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Monthly Archives: December 2012

The expansion of Neolithic in Europe (synthetic maps)

This is relatively old material (2009) but the resuscitated Spanish-language blog Neolítico de la Península Ibérica has recently discussed and synthesized it. And I am sure that much of what is said in it is of great interest for readers of this blog, beginning with myself. Hence I’m including here some of the maps discussed there because they truly synthesize very well the big picture of European Neolithic as a discontinuous and highly irregular process.
Reference: Jean Pierre Bocquet-Appel, Detection of diffusion and contact zones of early farming in Europe from the space-time distribution of 14C dates. Journal of Archaeological Sciences, 2009. Pay per viewLINK [doi:10.1016/j.jas.2008.11.004]
Firstly a map of “vectors” of Neolithic influences/flows, showing some eight apparent zones of expansion:

The numbers may be misleading. The actual chronological order is (by oldest referenced C14 date, which must be calibrated BCE):
  1. Initial phase (Balcans essentially, roots in Thessaly):
    1. (1) Thessaly c. 7100 BCE → Sesklo culture
    2. (2) Hungary c. 6800 BCE → transition between Balcanic and Danubian Neolithic
  2. Main explosion (with Balcanic roots for both Danubian and Impressed-Cardial cultures but unclear for Megalithism):
    1. (8) West Iberia c. 5900 BCE → Megalithism (the ref. site, Cha de Carvalhal, is a mamoa or tumulus, cairn, usually with a dolmen inside)
    2. (6) Liguria c. 5800 BCE → Cardial Pottery Neolithic
    3. (5) SE France c. 5700 BCE → Cardial Pottery Neolithic
    4. (3, 4) Bavaria and Luxembourg c. 5400 BCE → Danubian Neolithic
    5. (7) SE Iberia c. 5300 BCE → Cardial Pottery Neolithic
  3. Late Atlantic offshoots (Atlantic, North Sea):
    1. (9) Ireland c. 4600  BCE → Megalithism
    2. (10) Scotland c. 4100 BCE → Megalithism
The exact chronology for Southern European Neolithic, very especially in Iberia, where some dates insist on being pre-Cardial, is yet to be properly determined but whatever the case it is older or contemporary from the more popular Danubian Neolithic of Central Europe.
Many details are obviously not addressed here, so always take this kind of general approaches with some caution: the devil is often in the details, and many details are missing here.
Still I do feel that the overall description of the process is quite realistic, notably when we also consider this other map that provides a much more clear cultural contextualization:

Legend:
1.- expansion centers
2.- contact zones
3.- ecological/cultural barriers
4.- maritime expansion route from West Asia
5.- Painted Pottery Neolithic (Balcans)
6.- Eastern Lineal Pottery (Tisza)
7.- Western Lineal Pottery (Danubian Neolithic, LBK)
8.- Impressed Pottery (Adriatic)
9.- Cardial Pottery (Western Mediterranean)
10.- Adriatic contact zone
11.- Western contact zone
The maps are very educative if nothing else. However particular caution must be warned, not just about the many highly debatable details but very notably on the nature of Eastern European Neolithic, often not well described in these analysis, whose most representative culture is Dniepr-Don (located in the basins of these two rivers in Ukraine and Russia mostly) and whose genesis seems very locally rooted (what is emphasized by the persistence of hunter-gathering even after farming and herding and pottery have been consolidated). This culture was also very influential in its own way (alone or later with/under the maybe related Samara-Khvalynsk culture: proto-Indoeuropeans, whose ultimate origins remain in wait of archaeological work). 
 

