Scientists have unearthed more information on the origins of wine, using genomics to discover that grapevines were first domesticated simultaneously in two separate regions of the world around 11,000 years ago
The earliest archaeological evidence for viticulture and wine drinking was unearthed around 8,000 years ago in the Caucasus, but the origin of grapevine domestication has remained mysterious, until now. Using genomics, scientists report that grapevines were first domesticated simultaneously in two separate geographic regions shortly after the glaciers retreated around 11,000 years ago. At this time, it appears that Neolithic farmers began cultivating the best vines with the biggest, juiciest grapes.
To learn more about the route that domesticated grapevines followed, a genomic analysis of grapevine varieties was conducted by an extremely large and varied international scientific collaboration (89 scientists!!) from 23 institutions across 17 countries. This research, which was primarily conducted during the pandemic lockdown, identified two separate domestication events for grapes that led to their use in winemaking. According to the data, these domestication events occurred more or less simultaneously, about 1000 km (620 mi) apart in Western Asia (the Levant [CG1, for ‘cultivated grape 1’]; modern day Israel, Palestine, Lebanon and Jordan) and the south Caucasus ([CG2]; modern day Georgia, Armenia and Azerbaijan) (Figure 1). These separate grapevine domestication events coincide with the development of agricultural farming as well as with the domestication of table grapes.
The researchers began their work by sequencing the genome of wild V. sylvestris, from Tunisia, to act as their reference. They then sequenced genomes of an additional 3,186 different grapevine varieties obtained from scientific collections, including 2,237 samples from domesticated wine grapes and 949 wild grapes. The researchers also included genomic data from 339 previously sequenced grapevines, including data from 73 wild grapes. Of this group, 2,448 genomes were unique, including 844 from wild vines. The analysis also revealed previously undocumented domesticated grape cultivars lurking in old vineyards, which their discoverers named.
Comparisons of the grapes’ genomic differences and similarities allowed the researchers to trace the grapevines’ family tree and piece together their domestication history and early geographical journey. According to these data, all modern varieties of grapes appear to have originated from an ancient wild grape that lived across much of Eurasia and North Africa for the past 400,000 years.
Comparisons and analyses of these genomic sequences found that wild grapevines could be lumped into four groups whereas domesticated grapevines formed six distinct groups (west Asian table grapes, Caucasian wine grapes, Muscat table and wine grapes, Balkan wine grapes, Iberian wine grapes and western European wine grapes).
Previous archaeological studies suggested that the CG2 grapevines were the first to be domesticated, and these gave rise to grape varieties that migrated with the Neolithic spread of agriculture throughout Europe. However, this study indicates that CG2 cultivars were mainly confined to the Caucasus Mountains, and contributed little to domesticated grapevine diversification.
In contrast, this study shows that CG1 grapevines from the Levant, which initially provided table grapes instead of wine grapes, had a tremendous influence over the development of modern grapevines. These grapevines moved through the Inner Asian Mountain Corridor (a journey followed by other food crops) and spread eastward through central Asia into India and China, north to the Caucasus and over the Zagros mountains, and then traveled northwest through Anatolia to the Balkans. At the same time, grapevines also spread westward across the north African coastline. Most significantly for wine, they also travelled to Iberia and Western Europe.
Most modern grapevines descended from just four ancient cultivars from Europe and one from the Caucasus, and domesticated grapevines were hybridized with their wild cousins to make them more suitable for wine production. As any wine drinker knows, there are many varieties of grapevines — merlot, cabernet sauvignon, pinot noir — but they all belong to one domesticated species, Vitis vinifera.
“We care about this grape so much we gave each variety a specific name”, senior author of the study, evolutionary biologist Wei Chen, a senior research scientist at Yunnan Agricultural University, pointed out in a media briefing. “We don’t do it for, like, wheat or barley.”
According to the study authors, communities began to trade ‘superior grapevine cultivars along trade routes’, sharing not only their seeds but also their skills and knowledge. Further, this study supports previous archaeological evidence that the development of agriculture was accompanied by (and possibly motivated by) fermented beverages.
“The grapevine was probably the first fruit crop domesticated by humans”, Dr Chen said.
“It was one of the first globally traded goods”, added a co-author of the study, plant biologist Peter Nick, a professor of botany at Karlsruhe Institute of Technology. “It’s justified to say that the domestication of grapevines was really one of the driving forces of civilization.”
Further, despite domestication, there still are wild grapes out there. Although those ancestral grapevines produce small bitter grapes, they are valuable to modern wine producers.
“These wild grapes and these very old varieties still have these resilience genes, which we will need to render the grape resistance against the challenge of climate change.”
Yang Dong, Shengchang Duan, Qiuju Xia, Zhenchang Liang, Xiao Dong, et al., (2023). Dual domestications and origin of traits in grapevine evolution, Science 379(6635):892-901 | doi:10.1126/science.add8655