped separately into variance graphs for the components M412-, U106 and P312.
These varance graphs magnify inconsistencies that are difficult to reconcile with the Neolithic wave of advance. Indeed, the inconsistencies are so pronounced that it is hard to believe that the Neolithic advance is the only process that determined the current M412 distribution. It shouldn’t be surprising that now the variance of P312 and U106 (see above) could be interpreted as an indication of origin in western Europe.The absolute dates are debatable, but on a relative basis the variance graphs of P312 and U106 would indicated two separate, even contrary movements west to east against east to west that globally met each other at the axis East-Germany-Czechia-Croatia. Such results are at odds with the Neolithic advance that is the focus of current discussion, and no issue at all in the article of Myres et al. This doesn’t imply that variance is completely useless, but for sure this situation appeals to creativity.
Superficially the variance graph of P312 is more or less in agreement with the expected state of R1b at its arrival in western Europe, and – using one eye – can even be conciliated with the neolithic advance. Closer examination reveals that the peak values of P312 variance can be contributed almost exclusively to the U152 subclade. Even undifferentiated P312* seems to have attributed a lower variance. I figure the explanation could be that some relevant P312 subclades already existed at the eve of new expansions that eminated from central western Europe, and could have been post-Neolithic. This expansion inevitably involved a reduction of SNP diversity the further P312 moved away from such a purported expansion center in western Europe. This scenario for P312 would be in agreement with the predominance of subclade U152 towards the east and the predominance of subclade L21 towards the west.
The graph of U106 shows an increasing variance towards the eastern Donau region and beyond that superficially appears to be absolutely incongruent to the Neolithic advance. The graph could be reconciled with the western European focus of the P312 graph only if we just try to grasp the basics, that are quite ambiguous as far variance is concerned. Two mutually exclusive possibilities apply to U106:
- Western U106 is younger and didn’t accumulate as much variance, or:
- Western U106 suffered the limitations of a smaller effective population size compared to the expanding eastern part, that thus could build up an increasing variance and variability in a star-like fashion as a function of geographic distance from the source (Belgium?).
If we now just reverse the observations for P312 above then it looks likes U106 already started to expand before it was significantly differentiated. Expansion then involved an inevitable incremental increase of variability and variance. In the expansion areas formerly obscure lineages continued to expand in a star-like fashion. Indeed, I could show a remarkable relatedness of western U106 haplotypes “in the centre of the star” with respect to eastern haplotypes that exceed the internal relatedness of eastern haplotypes, insinuating that the center of expansion of U106 is indeed Western Europe.
BTW., the same ambiguity about variance as an indicator of population history could be emphasized for Iberian P312*:
- At the end of the wave of advance, Iberian P312* could be younger when it didn’t accumulate as much variance over time, or:
- Iberian P312* is older in NW Iberia and once settled, suffered the limitations of a smaller effective population size compared to an expanding U152 subclade, also essentially associated to expanding Bronze Age cultures (Iberian Bell Beaker). Only U152 could thus build up an increasing variance as a function of geographic distance from the (Iberian) source, at increasing variability in a star-like structure.
At this stage we should go back to the Myres et al. investigation and ask why M412 doesn’t comply to the star-structure one would expect with a truly Neolithic wave of advance.
- first there is the transition to M412 itself, that doesn’t really comply to the star-structure of a wave front that propagates in a semi-circular way. Myres et al. explains this bipolarity or dichotomy in European R1b1b2 as a surfing-effect along the wave.
- second there is a circular cline of variance for P312 that seems to emanate from the western Alps. Half of this cline runs in eastern direction, what would also violate the Neolithic star structure that is expected to run east to west, either way: taking variance as an unambiguous indicator of age or taking variance as an unambiguous indicator of increasing effective population size along the direction of the wave of advance.
- third there is the semi-circular cline of increasing variance of U106 in eastern direction. Since obviously this cline is unambiguous variance can be taken here as both supportive to the Neolithic advance (continuous surfing along the direction of the wave of advance, what is anyway a violation of the expected star-structure); or a violation of the Neolithic wave of advance by focussing on the star structure that is now contrary to the wave of advance.
- fourth there is a maximum variance in NW Iberia, that is predominantly P312*. There is no way that this could have reached Iberia through the Neolithic wave of advance, so the inflated TMRCA must have been caused by the multiple founders typical of migration. IMO this proves the oversea origin of Iberian Beaker from NW Europe, where in Belgium there is about the same situation of high variance P312*.
- fifth there is an untangible mix of P312* and large public P312+ subclades in the peak region of P312 variance nearing the western Alps. If this peak values are due to U152 then probably we could identify two different movements here:
- A Late-Neolithic movement of P312* emanating from the Paris Basin, conform the proposal of Myres et al. that links the Neolithic advance to LBK-derived cultures. This wave reaches a frequency peak in the Basque country, or rather Aquitaine where the Basques are supposed to originate, where such the peak would be expected. Also, since in Iberia the Neolithic influence was determined by the mediterranean Cardial Culture complex (often associated with a westward spread of haplogroup E), this continental R1b wave should be expected to stop here.
- Another movement in opposite direction bringing P312+ subclades having a star-structure in eastern direction, emanating from the west. This wave must have been younger and IMO originates ultimately in NW Iberia (not the Basque country).
