Monday, April 24, 2023

The real origins of grape-growing and wine-making?

It is now two decades since the first modern book appeared about the origins of wine-making, Patrick McGovern’s Ancient Wine: the Search for the Origins of Viniculture (2003), which itself came a dozen years after the first conference on The Origins and Ancient History of Wine (1991, the proceedings also being edited by McGovern). By “modern” I mean: applying to archaeological studies all of those fancy new techniques that scientists keep coming up with (often called molecular archaeology), and thus leveraging all of the new knowledge that we can now access.

This process has not slowed down since then, and, so, new publications keep appearing all the time, often challenging previous preconceptions. The histories of viticulture and viniculture work both ways — human history has led to the development of these two activities, and these activities have in turn affected human history to a great extent. The latter was, of course, especially true of classical Ancient Greece and Rome, about whose wine habits much has been written. However, previous work on the actual origins (rather than subsequent development) has focused on what Europeans call the Mid-East (although it is actually just west of the majority of the people on this planet — see: Valeriepieris: a circle housing majority of the world’s population).

This Euro-centric focus has been challenged in recent years, as I will discuss here. How did Vitis vinifera (the scientific name for the cultivated grapevine) originate from Vitis sylvestris (the wild grapevine)? After all, grapes may well have been the first plants that we domesticated!

V. vinifera (left) and V. sylvestris (right)

In the 2019 Afterword to a later edition of his book, McGovern emphasizes the ongoing rapid growth of molecular archaeology, along with other tools for the study of our ancient past. In particular, interest has focused on an understanding of how viniculture came to central and northern Europe (via southern Europe?) — we have a fairly good record of how it got from there to the so-called New World, much later. However, interest has also focused on ancient Chinese fermented beverages, which included grape wine. The history of the peoples of Central Asia is much more poorly known, to Europeans and their descendants, than that of the Near- and Mid-East.

So, our reconstructed historical scenarios can be expected to need updating. I mean, let’s face the reality of scientific procedures. Scientists start with the simplest hypothesis, and then abandon this only when forced to do so by mounting evidence (The best reason to trust science). Obviously, the simplest idea, in this case, has been that there is a single place and time for the origin of grape domestication and wine-making — sometimes called the Noah Hypothesis, as the Bible reports him to have re-planted vines only once near Mount Ararat (now in north-eastern Turkey) after the Flood.

However, it should surprise no-one that this idea is too simplistic. Grape-vines are just too widespread across Asia for people not to have stumbled across the process of grape domestication, for example, probably many many times in many many places. The only question, then, is: how many of those peoples started to carry out the process of fermentation, for instance, deliberately, rather than letting it continue to happen fortuitously? This development is, of course, in addition to those people who merely used grapes as a food source, rather than as a source of fermented beverages.

Map of the proposed scenario

The latest (2023) publication covering this topic, in detail, has 89 authors: Dual domestications and origin of traits in grapevine evolution. This follows an earlier (2019) paper by the same research group (but with only 34 authors): Whole-genome resequencing of 472 Vitis accessions for grapevine diversity and demographic history analyses.

The reason for the large number of persons involved is the amount of genome sequencing required: 3,535 “cultivated and wild grapevine accessions worldwide.” Their final conclusion, from looking at 2,237 Vitis vinifera and 949 Vitis sylvestris samples, goes like this:
In the Pleistocene, harsh climate drove the separation of wild grape ecotypes caused by continuous habitat fragmentation. Then, domestication occurred concurrently about 11,000 years ago in Western Asia and the Caucasus to yield table and wine grapevines [respectively]. The Western Asia domesticates dispersed into Europe with early farmers, introgressed with ancient wild western ecotypes, and subsequently diversified along human migration trails into muscat and unique western wine grape ancestries by the late Neolithic.
So, their idea is that our modern wine-grapes came from the Mid-East while our eating grapes came from Western Asia (the Caucasus), as depicted in the map above. Their time-line of the origin and subsequent dispersal of wild and domesticated grapevines is shown in the figure below. *

There is nothing original about this idea, as McGovern describes roughly this possibility in his 2019 Afterword. After all, it is quite likely that the initial cultivation of grapevines was for nutrients (and calories), while the development of wine-making cultivars was accidental. What we do have in this new paper, however, is a detailed quantitative confirmation of the idea; and this is what we need. The question that remains, now, is: Is this idea still too simplistic? After all, I noted above that this is the way science works: keep it as simple as possible until forced by circumstances to accept that reality is actually more complicated.

Timeline of the proposed scenario

Most of you have no direct experience of science, because your personal and professional lives are quite separate from this activity. In that case, you may well have an image of scientists as being a bunch of weirdos in white coats playing in laboratories, where they collect data, which is then fed into black-box computer analyses, and interpreted based on wild daydreams. This is often quite an accurate image, I am sorry to say, as I can attest from decades spent surrounded by professional scientists.

Many other times, of course, science is done by quite ordinary sorts of people, who proceed carefully and quietly, often “out in the field” rather than in a laboratory (ie. in a forest or an agricultural plot). The work of these latter people always seems to be more realistic, and their conclusions more convincing, at least to me.

The point here is that this new paper discussed above seems to come from the first group, not the second. Therefore, things may well change, perhaps even in the near future. We may yet find evidence for multiple independent grapevine domestications!

*  Note that we are talking mainly about red grapes here. It seems that the first evidence of cultivation of a modern white-grape variety is from what is called Late Antiquity, in this case the 8th century CE (Ancient DNA from a lost Negev Highlands desert grape reveals a Late Antiquity wine lineage).

Personal note: In honor of this post, my wife and I drank a bottle of Askaneli Brothers’ Rkatsiteli Qvevri 2020, from eastern Georgia (the Caucasus, where wine-grapes originated). This (yellowish) white wine was aged in large half-buried earthenware vessels (qvevri), just as it has been for the past five thousand years. Very different, and very interesting (and also nice wine!). This aging practice is apparently being tried elsewhere (Ancient European winemaking tradition using qvevri revived in Tasmania).

1 comment:

  1. The method is also being tried by a British Columbia winery in Canada