Mankind has been experimenting with the food we grow almost as long as we have had agriculture. The ancient Mayan civilization, for example, grew hybrid corn. And now, with advances in technology, we are able to make changes to the genetic makeup of the plant itself.

Here is a primer on three of the most common ways we alter the plants we eat.

  1. GMOs

GMO stands for genetically modified organism. It is used to describe any organism whose genetic material has been changed through genetic engineering. They have been used to manufacture drugs and genetically modified foods.

The genetic modification can take the form of gene mutation, inserting genes from another organism, or eliminating genes. There are several ways that genes can be introduced from other organisms. One way is by attaching the gene to a virus. Another way is to insert DNA into the cell nucleus using a syringe, and another is using an electric pulse to insert new genes.

Genetically modified crops are plants where the DNA has been changed, usually to add a new trait to the plant that does not exist naturally. The new trait could be a greater resistance to disease, or insects, or cold weather, or certain herbicides, or higher nutritional value.

There is a great deal of controversy surrounding GMO foods. Many people are concerned that there still is not enough information about these types of foods, their risks, and their effects on human health, even though they are already being consumed by people.  There is general agreement among scientists that genetically modified foods are no more dangerous than regular food, but that each new form needs to be tested before being added to the food supply.

  1. Heirloom seeds

This is a natural way of improving a plant. These seeds are the result of selecting the best ones generation after generation. For example, you are growing some tomato plants. Some grow larger and tastier than others. So, you take the seeds from these larger plants and use them to grow a second generation of plants. Then you do the same thing again – choose the seeds from the best plants of the second generation and plant them.

These seeds – the best-of-the-best selected each generation and passed down – are called heirloom seeds. They often produce foods that are tastier and more resistant to pests. Today, these types of seeds are grown on smaller farms, where growers take the time to collect the best seeds.

  1. Hybrids

A hybrid plant is the result of cross-pollination between two different species of plants, which is done by humans.

This can be done on a small or large scale. However, commercial hybrid seeds are not the most reliable. They initially produce good hybrid plants, but the seeds from those plants are often unpredictable. As a result, farmers need to buy new hybrid seeds each year for planting.

Humans – such as the Mayans –  have practiced hybridization for centuries.