R1b variance graph of Balaresque et al.indicates a higher variance in northwestern Iberia comparable to the values in northwestern Europe, what indeed would be in agreement with archeological indications towards the oversea, post-Neolithic link indicated by the Corded Beaker remains in Castelo Velho, Northern Protugal, at rock bottom (Susana Oliveira Jorge, 2001) and the Beaker remains in La Soria that according to Rojo-Guerra et al. (2005) has its best parallels in French Brittany, and ultimately in the Corded Ware complex (“Su decoración de líneas horizontales y paralelas a lo largo del vaso y su peculiar forma tienen sus mejores paralelos en la Bretaña francesa, y en última instancia en la Cerámica cordada”)
Are we here on the verge of a breakthrough that links the Neolithic advance to a common European Beaker culture, tied together by a single SNP of R1b – ie. M412?
Desde nuestro punto de vista esta tendencia tipológica tiene su origen en última instancia en los perfiles característicos de los vasos de la Cultura de la Cerámica Cordada, en los que esas características se muestran de forma mucho más marcada (…)
In our point of view, this typological tendency [i.e.narrow neck and low belly] has its origen ultimately in the characteristic profiles of the beakers of the Corded Ware culture, where these characteristics are much more noticeable.
En lo que respecta a la decoración, y más allá de la obvia derivación del patrón lineal de los esquemas cordados, es posible encontrar los paralelos más cercanos de la ornamentación de nuestro vaso en una curiosa variante regional del Campaniforme típica de la Bretaña francesa, con derivaciones hacia las regiones aledañas, que se caracteriza precisamente por el empleo de líneas horizontales y paralelas impresas, de forma corrida por toda la superficie externa del recipiente, como única decoración (…)
Regarding the decoration, beyond the obvious derivation of the linear patterns from the Corded schemes, it is possible to find parallels that are closer to the ornaments of our beaker [in central Spain] in a curious regional variety typical to the Bell Beaker style of French Brittany and its derivatives in the neighbourhood, that are characterized exactly by this application of horizontal lines and parallel imprintings, that run through the whole external surface of the beaker, being the only decoration.
The only difference is the tool employed for making the decoration:
todas las decoraciones campaniformes son impresas, lo único que varía es el instrumento empleado para ello: una cuerda en los tipos cordados, un peine de púas en los marítimos, y un peine liso en los hasta ahora llamados tipos incisos.
All bell beaker decorations are imprinted, the only difference is made by the employed tool: a cord for the corded prototypes, a dented comb for the maritime prototypes and a smooth tool for those prototypes that so far are known as incised.
The subsequent success of the Iberian Bell Beaker tradition and its hypothetical association to Atlantic Celts and Celto-Italic expansions deep into Central Europe, or possibly even much further, would for sure move us too far away from the Neolithic scope of this article. Still, it must be clear that unfortunately the Neolithic is not the only answer to all our questions. Actually, paleogenetic investigations (most notably the Lichtenstein Caves) didn’t confirm at all the predominance of R1b in prehistory. At the end the “R1b takeover” may have been a gradual, albeit inevitable process over thousands of years that was rather due to the disproportionate genetic contribution of the farming component to society. Even today in genealogy it can be observed that the most successful surnames derive from rural areas, having the owner of a farm as a founder – my own lineage started with a single obscure farmer and expanded to 2000 households worldwide within barely 500 years.
- Myres et al. – A major Y-chromosome haplogroup R1b Holocene era founder effect in Central and Western Europe, 2010, link or try here.
- Alison Sheridan – From Picardie to Pickering and Pencraig Hill? New information on the ‘Carinated Bowl Neolithic’ in northern Britain, 2007, link
- Pierre Allard – The Mesolithic-Neolithic transition in the Paris Basin : a review, 2007, link
- P. Balaresque et al. – A Predominantly Neolithic Origin for European Paternal Lineages, 2010, link
- L. Morelli et al. – A Comparison of Y-Chromosome Variation in Sardinia and Anatolia Is More Consistent with Cultural Rather than Demic Diffusion of Agriculture, 2010, link
- Cruciani et al. – Strong intra and inter-continental differentiation revealed by Y chromosome SNPs M269, U106 and U152, 2010, link or try here.
- European Society of Cardiology – Study links male Y chromosome variants with the risk of coronary heart disease, 2010, link
- S. Shoaib Shah et al. – Y haplogroups and aggressive behavior in a Pakistani ethnic group, 2008, link
- Mark A. Jobling and Chris Tyler-Smith – The Human Y Chromosome: An Evolutionary Marker Comes Of Age (2004), link
- Zhivotovsky et al. – Difference between Evolutionarily Effective and Germ line Mutation Rate Due to Stochastically Varying Haplogroup Size, 2006, link
- Rojo-Guerra et al. – Un peculiar vaso Campaniforme de estilo Marítimo del túmulo de La Sima, Miño de Medinaceli (Soria, España): Refleciones en turno de las técnicas decorativas Campaniformes y los sistemas de intercambios de larga distancia, 2005, link
- Susana Oliveira Jorge – An All-Over-Corded Bell Beake in Northern Portgal: CASTELO VELHO DE FREIXO DE NUMÃO (VILA NOVA DE FOZ CÔA): Some remarks, 2001, link
- Schilz – Molekulargenetische Verwandtschaftsanalysen am prähistorischen Skelettkollektiv der Lichtensteinhöhle, 2006, link