Artificial selection is a process in which humans selectively breed plants to enhance desirable traits such as higher yield, disease resistance, improved taste, and larger size. Over centuries, this practice has transformed many wild plants into the crops we rely on today.
Unlike natural selection, which occurs due to environmental pressures, artificial selection is guided by human preference. This has led to the evolution of new plant varieties that are often very different from their wild ancestors.
Some of the most commonly cultivated crops, including corn, wheat, bananas, and tomatoes, have undergone extensive artificial selection. This topic explores examples of artificially selected plants, their history, and their impact on agriculture and society.
1. Corn (Zea mays): From Teosinte to Modern Maize
Origins and Evolution
Corn, also known as maize, is one of the most well-known examples of a plant shaped by artificial selection. It originated from a wild grass called teosinte, which had small, hard kernels and was nearly inedible.
Ancient farmers in Mesoamerica selectively bred teosinte over thousands of years to produce larger ears with soft, edible kernels. Today’s corn is vastly different from its wild ancestor and is cultivated worldwide for food, animal feed, and biofuel production.
Key Traits Improved Through Artificial Selection
- Larger kernels with higher starch content.
- More rows of kernels per cob for increased yield.
- Softer, non-shattering kernels that remain on the cob.
- Greater resistance to pests and diseases.
Corn is now one of the most important staple crops, feeding billions of people globally.
2. Wheat (Triticum spp.): The Backbone of Civilization
Transformation Through Selective Breeding
Ancient wheat varieties, such as einkorn and emmer wheat, had brittle seed heads that shattered easily, making harvesting difficult. Farmers selected plants with stronger, non-shattering seed heads, leading to the development of modern wheat varieties.
Artificial selection has allowed wheat to become a high-yield, drought-resistant crop that supports global food production.
Key Traits Improved Through Artificial Selection
- Larger grains with higher nutritional value.
- Stronger stalks to prevent lodging (falling over).
- Shorter growth cycles for faster harvests.
- Increased gluten content for better bread-making properties.
Today, wheat is a staple food for billions of people and is used to make bread, pasta, and other essential foods.
3. Bananas (Musa spp.): From Seeds to Seedless
The Shift from Wild Bananas
Wild bananas were small, full of large seeds, and difficult to eat. Through centuries of artificial selection, farmers cultivated seedless, sweet bananas that are easy to peel and consume.
Most modern bananas come from the Cavendish variety, which is genetically uniform due to clonal propagation. While artificial selection has made bananas more convenient, it has also made them more vulnerable to diseases, as they lack genetic diversity.
Key Traits Improved Through Artificial Selection
- Larger, sweeter fruit with soft flesh.
- Seedless varieties for easier consumption.
- Stronger plant resistance to pests and environmental changes.
- Thicker skin for better transportation and storage.
Bananas are now a major global crop, providing essential nutrition worldwide.
4. Tomatoes (Solanum lycopersicum): From Wild Berries to Juicy Fruits
The Domestication of Tomatoes
Wild tomatoes were small, sour, and had thick skins. Early farmers in South America selectively bred them for larger size, improved taste, and softer skin.
Modern tomatoes are available in various shapes, colors, and flavors, from cherry tomatoes to large beefsteak varieties. Selective breeding has also improved disease resistance and shelf life.
Key Traits Improved Through Artificial Selection
- Larger fruit size for better market value.
- Sweeter taste for improved flavor.
- Uniform ripening for easier harvesting.
- Longer shelf life to reduce spoilage.
Tomatoes are now a key ingredient in global cuisines, used in sauces, salads, and countless dishes.
5. Carrots (Daucus carota): From Bitter Purple Roots to Sweet Orange
The Evolution of Carrots
Wild carrots were small, purple, and bitter, primarily grown for medicinal purposes. Over time, farmers selectively bred carrots for larger, sweeter, and more colorful roots.
The modern orange carrot was developed in the Netherlands in the 17th century, becoming the globally recognized variety today.
Key Traits Improved Through Artificial Selection
- Sweeter taste for better consumption.
- Larger root size for increased yield.
- Orange color due to high beta-carotene content (Vitamin A).
- Smoother texture for easier cooking.
Carrots are now an important vegetable, providing essential nutrients in diets worldwide.
6. Broccoli, Cauliflower, and Cabbage: The Power of Selective Breeding
One Species, Multiple Vegetables
Broccoli, cauliflower, cabbage, kale, and Brussels sprouts all come from the same wild plant species: Brassica oleracea.
Through selective breeding, farmers emphasized different traits:
- Broccoli – Developed for large flower heads.
- Cauliflower – Selected for compact, edible flower clusters.
- Cabbage – Grown for large, leafy heads.
- Kale – Cultivated for tender, nutritious leaves.
Key Traits Improved Through Artificial Selection
- Different growth forms to suit various culinary uses.
- Higher nutritional content with increased vitamins and minerals.
- Greater disease and pest resistance.
These vegetables have become essential components of healthy diets worldwide.
7. Apples (Malus domestica): From Wild Crabapples to Crisp Delights
How Apples Were Transformed
Wild apples were small, sour, and tough, similar to modern crabapples. Farmers selectively bred them for larger size, sweeter taste, and better storage ability.
Today, there are over 7,500 apple varieties, each with unique flavors and textures.
Key Traits Improved Through Artificial Selection
- Sweeter taste for fresh consumption.
- Larger fruit size for commercial appeal.
- Better shelf life for global distribution.
- Improved disease resistance.
Apples are now a widely consumed fruit, enjoyed fresh, dried, or in juices and desserts.
The Impact of Artificial Selection on Agriculture
Artificial selection has revolutionized agriculture, allowing humans to:
- Produce more food to support growing populations.
- Improve plant resilience against diseases and climate change.
- Enhance nutritional value to provide healthier diets.
- Increase commercial viability of crops through better taste, texture, and shelf life.
However, artificial selection also has drawbacks, such as:
- Loss of genetic diversity, making plants more vulnerable to pests and diseases.
- Dependence on human intervention, requiring ongoing breeding efforts.
- Environmental impact, as high-yield crops may require more resources.
Plants that have undergone artificial selection have transformed global agriculture, food supply, and diets. From corn and wheat to bananas and tomatoes, humans have shaped plants to meet their needs.
While artificial selection has led to improved crops, maintaining genetic diversity and sustainable farming practices is essential for future food security. Understanding how selective breeding works helps us appreciate the rich history behind the food we eat today.