Wednesday, August 9, 2023

The spread of vitis vinifera in Western Eurasia

Dong, et al., shocked the wine world by providing genetic evidence of two separate, simultaneous domestications of vitis sylvestris, one in the Caucasus and the other in the Levant. I have described the study methodology and findings in previous posts

I have also written on the methodologies employed by the authors in attempting to answer questions regarding: (i) the diversification history of European wine grapevines and (ii) "when and how distinct grapevine ancestors formed in Europe with relevance to Syl-W introgressions." In this post I illustrate the vehicle and routes for grapevine distribution in Europe and North Africa.

Vehicle for Grapevine Spread
The Agricultural Revolution refers to the switch from hunting and gathering as the main methods of food production to the more sedentary domestication and husbanding of plants and animals. The revolution was characterized by domestication of wild flora and fauna and distribution between the original point of production and outlying areas either by migration or cultural exchange.

In the case of Eurasia and North Africa, “Neolithization” occurred when agricultural innovations developed in the Fertile Crescent were distributed to all points of the horizon on the backs of migrating agriculturists. The chart below illustrates the impetus and dispersal directions in the early part of the West-Asian-origin Agricultural Revolution.


Europe
The chart below shows the major population movements in Europe over the last 50,000 years. Hunter-gatherers who had moved south to escape the Ice Age had repopulated the continent, albeit with low-density groups.


This situation changed approximately 8500 years ago when " a wave of populations from the Middle East entered Europe via Anatolia." This migration wave spread farming practices into the region, "initiating the Neolithic Revolution in Europe."

These Anatolian-sourced farmers made their way into Europe via two routes: (i) a northern route across Central Europe and (ii) a westward route along the Mediterranean coast. The routes are illustrated graphically on the map below. The map also shows the ETA of agriculture for selected regions.


North Africa
According to Simōes, et al., the human population in North Africa had exhibited genetic continuity since the Upper Paleolithic, a period of isolation interrupted by the entry of European Early-Neolithic farmers. A study of genes retrieved from remains at a North African site, referred to as KTG, reveals that these European farmers were descendants of the Anatolian farmers who had spread to Europe by way of the Mediterranean route, eventually reaching the Iberian Peninsula.

These migrants travelled to Morocco around 5500 BCE bringing with them new ways of life, farming practices, domestication traditions, and pottery traditions, all of which were adopted by the indigenous populace. 

A second group of genes show up in the profile of the Moroccan populace. This new migratory group is thought to be descendants of the pastoralists who had exited the Fertile Crescent and crossed the Sinai, traveling along the African Mediterranean coast and arriving in Morocco 1000 years after the descendants of the Anatolian-origin farmers.

Grapevine Distribution
The cultivar CG1, a table grape, made its way out of its domestication center north towards Anatolia and west towards North Africa (for the purposes of this post). Somewhere within the domestication center, or within Anatolia, there was a significant introgression of Syl-W genes into CG1. Shortly thereafter, the Muscat cultivar split off from CG1. The new ancestor variant -- CG3 in the figure below — was used both as a table grape and a wine grape.


As the Anatolian farmers traversed Europe in search of new agricultural land, they carried the CG1 cultivar along with them and it interacted with Syl-W variants along the way to form new ancestor-cultivars in the Balkans, the Iberian Peninsula, and Western France (called the Western European ancestor in the below chart).

Dong, et al., identifies the Moroccan vitis vinifera as being inconsistent with a cultivar that travelled through Europe and then crossed over to Morocco. The vines did not exhibit the shared introgression from Syl-W that all European grapes possess. The Moroccan vines would have transited Africa with the descendants of the Levant-origin migrants, finally bringing vinous relief to the inhabitants 1000 years after it was available just across the strait.

The characteristics of the grapes distributed across Europe are as indicated in the table below.

Ancestry Group

Grape

Date of Split from CG1

Syl-W introgression

CG3

Muscat

10,500 years ago

11.4 - 18% ancient

CG4

Balkan Wine

8070 years ago

ditto

CG5

Iberian Wine

7740 years ago

ditto

CG6

Western European Wine

6910 years ago

ditto + 25 - 30% more recent Syl-W introgression


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I will continue the series with discussions of the distribution of vitis vinifera north into the Caucasus and east into Iran in upcoming posts.

Bibliography
EurekaAlert, Human Mobility and Western Asia’s early State-level societies, Max Planck Institute of Geoanthropology, 5/26/20.
D. Baird, et al., Agricultural origins on the Anatolian Plateau, 3/9/18.
Jan Bartek, Genomics and Archaeology Rewrite the Neolithic Revolution in the Maghreb, ancient pages.com, 6/28/2023.
B. Bramanti, et al., Genetic Discontinuity Between Local Hunter-Gatherers and Central Europe’s First Farmers, science, Vol 326, Issue 5949, 3 Sept 2009.
Muhal Feldman, et al., Late Pleistocene human genome suggests a local origin for the first farmers of central Anatolia, Nature Communications, 10 (1258), 2019.
Iosif Lazaridis, et al., Genomic insights into the origin of farming in the ancient Near East, Nature 536, 2016.
Iosif Lazaridis, et al., Ancient DNA from Mesopotamia suggests distinct Pre-Pottery and Pottery Neolithic migrations into Anatolia, Science 377, 6609, 25 Aug, 2022.
Fernando Racimo, et al., The spatiotemporal spread of human migrations during the European Holocene, PNAS, April 2020.
Luciana G. Simōes, et al., Northwest African Neolithic initiated by migrants from Iberia and Levant, Nature, 618, 6/-6/23.
Laura Spinney, When the First Farmers Arrived in Europe, Inequality Evolved, Scientific American, 7/1/2020.


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