RSS

Category Archives: West Asia

Are ancient mtDNA sequences from Syria of Indian origin?

Honestly, I have all kind of doubts but that’s what a new study claims on the basis of just a few hypervariable sequence markers:
Henry W. Witas, mtDNA from the Early Bronze Age to the Roman Period Suggests a Genetic Link between the Indian Subcontinent and Mesopotamian Cradle of Civilization. PLoS ONE 2013. Open accessLINK [doi:doi:10.1371/journal.pone.0073682]
The authors sequenced the HVS-I (and nothing else!) of the mtDNA of four individuals from Tell Ashara and Tell Ashaik sites of ancient Terqa and Kar-Assurnasirpal (Syria, Euphrates river). And then they proceded to establish a bit unlikely comparisons with East and South Asian M sublineages, of which only one is present today in the region.
The sequences are (supp table 3, all numbers +16,000 and counting from the CRS, i.e. H2a1 underived, GenBank: NC_012920):
  • TQ28F112: 223-234
  • MK13G117: 223-234-311
  • TQ28F256: 223-234-270
  • MK11G107: 223-266-289
The first two are attributed to M9, the third one to M61 (a quite rare haplogroup) and the last one to M4b (the only one to be found in West Asia nowadays, specifically in Arabia Peninsula).
Now what do the markers actually say? All are highly variable sites and independently can be found in many lineages, however most typically:
  • 223 describes R, hence counting from the CRS, it should mean L(xR).
  • 311 describes L3, hence counting from the CRS it should mean L(xL3).

So all four should be L(xR) and MK13G117 looks like L(xL3).
Exceptions for 311 (consistent with the sequence above): L3b1a3, M4’65’67, M10, M29’Q, M31a1, M56, M57 and M74. However M9 does not make it because to begin with it needs a transition at the 362 site. 
The authors got carried away by their own pre-conceptions and the marker 234, shared by three of the four sequences. However, while that marker is found in M9a, it also needs the 362 marker, which they both lack. So they are not M9 but something else. 

More plausible candidates could be, at least for TQ28F112, M30d/e or M49.
As for the rest, there are no modern sequences, at least via PhyloTree (but neither within the study’s own comparisons), that are good correlates. All we can say with certainty is that they are L3(xR), except in the case of MK13G117, which can only be described as  L(xR). 
Maybe if they had tried sequencing the coding region, as in my understanding, they MUST (destroying or damaging valuable ancient bones to do this mediocre research is not anymore justified, if it ever was), they would have got useful and informative results. Now we just have again another frustrating set of nearly useless HVS-I sequences, which can only be ambiguous in the vast majority of cases.
Ah, by the way, there’s no obvious correlation between these Metal Ages’ sites and ancient Sumerians, of course. Even if the lineages are South Asian by origin or affinity, which is possible but by no means demonstrated, they would at most suggest a relation between the Mid-Upper Euphrates and that area. The region was under intermittent Sumerian, Amorite, Babylonian, Kassite and Assyrian control but mostly is a distinct country within the greater Mesopotamian area.
Notice that previous research (ref.) in the same area but from the Neolithic (PPNB) period has found (also HVS-I) large amounts of mtDNA K, some H and also some L3(xR).

[Note: edited because some ethnographic assumptions I made initially seem to be quite wrong].

 
4 Comments

Posted by on September 12, 2013 in aDNA, Bronze Age, Iron Age, Kurdistan, mtDNA, Syria, West Asia

 

Pre-pottery Neolithic in North-Central Arabia

And yet another Cressard study, this time on the Neolithic of North-Central Arabia Peninsula.
Rémy Cressard et al., Beyond the Levant: First Evidence of a Pre-Pottery Neolithic Incursion into the Nefud Desert, Saudi Arabia. PLoS ONE 2013. Open access → LINK [doi:10.1371/journal.pone.0068061]
Abstract

Pre-Pottery Neolithic assemblages are best known from the fertile areas of the Mediterranean Levant. The archaeological site of Jebel Qattar 101 (JQ-101), at Jubbah in the southern part of the Nefud Desert of northern Saudi Arabia, contains a large collection of stone tools, adjacent to an Early Holocene palaeolake. The stone tool assemblage contains lithic types, including El-Khiam and Helwan projectile points, which are similar to those recorded in Pre-Pottery Neolithic A and Pre-Pottery Neolithic B assemblages in the Fertile Crescent. Jebel Qattar lies ~500 kilometres outside the previously identified geographic range of Pre-Pottery Neolithic cultures. Technological analysis of the typologically diagnostic Jebel Qattar 101 projectile points indicates a unique strategy to manufacture the final forms, thereby raising the possibility of either direct migration of Levantine groups or the acculturation of mobile communities in Arabia. The discovery of the Early Holocene site of Jebel Qattar suggests that our view of the geographic distribution and character of Pre-Pottery Neolithic cultures may be in need of revision.
Figure 1. Map of the Neolithic Near East with the
different geo-cultural zones of the core area (or Fertile Crescent), in
green; after Aurenche and Kozlowski [82].

