Tuesday, May 12, 2020

Artificial Selection Breeding for Desirable Traits

Artificial selection is the process of breeding animals for their desirable traits by an outside source other than the organism itself or natural selection. Unlike  natural  selection, artificial selection is not 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 achieve the ideal pet in terms of looks and demeanor or a combination of both. Artificial Selection Renowned scientist  Charles Darwin  is credited with coining the term artificial selection in his book On the Origin of Species, which he wrote upon returning from the Galapagos Islands and experimenting with crossbreeding birds. The process of artificial selection had actually been used for centuries to create livestock and animals bred for war, agriculture, and beauty. Unlike animals, humans dont often experience artificial selection as a general population, though arranged marriages could also be argued as an example of such. However, parents who arrange marriages generally choose a mate for their offspring based on financial security rather than genetic traits. Origin of the Species Darwin made use of artificial selection to help gather evidence to explain his theory of  evolution  when he returned to England from his journey to the Galapagos Islands on the  HMS Beagle.  After studying the  finches  on the islands, Darwin turned to breeding birds— specifically pigeons—at home to try and prove his ideas. Darwin was able to show that he could choose which traits were desirable in pigeons and increase the chances for those to be passed on to their offspring by breeding two pigeons with the trait; since Darwin performed his work before  Gregor Mendel  published his findings and founded the field of genetics, this was a key piece to the evolutionary theory puzzle. Darwin hypothesized that artificial selection and  natural selection  functioned the same way, wherein traits that were desirable gave the individuals an advantage: Those who could survive would live long enough to pass the desirable traits on to their offspring. Modern and Ancient Examples Perhaps the best-known use of artificial selection is dog breeding—from wild wolves to  dog show  winners of the American Kennel Club, which recognizes over 700 different breeds of dogs. Most of the breeds the AKC recognizes are the result of an artificial selection method known as crossbreeding wherein a male dog from one breed mates with a female dog of another breed to create a hybrid. One such example of a newer breed is the labradoodle, a combination of a Labrador retriever and a poodle. Dogs, as a species, also offer an example of artificial selection in action. Ancient humans were mostly nomads who roamed from place to place, but they found that if they shared their food scraps with wild wolves, the wolves would protect them from other hungry animals. The wolves with the most domestication were bred and, over several generations, humans domesticated the wolves and kept breeding those that showed the most promise for hunting, protection, and affection. The domesticated wolves had undergone artificial selection and became a new species that humans called dogs.

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