Genetic isolates from Friuli

Just a quick mention of this paper on selected rare populations of Friuli because I totally fail to see the angle of interest in this paper, yet, together with other data may be of interest for European population genetics… potentially.
Tõnu Esko et al., Genetic characterization of northeastern Italian population isolates in the context of broader European genetic diversity. European Journal of Human Genertics, 2012. Open accessLINK [doi: 10.1038/ejhg.2012.229]

Abstract


Population genetic studies on European populations have highlighted Italy as one of genetically most diverse regions. This is possibly due to the country’s complex demographic history and large variability in terrain throughout the territory. This is the reason why Italy is enriched for population isolates, Sardinia being the best-known example. As the population isolates have a great potential in disease-causing genetic variants identification, we aimed to genetically characterize a region from northeastern Italy, which is known for isolated communities. Total of 1310 samples, collected from six geographically isolated villages, were genotyped at >145 000 single-nucleotide polymorphism positions. Newly genotyped data were analyzed jointly with the available genome-wide data sets of individuals of European descent, including several population isolates. Despite the linguistic differences and geographical isolation the village populations still show the greatest genetic similarity to other Italian samples. The genetic isolation and small effective population size of the village populations is manifested by higher levels of genomic homozygosity and elevated linkage disequilibrium. These estimates become even more striking when the detected substructure is taken into account. The observed level of genetic isolation in Friuli-Venezia Giulia region is more extreme according to several measures of isolation compared with Sardinians, French Basques and northern Finns, thus proving the status of an isolate.

Fig. 2
Model-based mapping convergence with SPA. Label position indicates the (a) specific PC1 and PC2 coordinate values for each individual and (b) the mean PC1 and PC2 coordinate values for each population. For (a, b),
the colors have a following meaning: (1) dark blue color: a homogeneous
fraction of the FVG population; a blue color: more general fraction of
the FVG population; a red color: other Italian samples; a violet color:
Basques; an orange color: Slovenians; and green color: all other
populations. For (a, b), the following population abbreviation
labels are used: AT, Austrians; BA, French Basques; BG, Bulgarians; BO,
Borbera; CA, Carlantino; CL, Clauzetto; CH, Swiss; CZ, Czechs; GR,
Germans; ER, Erto; ES, Spaniards; FR, French; HU, Hungarians; IL,
Illegio; IT, Italians; JW_A, Ashkenazy Jews; JW_S, Sephardic Jews; OR,
Orcadians; RE, Resia; RO, Romanians; SA, Sardinians; SA_, Sauris; SMC,
San Martino del Carso; SI, Slovenians; TU, Tuscans. The extra
abbreviations: N, northern; S, southern; I, a more homogeneous
sub-population; G, a more general sub-population.

 
3 Comments

Posted by on December 21, 2012 in autosomal DNA, Europe, Italy, West Eurasia

 

Mitochondrial DNA haplogroup Q in Oceania

Even if a very specialized detail, this lineage may help to shed light on the colonization of Oceania:
Chris A. Corser et al., The Q2 Mitochondrial Haplogroup in Oceania. PLoS ONE 2012. Open accessLINK [ doi:10.1371/journal.pone.0052022]

Abstract

Many details surrounding the origins of the peoples of Oceania remain to be resolved, and as a step towards this we report seven new complete mitochondrial genomes from the Q2a haplogroup, from Papua New Guinea, Fiji and Kiribati. This brings the total to eleven Q2 genomes now available. The Q haplogroup (that includes Q2) is an old and diverse lineage in Near Oceania, and is reasonably common; within our sample set of 430, 97 are of the Q haplogroup. However, only 8 are Q2, and we report 7 here. The tree with all complete Q genomes is proven to be minimal. The dating estimate for the origin of Q2 (around 35 Kya) reinforces the understanding that humans have been in Near Oceania for tens of thousands of years; nevertheless the Polynesian maternal haplogroups remain distinctive. A major focus now, with regard to Polynesian ancestry, is to address the differences and timing of the ‘Melanesian’ contribution to the maternal and paternal lineages as people moved further and further into Remote Oceania. Input from other fields such as anthropology, history and linguistics is required for a better understanding and interpretation of the genetic data.

