Cotton is actually a biotech fabric

We’re so familiar with cotton that it is easy to assume it’s a simple and basic fabric, but the version of cotton we use today has been bred by humans for thousands of years, transformed from wild shrubs into a sophisticated agricultural product. From ancient domestication to lab-grown fibers, cotton tells a story of continuous innovation.

The plant behind the fabric

Long before becoming a light summer shirt or set of sheets, cotton starts as a bushy shrub that produces short lived flowers. After the flowers die, they leave behind a fruit called a boll that houses both seeds and the protective fibers we eventually wear. Each seed is wrapped in up to 16,000 individual fibers. When a boll matures, it bursts open, exposing the cotton to air, which dries it out and makes it possible to harvest.

There are about 50 known cotton species, and four were independently domesticated by humans. The most common, Gossypium hirustum, accounts for about 90% of global production. G. barbadense, also known as Pima or Egyptian cotton, produces longer, silkier fibers and is used for higher end textiles.

Today, cotton is grown in around 70 countries, though half of global production comes from three: the United States, India, and China. Unfortunately, cotton farming carries a heavy environmental footprint, famous for its high water use and extensive pesticide application.

Cotton as a commodity

Cotton’s expansion as a dominant global commodity was a complex process involving technological innovations, industrial development, trade networks and labor systems.

Key developments like Eli Whitney’s cotton gin in 1793 made processing of the cotton variety most common in the southern United States more efficient. This transformation had major and often devastating impacts, including the expansion of slave labor in the American South, and exploitation that continues in various forms today in cotton farming and production facilities worldwide.

Currently, cotton accounts for 23% of global fiber production for textiles, making it the second most common textile fiber after polyester. Its popularity stems from its versatility. It can be woven or knitted into everything from t-shirts to denim, and is comfortable, washable, dyeable, and affordable.

Seven thousand years of breeding

The earliest archeological evidence of domestic cotton was found at the Neolithic site of Mehrgarh on the Kachi Plains of Pakistan, dating from 7,000 years ago — around the time the pyramids were being built. Cotton was also independently domesticated in Mesoamerica and Peru.

Like the difference between wild and domesticated animals, wild cotton looks and behaves very differently from domesticated cotton. It naturally grows as a perennial plant that’s photoperiod sensitive, only flowering when day length reaches a certain threshold. Through selective breeding, humans have transformed cotton into a short, compact annual shrub that doesn’t rely on daylight cues for flowering.

This is biotechnology in the broad sense: human guided manipulation of genetic diversity to create desired traits.

Modern cotton breeding began in the late 19th and early 20th centuries, with selection focused on longer fibers, disease and pest resistance, drought and heat tolerance, and higher yields. By the 1950s, systematic selection and hybridization were being used to produce region-specific cultivars. This is biotechnology in the broad sense: human guided manipulation of genetic diversity to create desired traits.

The mixed blessing of genetic engineering

The 1990s brought the introduction of Bt cotton, genetically engineered to produce its own insecticide. Named for the bacterium Bacillus thuringiensis, Bt cotton creates proteins toxic to pests like bollworm, reducing the need for chemical pesticides while increasing yields for farmers.

The outcomes of this have been complicated. On the positive side, Bt cotton reduces crop loss and pesticide use. On the negative side, there are concerns about inequality in seed access. Despite these challenges, genetic engineering has become dominant: over 80% of global cotton production (25.4 million of 31.6 million hectares) comes from genetically engineered plants.

Completely organic cotton exists, but represents less than 1% of total production. It is expensive to produce and has its own issues, including difficulty in supply chain tracking. The economic and practical advantages of engineered cotton make it unlikely that organic will gain significant market share.

The future

Cotton innovation is continuing with more sophisticated breeding for pest resistance and environmental adaptation.

Companies like Vreseis have been using classical breeding programs to enhance cotton’s natural colours (browns, greens and other hues) to reduce the need for chemical dyes in textile production. Meanwhile, Galy, a biotech company, is attempting to cultivate cotton using cell culture - growing cotton fibers in the lab instead of in the field. While economically and technically challenging, the company raised $33 million in Series B funding in 2024, with backing from the Gates Foundation’s Breakthrough Energy, H&M, and Inditex, the owner of Zara.

Cotton demonstrates that the line between traditional agriculture and biotechnology is far blurrier than we often assume. From millennia of selective breeding to decades of genetic engineering and a range of future developments and applications, biotech and cotton are irreversibly intertwined.

Learn more about the evolution of cotton domestication at the Wendel Lab, Iowa State University