The JQ-101 site is located in the southern part of the Nefud Desert in Saudi Arabia.

Critically the Jebel Qattar site includes characteristic fossils: the El Khiam and Heluwan points, that link it clearly to the Southern Levant (i.e. Palestine and Jordan). This may relate this colonization with proto-Semitic or very early Semitic peoples, which are often suspected to be related to these cultures. In particular I wonder if these peoples may have been already carrying the seed of the Southern Semitic languages which once extended through Southern Arabia and parts of The Horn of Africa (now restricted mostly to Eritrea and Ethiopia, although still surviving among the Mehri and Socotran).
 
Leave a comment

Posted by on August 1, 2013 in Arabia, Neolithic, West Asia

 

South Arabian paleolake Mundafan was inhabited in the Middle Paleolithic and later in the Neolithic

Another study also by Cressard researches two greatly different periods of occupation of what was once a lake in Southern Saudi Arabia, not far from Yemen.
Rémy Cressard et al., Middle Palaeolithic and Neolithic Occupations around Mundafan Palaeolake, Saudi Arabia: Implications for Climate Change and Human Dispersals. PLoS ONE 2013. Open accessLINK [doi:10.1371/journal.pone.0069665]

Abstract

The Arabian Peninsula is a key region for understanding climate change and human occupation history in a marginal environment. The Mundafan palaeolake is situated in southern Saudi Arabia, in the Rub’ al-Khali (the ‘Empty Quarter’), the world’s largest sand desert. Here we report the first discoveries of Middle Palaeolithic and Neolithic archaeological sites in association with the palaeolake. We associate the human occupations with new geochronological data, and suggest the archaeological sites date to the wet periods of Marine Isotope Stage 5 and the Early Holocene. The archaeological sites indicate that humans repeatedly penetrated the ameliorated environments of the Rub’ al-Khali. The sites probably represent short-term occupations, with the Neolithic sites focused on hunting, as indicated by points and weaponry. Middle Palaeolithic assemblages at Mundafan support a lacustrine adaptive focus in Arabia. Provenancing of obsidian artifacts indicates that Neolithic groups at Mundafan had a wide wandering range, with transport of artifacts from distant sources.

Figure 5. General views of the Mundafan palaeolake.
Again the content is rich in details of great interest for the archaeologist and prehistorian but surely a bit harder to digest for the casual aficionado.
Of interest anyhow is that no Nubian Complex affinities have been observed in the Middle Paleolithic tools and cores, suggesting again that the colonization of Arabia and Palestine from Africa was multifaceted, with different and sometimes ill-defined cultural sources.
As for the Neolithic a problem is that in this and other sites, all findings are located on the surface, being therefore impossible to date stratigraphically. The kind of tanged arrowheads suggests, by comparison with other sites, that these findings belong to the oldest Neolithic phase, c. 8000-6000 calBP. There are no findings that could be attributed to later periods, probably because the area became just too dry. Interestingly:

The Mundafan Neolithic sites do not appear to be sedentary locations on the basis of the absence of architectural features, grindstones, domesticated faunal remains, and relatively low artifact densities. The prevalence of projectiles and other weaponry is probable evidence of hunting activities. Mundafan would have been a favorable setting for short-term hunting along the lakeshore. The presence of rare obsidian artifacts demonstrates Mundafan’s participation in long-distance mobility systems that included relations with the obsidian-rich mountainous zones of Yemen, some 400–500 km away from the site.

While the term “Neolithic” is used in the paper, the kind of economy that the people living there had seems to have been hunter-gatherer.
 