Figure 2. Overview of the Q haplogroup.
The dataset has 36 mitochondrial genomes including all eight Q3 sequences, 17 Q1, three Q2 genomes from Friedlaender et al. [28], one from Hudjashov et al. [36],
together with the seven additional Q2a genomes reported here. The
network has been proved the shortest possible (the minimum number of
mutations) by using the techniques in Pierson et al. [40]. Differences in branching between the four equally parsimonious trees occur in the Q3 subgroup.

See also in this blog:

 
82 Comments

Posted by on December 21, 2012 in mtDNA, Oceania

 

Hominid speciation: sudden or gradual?

It depends apparently: bonobos may have diverged quite suddenly while in other cases, including the Pan-Homo split, the process of speciation appears to have been more gradual.

Thomas Mailund et al., A New Isolation with Migration Model along Complete Genomes Infers Very Different Divergence Processes among Closely Related Great Ape Species. PLoS ONE 2012. Open access LINK [doi:10.1371/journal.pgen.1003125]

Abstract

We present a hidden Markov model (HMM) for inferring gradual isolation
between two populations during speciation, modelled as a time interval
with restricted gene flow. The HMM describes the history of adjacent
nucleotides in two genomic sequences, such that the nucleotides can be
separated by recombination, can migrate between populations, or can
coalesce at variable time points, all dependent on the parameters of the
model, which are the effective population sizes, splitting times,
recombination rate, and migration rate. We show by extensive simulations
that the HMM can accurately infer all parameters except the
recombination rate, which is biased downwards. Inference is robust to
variation in the mutation rate and the recombination rate over the
sequence and also robust to unknown phase of genomes unless they are
very closely related. We provide a test for whether divergence is
gradual or instantaneous, and we apply the model to three key divergence
processes in great apes: (a) the bonobo and common chimpanzee, (b) the
eastern and western gorilla, and (c) the Sumatran and Bornean
orang-utan. We find that the bonobo and chimpanzee appear to have
undergone a clear split, whereas the divergence processes of the gorilla
and orang-utan species occurred over several hundred thousands years
with gene flow stopping quite recently. We also apply the model to the Homo/Pan speciation event and find that the most likely scenario involves an extended period of gene flow during speciation.

 
 

Iberian Neolithic blog (Spanish language) is back online

Several readers have asked me in this last year about links to the most interesting blog Neolítico de la Península Ibérica (essentially in Spanish language), occasionally mentioned here, which has been down (unaccessible because the author wanted it that way) for many months. 
I am very glad to announce that it is now back with nothing less than three new entries in a row (which I had not time to read yet):
 
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Posted by on December 21, 2012 in blogging, Iberia, Neolithic

 

Did the human hand evolve for boxing (too)?

That is the intriguing conclusion of a new study:
Michael H. Morgan and David R. Carrier, Protective buttressing of the human fist and the evolution of hominin hands. The Journal of Experimental Biology, 2012. Freely accessibleLINK [doi: 10.1242/​jeb.075713 ]


Summary

The derived proportions of the human hand may provide supportive
buttressing that protects the hand from injury when striking
with a fist. Flexion of digits 2–5 results in
buttressing of the pads of the distal phalanges against the central palm
and
the palmar pads of the proximal phalanges.
Additionally, adduction of the thenar eminence to abut the dorsal
surface of the
distal phalanges of digits 2 and 3 locks these
digits into a solid configuration that may allow a transfer of energy
through
the thenar eminence to the wrist. To test the
hypothesis of a performance advantage, we measured: (1) the forces and
rate
of change of acceleration (jerk) from maximum
effort strikes of subjects striking with a fist and an open hand; (2)
the static
stiffness of the second metacarpo-phalangeal (MCP)
joint in buttressed and unbuttressed fist postures; and (3) static force
transfer from digits 2 and 3 to digit 1 also in
buttressed and unbuttressed fist postures. We found that peak forces,
force
impulses and peak jerk did not differ between the
closed fist and open palm strikes. However, the structure of the human
fist
provides buttressing that increases the stiffness
of the second MCP joint by fourfold and, as a result of force transfer
through
the thenar eminence, more than doubles the ability
of the proximal phalanges to transmit ‘punching’ force. Thus, the
proportions
of the human hand provide a performance advantage
when striking with a fist. We propose that the derived proportions of
hominin
hands reflect, in part, sexual selection to improve
fighting performance. 
 

