Selective breeding, also known as artificial selection, is a process used by humans to develop new organisms with desirable characteristics. In selective breeding, a breeder chooses two parents with beneficial phenotypic traits to reproduce, yielding offspring with those desired traits.
Selective breeding can be used to produce tastier fruits and vegetables, crops with greater resistance to pests, and larger animals that can be used for meat. In fact, selective breeding is one of the earliest forms of biotechnology, and it's responsible for many of the plants and animals that we know today.
One of the earliest examples of selective breeding is the domestic dog Canis familiaris , which humans have been breeding for at least 14, years. Scientists believe that the domestic dog evolved from the wild gray wolf Canis lupus , and through artificial selection, humans were able to create hundreds of different dog breeds.
As people domesticated and bred dogs over time, they favored specific traits, like size or intelligence, for certain tasks, such as hunting, shepherding, or companionship. As a result, many dog breeds have vastly different appearances. Think of the Chihuahua and the Dalmatian — they're both dogs, but they share few physical attributes. This degree of difference in a single species is a unique phenomenon in the animal world.
Selective breeding has also been practiced in agriculture for thousands of years. Almost every fruit and vegetable eaten today is a product of artificial selection. Cabbage, broccoli, cauliflower, Brussels sprouts, and kale are all vegetables derived from the same plant, Brassica oleracea , also known as wild cabbage. By isolating wild cabbage plants with specific characteristics, farmers were able to create a variety of vegetables from a single source, each with different flavors and textures.
Broccoli, for example, was developed from wild cabbage plants that had enlarged flower development while kale was derived from Brassica oleracea with larger leaves. Corn, or maize, is an unusual product of selective breeding.
Unlike rice, wheat, and cabbage, which have clear ancestors, there is no wild plant that looks like corn. The earliest records of maize indicate that the plant was developed in southern Mexico 6,, years ago from a grass called teosinte.
Scientists believe that early farmers selected only the largest and tastiest kernels of teosinte for planting, rejecting punier kernels. This process allowed the farmers to develop corn very quickly, as small changes in the plant's genetic makeup had dramatic effects on the grain's taste and size.
Despite their physical dissimilarities, teosinte and corn only differ by about five genes. Today, corn is a staple in diets across the world. Averaged over the years from to , million tons of maize was produced each year around the world, primarily in the United States, China, and Brazil. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.
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If no button appears, you cannot download or save the media. Text on this page is printable and can be used according to our Terms of Service. Any interactives on this page can only be played while you are visiting our website. You cannot download interactives. In the mids, Charles Darwin famously described variation in the anatomy of finches from the Galapagos Islands.
Alfred Russel Wallace noted the similarities and differences between nearby species and those separated by natural boundaries in the Amazon and Indonesia. Independently they came to the same conclusion: over generations, natural selection of inherited traits could give rise to new species.
Use the resources below to teach the theory of evolution in your classroom. Natural selection is the process through which species adapt to their environments. It is the engine that drives evolution. Charles Darwin and Alfred Wallace developed the idea of evolution through natural selection.
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