Leave a comment

Posted by on August 1, 2013 in Arabia, Middle Paleolithic, Neolithic, West Asia

 

Nubian Complex in Central Arabia

The Nubian Complex MSA techno-culture arrived to Central Arabia, just south of Riyadh seemingly via the South
Rémy Cressard & Yamandú H. Hilbert, A Nubian Complex Site from Central Arabia: Implications for Levallois Taxonomy and Human Dispersals during the Upper Pleistocene. PLoS ONE 2013. Open accessLINK [doi:10.1371/journal.pone.0069221]

Abstract

Archaeological survey undertaken in central Saudi Arabia has revealed 29 surface sites attributed to the Arabian Middle Paleolithic based on the presence of Levallois blank production methods. Technological analyses on cores retrieved from Al-Kharj 22 have revealed specific reduction modalities used to produce flakes with predetermined shapes. The identified modalities, which are anchored within the greater Levallois concept of core convexity preparation and exploitation, correspond with those utilized during the Middle Stone Age Nubian Complex of northeast Africa and southern Arabia. The discovery of Nubian technology at the Al-Kharj 22 site represents the first appearance of this blank production method in central Arabia. Here we demonstrate how a rigorous use of technological and taxonomic analysis may enable intra-regional comparisons across the Arabian Peninsula. The discovery of Al-Kharj 22 increases the complexity of the Arabian Middle Paleolithic archaeological record and suggests new dynamics of population movements between the southern and central regions of the Peninsula. This study also addresses the dichotomy within Nubian core typology (Types 1 and 2), which was originally defined for African assemblages.

Figure 3. Levallois methods schemata: figuration of product and core shapes for each method.
A:
Preferential Levallois flake production with centripetal preparation;
B: Preferential Levallois point production with unidirectional
convergent preparation; C: Nubian Levallois type 1 with distal divergent
preparation; D: Nubian Levallois type 2 with double lateral
preparation; E: Nubian Levallois type 1/2 with mixed type 1 and type 2
preparation.
Figure 10. Schematic representation depicting the
three main dorsal preparation types, preparation type 1, 2 and 1/2, and
the proposed reduction succession discussed in the text.

In
order to facilitate comprehension cores, end-products and preparation
by-products have been color-coded; blue equals type 1 preparation, green
type 2 and yellow type 1/2.

Many more images of interest for experts or qualified amateurs are available in this high quality study. For the less specialized reader it is probably more interesting to ponder the overall extension of the Nubian Complex:

Figure 11. Distribution of main sites with Nubian cores in Eastern Africa and Arabia.
Illustrated cores do not represent actual size. 1. Al-Kharj 22 (this study); 2. Aybut Al Auwal [12]; 3. Shabwa [30]; 4. Hadramawt [5], [6], [27]; 5. Aduma [112]; 6. Gademotta [113]; 7. Asfet [114]; 8. Nazlet Khater 1 [115]; 9. Abydos [66].

The authors argue that Southern and Central Arabia are the Easternmost reaches of this complex, however we cannot forget that the recent discovery of Indian sites with a complex industry, dated to c. 96 Ka ago, of Nubian, Aterian and other MSA affinities challenges this notion.

See also in this blog:

 
 

New evidence from Luristan reveals that Neolithic Revolution was almost simultaneous across the Fertile Crescent

Wild barley from Chogha Golan
The new sites, in the Southern Zagros mountain country of Luristan (Iran), evidence local development of agriculture between 12,000 and 9800 BP:

The plant remains found at the Chogha Golan site document more than 2,000 years of the region’s land use and represent the earliest record of long-term plant management in Iran, according to the researchers. The site’s excavation, which was conducted by archaeologists from the University of Tübingen and the Iranian Center for Archaeological Research between 2009 and 2010, shows that Chogha Golan’s early inhabitants cultivated wild barley, wheat, lentil and grass peas—and eventually domesticated emmer wheat—during their occupation, which began about 12,000 years ago.

Plentiful findings of chaff remains of the cereals indicate that people processed their harvest within the sites they were living in,” Riehl said. “Mortars and grinding stones may have been used for turning the grain into some kind of bulgur or flour, which may have been further processed either by cooking or roasting.” (The author also notes, however, that chemical studies of the grinding tools showed that they were multi-purpose—not just for processing plant materials.)

Annotation on study’s map. 
Earliest Neolithic areas in red (previously known) and in blue (new ones). Notice that Jarmo is not usually considered (against what the legend says) part of PPNA, but a different locally rooted culture altogether. There are doubts on whether PPNA was a productive or just Mesolithic cereal-gatherer economy.
Consolidated Neolithic: The green dotted line marks the max. extension of PPNB, which was not the only consolidated Neolithic culture: earliest Balcanic and South Asian Neolithic were already ongoing by that time (8th millenium BCE), while in Africa it should be not much more recent. In lowland Mesopotamia the sediments have so far hidden any cultural phase prior to the already highly developed Ubaid culture, the first known civilization.
East Asia and Papua had their own distinct Neolithic developments of similar time-frame.

