Artificial Selection in Animals

The "Labradoodle" is a product of artificial selection. Getty/Ragnar Schmuck

Artificial selection is mating two particular individuals within a species that possess the traits desired for the offspring. Unlike natural selection, artificial selection is not at all random and is controlled by the desires of humans. Animals, both domesticated and wild animals that are now in captivity are often subjected to artificial selection by humans to get the ideal pet in looks, demeanor, or a combination of both.

Artificial selection is not a new practice. In fact, Charles Darwin, the father of evolution, used artificial selection to help bolster his data and work as he came up with the idea of natural selection and the Theory of Evolution. After traveling on the HMS Beagle to South America and, perhaps most notably, the Galapagos islands where he observed finches with different shaped beaks, Darwin needed to see if he could reproduce these types of changes in captivity.

Upon his return to England after his voyage, Darwin bred birds. Through artificial selection over several generations, Darwin was able to create offspring with desired traits by mating parents who possessed those traits. Artificial selection in birds could include color, beak shape and length, size, and more.

Artificial selection in animals can actually be a very profitable endeavor. For instance, many owners and trainers will pay top dollar for a race horse with a particular pedigree. Champion racehorses, after they retire, are often used to breed the next generation of winners. Musculature, size, and even bone structure are traits that can be passed down from parent to offspring. If two parents can be found with the desired race horse characteristics, there is an even greater chance that the offspring will also have those championship traits that owners and trainers desire.

A very common example of artificial selection in animals is dog breeding. Much like breeding championship race horses, there are particular traits that are desirable in different breeds of dogs that compete in dog shows. The judges will look at coat coloring and patterns, behavior, and even teeth. While behaviors can be trained, there is also evidence that some behavioral traits are passed down genetically as well.

Even if some dogs are not entered into dog shows to compete, different breeds of dogs have become more popular. Newer hybrids like the labradoodle, a mix between a labrador retriever and a poodle, or the puggle, breeding a pug and a beagle, are in high demand. Most people who like these hybrids enjoy the uniqueness and the look of these new breeds. The breeders choose the parents based on traits they feel will be favorable in the offspring.

Artificial selection in animals can also be used for research purposes. Many labs use rodents like mice or rats to perform tests that are not yet ready for human trials. Sometimes the research involves breeding these mice to get the trait or gene that is being studied in the offspring. Conversely, some labs are researching the lack of certain genes. In that case, mice without those genes would be bred together to produce offspring who are also lacking that gene so they may be studied.

Any domesticated or animals in captivity can undergo artificial selection. From cats to pandas to tropical fish, artificial selection in animals can mean the continuation of an endangered species, a new type of companion pet, or a lovely new animal to look at. While these traits may never come about through the accumulation of adaptations and natural selection, they are still achievable through breeding programs. As long as humans have preferences, there will be artificial selection in animals to make sure those preferences are met.