 |
| Various types of contemporary tomato species (Source: University of Georgia/Alexis Ramos) |
Paleobotanists and archaeologists concerned with agriculture know quite a bit about the origins of agriculture. For the vast amount of information that is known there are countless questions that remain unanswered. There are generally accepted trends within domestication, but the specifics concerning individual domesticates may not be precisely known. A combination of multiple lines of evidence are helping answer several of these questions, leading to a greater knowledge pool that can be used to not only understand the past but better resolve matters in the present and prepare for a riper future. Today’s blog post will discuss the latest advancements in knowledge concerning the origins of one of the world’s favorite vegetables: tomatoes.
Tomatoes are a popular vegetable (although they are technically a fruit) grown and used worldwide. It has become a dietary staple in various cuisines, as well as is considered an essential component in some cultural dishes (e.g., Italian foods). Tomatoes are perennial plants, meaning they come back every year, but they often act like an annual plant, one that needs to be replanted each growing cycle. This is because while tomatoes can and are grown worldwide, they are particularly sensitive to their environmental conditions. Too dry or too cold an environment leads to the death of the plants, requiring a new crop to be planted.
Much of the variability in growing tomatoes has been credited to their origins, which have never been precisely known or understood. It was clear from historical evidence that tomatoes were a New World plant. Spanish Conquistadors encountered tomatoes when they came to Central and South America, eventually bringing it to the Old World, specifically Europe. But where specifically in the Americas the domestication of tomatoes began was unclear. Historical, biological, and linguistic (yes, you read that right!) led to two competing hypotheses concerning the origins of the domesticated tomato: one camp believed it was of Central American, specifically Mexican, origin, whereas the other camp was certain it was a South American, precisely Ecuadorian, domesticate.
In 2012 the answers began to bear fruit. This was the year the first domesticated tomato species was fully genetically sequenced, which was followed by the sequencing of various other species. From these early studies more information concerning the process of the domestication became clear. It had always been hypothesized that tomato domestication was a two step process: first in increasing the tomato size from that of a blueberry to cherry sized, followed by artificial selection in size and physical appearance variations. This was confirmed through the genetic analyses. What was unexpected, however, was the additional information concerning this two step process. It appears that tomato domestication did not occur in one location but in two! Much like with maize domestication it appears tomato domestication occurred in both Central and South America. While archaeological evidence is scant it appears that people in both locations traded the plants, and as they worked to domesticate it continued to trade and incorporate their artificial selection methods to the creation of the world’s most beloved vegetable/fruit.
Genetic analyses are ongoing to further understand how specifically the domestication occurred, and hopefully with more archaeological study supporting evidence will be discovered and provided to back up the genetic data. At this time, however, scholars are excited about what they have learned as it not only enhances our current understanding of tomato domestication, but this information can be useful in furthering the robusticity of this domesticate for future generations.
Bibliography
Denham, T. (2014). Tomatoes: Origins and Development. Encyclopedia of Global Archaeology, 7316–7319.
Razifard, H., Ramos, A., Della Valle, A. L., Bodary, C., Goetz, E., Manser, E. J., ... & Caicedo, A. L. (2020). Genomic evidence for complex domestication history of the cultivated tomato in Latin America. Molecular biology and evolution, 37(4), 1118-1132.
Oxford University Press. "Evolution on the vine: A history of tomato domestication in Latin America." Phys.org 7 January 2020. Electronic.
Universitat Politècnica de València. "Tomato domestication involved agricultural societies from Peru to Mexico." Phys.org 1 March 2022. Electronic.
4 comments:
It is interesting that the research on tomatoes is in progress. The unique position the tomato has, due to its lack of archaeological evidence, makes it fascinating to read about. It is not too surprising that the hypotheses had to draw upon many different aspects of the tomato beyond archaeology. I am shocked about linguistics being used for the hypotheses. Because maize and tomatoes share similarities in their origin in domestication occurring in Central America and South America, does that mean that tomatoes were possibly domesticated in stages similar to maize?
-Maxwell Black
Interesting question, Maxwell. At this time I cannot say if tomatoes went through stages of domestication similar to maize. That conclusion was reached in part due to the physical evidence of maize in different locations and the genetic differences present among the cobs. I hope that further genetic study can provide us more information.
I was unaware that the domestication of tomatoes involved a two-step process, which entailed an initial increase in size followed by deliberate selection for specific qualities through artificial means. What was particularly remarkable for me was that the genetic data indicates that it did not happen in just one place, but rather in both Central and South America.
It was so interesting to learn that tomatoes were a New World plant, brought to Europe by Spanish Conquistadors, but the specific location of domestication in the Americas remains unclear.
-Ahmesha Johnson
Post a Comment