Source: Past Horizons.
Ref. S. Riehl et al. Emergence of Agriculture in the Foothills of the Zagros Mountains of Iran. Science Magazine 2013. Pay per viewLINK [doi:10.1126/science.1236743]
 
Leave a comment

Posted by on July 7, 2013 in Iran, Neolithic, West Asia

 

South Arabian genetic refugium

This is not about the L(xM,N) lineages but about the Eurasian ones like R0a or R2.
Jeffrey I. Rose et al., Tabula rasa or refugia? Using genetic data to assess the peopling of Arabia. Arabian Archaeology and Epigraphy, 2013. Pay per view → LINK [doi:10.1111/aae.12017]

Abstract


This paper provides a broad overview of the current state of archaeogenetic research in Arabia. We summarise recent studies of mitochondrial DNA and lactase persistence allele -13915*G in order to reconstruct the population histories of modern Arabs. These data, in turn, enable us to assess different scenarios for the peopling of the Peninsula over the course of the Late Pleistocene and Early Holocene. The evidence supports the posited existence of Arabian refugia, although it is inconclusive which (e.g. Persian Gulf basin, Yemeni highlands and/or Red Sea basin) was/were responsible for housing ancestral populations during the Last Glacial Maximum. Synthesising genetic and archaeological data sets, we conclude that a substantial portion of the present South Arabian gene pool derives from a deeply rooted population that underwent significant internal growth within Arabia some 12,000 years ago. At the same time, we interpret the disappearance of Nejd Leptolithic archaeological sites in southern Arabia around 8000 years ago to represent the termination of a significant component of the Pleistocene gene pool.

Rose uploaded the full paper at Academia.edu. Very much worth a careful read because it is a rare case of paleogenetics being done by a researcher who is primarily an archaeologist and who knows well the material Prehistory of which he’s talking about, at all moments seeking to reconcile archaeological and genetic evidence and not, as way too often happens, creating genetic-only models with absolutely no material foundations and unavoidably clashing with prehistoric reality.  
 
 

Synthesis of the Spanish-language series on the expansion of H. sapiens (2)

One of the reasons I have been a bit too saturated and maybe not writing as much as usual is that I am collaborating in a series in Spanish language for the blog Noticias de Prehistoria – Prehistoria al Día.
I already mentioned last month the initial article[es] of the series by David Sánchez, which dealt with the African Middle Paleolithic (MSA, Lupembian, Aterian, etc.) We have not been idle in the meantime but actually wrote a number of other articles that may well be of your interest:
There is still a lot to do for the series to be complete but the time for a synthetic review in this blog is quite overdue. I will skip the brief intro to population genetics on the belief that most readers here have a decent idea, but the other three articles ask for due mention.

Expansion of H. sapiens in Africa (genetic viewpoint)

This is something that complements David’s analysis of the African MP and that to a great extent I dealt with already at my former blog Leherensuge. I like graphs and maps because they often tell more than just words:

Basic mtDNA tree of Humankind
Branch length is proportional to coding region mutations from root per PhyloTree v.15 (L0k excepted)

We can see in this graph two main “moments” of diversification or expansion:
  1. The L0 and L2-6 nodes, followed soon by the L1 and L0a’b’f’k nodes
  2. The L0a’b’f, L0d and L2’3’4’6 nodes
The latter may well be calibrated with the archaeological evidence for the arrival of H. sapiens (MSA) to Southern Africa (L0d), which may be as old as 165 Ka but shows a clear increase in density since c. 130 Ka. I’d rather lean for the later date, that is roughly coincidental with the beginning of the Abbassia Pluvial, which must have provided good opportunities for expansion also in more northernly latitudes (the other nodes).
The first expansion is harder to estimate but c. 160 Ka. is a time in which we can see some of the first signs of expansion of our species within Africa (Jebel Irhoud and the already mentioned first Southern African MSA) so it is a tentative date. 
The geography of both expansions should be as follows (based on the raw data of Behar 2008):

Approx. geography of the first expansion of H. sapiens
(Purple dotted area indicates the max. likelihood for ‘mtDNA Eve’ location)
Approx. geography of the second expansion of H. sapiens

I also mentioned the expansion of L3, which preludes the migration Out of Africa, but this was already discussed in this entry.

