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Nature under the influence
Nature under the influence • By Charles Prémont
We often tend to think that species evolve without any influence from humankind. In fact the opposite is true: since many of our actions alter the environment, they necessarily also affect the way plants and animals adapt to these changes. Humans have also forced different plants to reproduce with each other so as to create new ones. Here we describe two examples of human impacts on the evolutionary process.
Selection and hybridization
Photo Rashid Valitov/Shutterstock.com
People have been selecting plants since time immemorial, and especially since the birth of agriculture. By choosing specimens with the most attractive characteristics (size of their fruit or ears, yield, height, etc.), growers slowly but surely transformed certain plants to meet their needs.
In the late 19th century, we began using a technique we call hybridization. By breeding two plants from different varieties, subspecies, species or even genera, we have sought to create a hybrid combining their most desirable features. This technique has allowed us to improve plants’ yield, taste, protein content or storage time, depending on their intended use. We can also try to create trees and other plants with greater climate, disease and pest resistance. Hybridization has been used to produce many cultivars of corn, for instance, but also fruit like ‘Empire’ apples, a cross between ‘McIntosh’ and ‘Red Delicious’ varieties, or tangelos, combining mandarin oranges and grapefruit, and triticale, a cross between wheat and rye. This technique has proved very useful in horticulture, too, for transforming many ornamental plants like orchids, begonias and roses. When it comes to these plants, hybridization is so common that it’s not unusual to find plants resulting from multiple hybridizations.
← Triticale is a cross between wheat and rye.
