Jan Bartek – AncientPages.com – Yeast, a well-known ingredient for bakers and winemakers, is now being studied for its potential to trace human ancestry. Research indicates that humans began domesticating baker’s yeast as early as 7000 BCE for producing bread, beer, wine, and sake. Interestingly, wild strains of this yeast species are also found on trees.
Credit: jackmac34 – Pixabay – Public Domain
Although domesticated and wild yeasts exhibit genetic differences, researchers are investigating the potential connections between them to gain a deeper understanding of their evolutionary history.
“Other studies had just started to show that baker’s yeast in forests are different, and some of my own work in Europe had shown that the forest populations were different than the domesticated populations,” said Douda Bensasson, corresponding author of the study and an associate professor in University of Georgia’s Franklin College of Arts and Sciences Department of Plant Biology.
“But we wanted to go deeper and characterize the different groups in America and Europe.”
The study utilized publicly accessible data from global sources, along with samples of tree bark collected from various regions, with a particular focus on the southeastern United States. Notably, some samples were gathered on the University of Georgia’s North Campus near the Arch. Researchers extracted and analyzed DNA from the yeast present in these samples. This genetic information was then used to compare the yeast’s genetic composition across different regions.
“We are seeing distinct subpopulations within continents,” said Jacqueline Peña, lead author of the study and a Ph.D. candidate in UGA’s Department of Plant Biology. “And we’re seeing that, even though we had originally thought that these wild populations would be different, it seems as though they’re not completely separated from human activity.”
The understanding of how microbes such as yeast exist in their natural environments remains incomplete. Researchers have cautioned that human activities might be inadvertently causing significant environmental changes. To gather yeast samples, researchers collected pieces of tree bark and placed them into sealed tubes. They employed a method akin to winemaking to cultivate the yeast, allowing them to analyze its DNA and trace the divergence of different groups over time.
Migration During The Last Ice Age Likely Played A Key Role In Spreading Yeast
It’s highly plausible that migration during the last ice age played a significant role in the spread of yeast. As humans and animals moved across vast distances in search of more hospitable environments, they likely carried yeast with them, either intentionally or inadvertently.
This movement would have facilitated the distribution and diversification of yeast species across different regions, shaping their presence in ecosystems worldwide. Understanding this historical context can provide valuable insights into the evolutionary journey of yeast and its impact on various cultures and industries today.
“We were expecting that these would be ancient divergences and that the forest yeast would’ve had nothing to do with humans this whole time,” said Bensasson.
Credit: tombock1 – Pixabay – Public Domain
“But to our surprise, we found that it roughly coincided with the last ice age, which is around the time that humans were starting to grow their own food and spreading farming around the world.”
Peña referred to this phenomenon as a “unique duality,” highlighting the existence of both wild and domestic varieties of yeast. Despite their differences, both types have been influenced by human activity in some manner.
Yeast From The U.S. South Found In Southern Europe
Peña and Bensasson’s research into yeast from various regions revealed an intriguing discovery: yeast in the winemaking areas of southern Europe closely resembles that found in the southern United States. Their findings suggest that this yeast was transported from the U.S. to Europe over the past few centuries. The researchers attribute this to the Great French Wine Blight of the 1850s, when an insect pest inadvertently introduced to Europe caused widespread damage to vineyards. To combat this, workers imported pest-resistant vines from North America. Although these grapes were unsuitable for winemaking due to their low quality, European vines were grafted onto North American rootstock instead. This process transferred North American yeast to European vines.
This study provides valuable insights into human interactions with their environment through history. However, Bensasson expressed concerns about how such actions may be altering our world today.
See also: More Archaeology News
“If humans, without intending to, were moving microbes around thousands of years ago, just think about all the stuff that we are doing now,” said Bensasson. “We may be changing all kinds of things without knowing it. And I don’t know if that’s good or bad, but it’s a little worrying that we have no idea what we’re doing.”
The study was published in the journal Molecular Ecology
Written by Jan Bartek – AncientPages.com Staff Writer