Arrival to Arabia and Palestine

While most of the entries I am doing for this series deal with the genetic aspects, in this case I worked mostly with the archaeology, recycling many materials that are readily available in this blog and achieving the following synthetic map (recycling one by Armitage 2011) as central element of the article:

In addition to reviewing the archaeological discoveries of the last few years (and few older ones) I also discussed the issue of Neanderthal admixture, which most likely happened in this phase, and the possibility of some L(xM,N) lineages found in Arabia being from this period (see here).

Synthesis of Asian Prehistory

The last article so far in the series, authored by David Sánchez, has been published just today and is a very good visual review of the complex archaeological record of most of Asia in the period that interests us (most Middle Paleolithic with marginal mention of the earliest UP of West Asia, Siberia and neighboring areas, which will be reviewed more in depth in later articles). Probably the maps say it all, although we must understand that they only consider the best known sites:

Prior to Toba event (120-74 Ka BP)
(open circles: human remains, dots: other archaeological sites)
(notice that the date of Narmada hominin is most unclear, what is not reflected in the map)
Blue: 74-45 Ka BP
(stars: Neanderthal sites, open circles: other human remains, dots: archaeological sites, black: previous map)
Red: 45-35 Ka BP
(stars: neanderthal sites, open circles: other human remains, dots: archaeological sites, black & blue: previous maps)
Green: later expansion of H. sapiens in Northern Asia
(stars: Neanderthals, open circles: other human remains, dots: other archaeological sites, black, blue & red: previous maps)

I must say that the design of the maps is not quite the way I would have done myself but is still interesting. Very especially I miss lots of info on post-Toba South Asia. Also the Altai transition is not really well explained in my understanding. On the other hand East Asia is full of details and the overall picture of the archaeology of the Eurasian expansion is well described nonetheless.

PS- from the commentaries by David at his blog, it seems clear that he gives for granted the occupation of South Asia after Toba and therefore he did not consider it important to mark any more recent sites in the subcontinent. 

     

    Bronze Age settlement unearthed in Azerbaijan

    The site of Aghgabirli (Kichik Dahna, near Shaki) was inhabited for some 2000 years beginning at the end of the 3rd millennium BCE and shows two cultural layers, including the signature of at least two floods. They were dedicated mostly to animal husbandry and no metal remains have been found as of yet. 

    Source: The Archaeology News Network (via Pileta).

     

    West Asian autosomal genetics: two cluster confimed

    You may be familiar with my understanding (also suggested by others, I guess) that West Asia has (at least) two ancient populations whose spread now overlaps but is relatively easy to discern. A clear example is the duality between Y-DNA haplogroups J1 (south/SW or lowlands) and J2 (north/NE or highlands). To my knowledge this is however the first study that formally asserts that duality for autosomal DNA.


    Marc Haber et al., Genome-Wide Diversity in the Levant Reveals Recent Structuring by Culture. PLoS Genetics 2013. Open accessLINK [doi:10.1371/journal.pgen.1003316]

    Abstract

    The Levant is a region in the Near East with an impressive record of continuous human existence and major cultural developments since the Paleolithic period. Genetic and archeological studies present solid evidence placing the Middle East and the Arabian Peninsula as the first stepping-stone outside Africa. There is, however, little understanding of demographic changes in the Middle East, particularly the Levant, after the first Out-of-Africa expansion and how the Levantine peoples relate genetically to each other and to their neighbors. In this study we analyze more than 500,000 genome-wide SNPs in 1,341 new samples from the Levant and compare them to samples from 48 populations worldwide. Our results show recent genetic stratifications in the Levant are driven by the religious affiliations of the populations within the region. Cultural changes within the last two millennia appear to have facilitated/maintained admixture between culturally similar populations from the Levant, Arabian Peninsula, and Africa. The same cultural changes seem to have resulted in genetic isolation of other groups by limiting admixture with culturally different neighboring populations. Consequently, Levant populations today fall into two main groups: one sharing more genetic characteristics with modern-day Europeans and Central Asians, and the other with closer genetic affinities to other Middle Easterners and Africans. Finally, we identify a putative Levantine ancestral component that diverged from other Middle Easterners ~23,700–15,500 years ago during the last glacial period, and diverged from Europeans ~15,900–9,100 years ago between the last glacial warming and the start of the Neolithic.
    Take the age estimates with all the caution, as always. My own estimates suggest a quite older divergence, soon after the time of the settling of West Eurasia, what could be 40-30 Ka ago.  
    As I have said before also, modern Jews (in this case Ashkenazim but in general all Western or Hellenistic Jews from other studies academic and amateur) cluster quite strongly towards the Northern or Highlander cluster, close to Cypriots, Turks and Lebanese but far away from the Palestinians (way too diverse to be an issue of misunderstanding because of endogamy or a recent arrival from the, quite unrelated genetically, Peninsular Arabia (or any other place). Therefore the bulk of the ancestry of modern Jews does not come from ancient Palestine but some other areas further North, where we know that Judaism (and its offshoot Christianity) proselytized heavily in Antiquity. 
    Very interesting is also that the “lowlander” component is rather intensely scattered towards North and East Africa, with almost no influence in Europe and South Asia. Instead the “highlander” one has influenced especially Europe with minor influence into South Asia, as well as, to some extent, parts of North Africa (but not The Horn).