I wouldn’t dare to comment much but for what I have read in the paper, it looks plausible, notably because it is indeed significantly efficient versus the open hand (as much as 3x) and because chimpanzees can’t do it… but australopithecines could. 
However I can also imagine this development as a side-effect of other adaptive uses of the hand, such as grabbing a spear, which is no doubt a much more daunting weapon than a naked fist… in most cases at least.
Fig. 2
 
7 Comments

Posted by on December 20, 2012 in biology, hand, human evolution

 

Neolithic wooden wells from Germany

Several wooden wells from Germany have been precisely dated by archaeologists, yielding not only very revealing information from the first farmers of that area (and by extension of all Europe) and their construction techniques but also most valuable paleoclimatic information from the reconstructed and precisely dated tree rings.
Figure 1. Wooden well constructions and Neolithization.
LBK wells from (A) Eythra 1, (B) Eythra 2, (C) Brodau 1, and (D) Altscherbitz. (E) Central European loess distribution [20] with the superimposed phases of expansion of the LBK (lines), based on 14C dates [22],
and the maximum extension of the LBK (light blue) along with the 12
known early Neolithic wells featuring waterlogged wood preservation.

Willy Tegel et al. Early Neolithic Water Wells Reveal the World’s Oldest Wood Architecture. PLoS ONE 2012. Open accessLINK [doi:10.1371/journal.pone.0051374]

Abstract

The European Neolithization ~6000−4000 BC represents a pivotal change in human history when farming spread and the mobile style of life of the hunter-foragers was superseded by the agrarian culture. Permanent settlement structures and agricultural production systems required fundamental innovations in technology, subsistence, and resource utilization. Motivation, course, and timing of this transformation, however, remain debatable. Here we present annually resolved and absolutely dated dendroarchaeological information from four wooden water wells of the early Neolithic period that were excavated in Eastern Germany. A total of 151 oak timbers preserved in a waterlogged environment were dated between 5469 and 5098 BC and reveal unexpectedly refined carpentry skills. The recently discovered water wells enable for the first time a detailed insight into the earliest wood architecture and display the technological capabilities of humans ~7000 years ago. The timbered well constructions made of old oak trees feature an unopened tree-ring archive from which annually resolved and absolutely dated environmental data can be culled. Our results question the principle of continuous evolutionary development in prehistoric technology, and contradict the common belief that metal was necessary for complex timber constructions. Early Neolithic craftsmanship now suggests that the first farmers were also the first carpenters.

I would not dare to claim as much as they say in the last sentence because we do know of Epipaleolithic carpentry in form of boats and rows as well, and let’s not forget what we know of the Neanderthal carpentry including wooden walls and utensils. But it is later revealed in the conclusions that their intention is more to compare with the Metal Ages than with the Paleolithic:
This study demonstrates that the first farmers were also the first
carpenters, contradicting the common belief that the invention of metal
woodworking tools more than a thousand years later was imperative for
complex timber constructions. Settlers of the early Neolithic time were
able to build sophisticated corner joints and log constructions, which
fulfilled all of the static requirements of massive water well linings.
Their technical skills further imply the existence of complex
constructions for LBK longhouse architecture [35].
But the wells and their techniques are anyhow interesting, very especially because we do not get to see such well preserved ancient pieces of wood but seldom. Both cogged and mortise-and-tenon unions were used in the construction of the wells. 
Figure 5. Basal frame construction of well A.
(A) Wedged tusk tenon joint. (B) 3D laser rendering of the basal frame.

Well A (Eythra, Saxony) not only displays these innovative mortise-and-tenon (wedged variant) joints but the comparison of the age of its timbers with others used in the surrounding area, indicate a settlement of at least one century, suggesting that the villages of the Danubian Neolithic were anything but provisional.