Author : Wahid Ahmad
Maize, also known as Indian corn, is a crucial staple crop, remaining the most
important food crop in the Americas with over 150 varieties for different
purposes. With a global production of about a billion tons annually, maize is
undeniably one of the world's most important crops.
The history of maize domestication has been a topic of debate within
archaeology. Welcome to Anthromedia. In this video, we will trace the history
of maize domestication. Before we proceed don’t forget to Subscribe.
The first plant domestication in the Americas started in humid tropical
forests, evolving from small house gardens around 10200 to 7600 years ago in
northern South America and Panama. This early horticulture transformed into
slash-and-burn farming over 5000 years, with extensive forest clearance by 5000
to 4000 BC. Squashes, leren, and bottle gourds were likely the initial
domesticates, with gourds dating back to 8000 BC.
Maize, or corn, was a crucial part of life for many Native Americans when
Christopher Columbus arrived in the Americas. It was grown extensively across a
vast region from Argentina and Chile to Canada, thriving in diverse
environments like swamps and arid lands. Over time, different varieties of
domesticated maize evolved to adapt to local conditions.
From teosinte
to maize
The ancestor
of maize, Zea mexicana, originated in Mesoamerica as teosinte. The
transformation from wild teosinte to primitive corn likely occurred between
13000 and 6000 BC due to a mutation in the teosinte gene proposed by botanist
George Beadle. This mutation made the fruit cases softer, leading to the
development of domesticated maize.
Differences between teosinte and maize include long branches with tassels in
teosinte and short branches with ears in maize. The gene tb1 controls this
distinction, and changes in its regulatory regions played a role in the
transition.
A commonly accepted hypothetical scenario for maize domestication suggests it
might have started unintentionally during the gathering of wild teosinte.
Selective pressure for harvestable types of teosinte with shrunken spikes or
bunches may have led to their establishment near campsites. Humans, over time,
would have started deliberately planting the more useful types and removing
weeds, gradually evolving teosinte towards maize. The crucial stage in
domestication was when people began selectively harvesting and planting
transitional forms of teosinte, changing its reproductive strategy to depend on
human intervention.
Origin
The transformation of
teosinte into maize is believed to have taken many centuries and likely
occurred in southwestern Mexico, specifically in the deciduous forests of the
Balsas Valley region. The domestication process involved selecting seeds with
preferred traits and rejecting less desirable ones.
Some researchers think maize might have originally come from tropical lowlands
where there weren't many wild plant foods. Early on, maize would have been a
better source of calories than the plants in the wild forests. Human
populations settled around numerous lakes in the Central Balsas Valley after
the Ice Age during warmer and humid conditions. By about 6000 BC, people were
cultivating maize and squash in this region. By 5600 BC, maize had spread into
southern Central America, and by 5000 to 4000 BC, it was found in Columbian
valleys further south.
The Guilá Naquitz Cave in Oaxaca provided a date of 4250 BC for maize, and
there is indirect evidence of even earlier maize cultivation before 5000 BC.
In southern Mexico, the Tehuacán Valley is like a history book about how people
first started growing corn in dry environments. Initially, people in this
region relied on hunting and collecting wild foods, but as the game population
declined around 8000 BC, they shifted to a more intensive gathering of wild
plant foods. By at least 4500 BC, the majority of the diet consisted of
tropical grasses, cacti, and maguey. This shift likely prompted some form of
cultivation or domestication of native plants, marking a crucial step in the
development of maize agriculture.
After 2500 BC, there was an increase in crop yields in Mesoamerica. People
started growing foods like beans, amaranth, gourds, and maize that could be
stored to endure lean months. They lived in larger, more permanent settlements
and used well-made grindstones to process their smaller maize, which resembled
teosinte.
These sedentary villages replaced earlier nomadic patterns. The communities had
ample storage, enabling them to survive through periods of scarcity. Similar
cultural developments were observed in dry caves across northern Mesoamerica.
Highland lakes in the Valley of Mexico and elsewhere likely supported settled
communities experimenting with crops like amaranth.
In the Tehuacán Valley, they found a ton of old corn pieces—more than 24,000!
These pieces show how corn changed over time. The earliest ones were really
small and couldn't spread their seeds naturally, indicating domestication
around 2700 to 2600 BC. By 2000 BC, people all over were starting to rely at
least a bit on growing their own food. A thousand years later, in the Mexican
lowlands, we see the first signs of organized societies.
The Columbian Exchange refers to the exchange of disease, food, ideas, and people
between the Americas and Europe, Africa, and Asia in the 15th and 16th
centuries. Maize, along with other vital crops like potatoes, sweet potatoes,
and cassava, was introduced to Europe during this period. Maize was already
cultivated in the Americas from Canada to Chile, but its widespread
introduction to the Old World occurred after Columbus's voyages. Maize became a
significant crop in Europe, including the UK, where its cultivation has
increased significantly since the 1970s, serving various purposes such as
livestock feed, game cover, and energy crops for anaerobic digesters.