    Figure 4. Comparisons of the Levantine and Middle Eastern modal components.
    A)
    ADMIXTURE analysis based on 10 constructed ancestral components, with
    only the Levantine and Middle Eastern components highlighted. B)
    Frequency of the Middle Eastern component in world populations. C)
    Frequency of the Levantine component in world populations. Intensity of
    the colors reflects the frequency of a component in the plotted
    populations. Maps were produced using a weighted average interpolating
    algorithm, and therefore should be used as a guide rather than a precise
    representation of the frequency distribution.

    I must say, as an aside, that the terms chosen to designate the components sound horrible and imprecise, because nobody really knows for sure what Levant and Middle East mean. West Asia is a more clear and neutral nomenclature and North and South (or, as I choose, highlands and lowlands) are very descriptive, even if they overlap, especially about their likely origins in or near Kurdistan and Palestine respectively (most likely, as they are two archaeologically very rich regions in the Paleolithic as well as in the Neolithic). 
     
    18 Comments

    Posted by on March 2, 2013 in autosomal DNA, population genetics, West Asia

     

    Olive domestication origins tracked to West Asia

    Olive tree – Pelion, Greece
    (CC by Dennis Koutou)
    A new genetic study claims that the origins of olive domestication are in West Asia, more precisely at the Turkish-Syrian border (Kurdistan again?), apparently settling the doubts on whether this tree’s domestic variant may have originated either in that area, the Aegean Sea basin, Southern Iberia or North Africa, or even that many independent domestications had taken place.
    G. Besnard et al., The complex history of the olive tree: from Late Quaternary diversification of Mediterranean lineages to primary domestication in the northern Levant. Proceedings of the Royal Society B, 2013. Pay per viewLINK [doi: 10.1098/rspb.2012.2833]
    Abstract

    The location and timing of domestication of the olive tree, a key crop in Early Mediterranean societies, remain hotly debated. Here, we unravel the history of wild olives (oleasters), and then infer the primary origins of the domesticated olive. Phylogeography and Bayesian molecular dating analyses based on plastid genome profiling of 1263 oleasters and 534 cultivated genotypes reveal three main lineages of pre-Quaternary origin. Regional hotspots of plastid diversity, species distribution modelling and macrofossils support the existence of three long-term refugia; namely the Near East (including Cyprus), the Aegean area and the Strait of Gibraltar. These ancestral wild gene pools have provided the essential foundations for cultivated olive breeding. Comparison of the geographical pattern of plastid diversity between wild and cultivated olives indicates the cradle of first domestication in the northern Levant followed by dispersals across the Mediterranean basin in parallel with the expansion of civilizations and human exchanges in this part of the world.
    The study was made only on chloroplast DNA, roughly equivalent to animal mtDNA, transmitted only by the “female” line (notice that olive trees, as most plants are dioic, having both sexes and also that the preferred method of agricultural reproduction today is growing new trees from stumps, i.e. cloning). However André Berville, geneticist of the French National Institute for Agricultural Research prefers to remain cautious because, in his opinion, looking only at chloroplast DNA is not enough.
    “Pollen from the olive tree is wind-transported, so it can migrate long distances” he said. 

    Combining both types of DNA would allow researchers to understand both how local olive tree cultivation occurred and how more long-distance changes occurred, he said. 
    Secondary source: NBC News (via Pileta). 
     
    6 Comments

    Posted by on February 8, 2013 in Neolithic, plant genetics, West Asia