Can you compare selective breeding to natural selection?

Please use as much detail as possible.

1 Answer
Mar 17, 2018




Selective breeding goes into a category called artificial selection, or basically human-caused natural selection.

In natural selection, favorable traits are selected for by way of all organisms with unfavorable traits will either die or be unable to reproduce.

Example: a bird population migrates to a new area where their only food source is a fruit growing on a cactus. If some of the birds have longer beaks, they will be able to get the food, while the shorter-beaked birds will not. The ones with short beaks will starve, while the ones with long beaks will thrive and reproduce with one another. Thus, even in a generation, natural selection has changed a population entirely.

In artificial selection or selective breeding, the idea is the same, but the mechanism is us not nature. A prime example is a type of crab in Japan. The Japanese culture has idolized the samurai for thousands of years, and their culture has revolved around fishing a lot because they're an island.

When the Japanese hunted crabs, they would often find a crab with a shell that resembled the face of a samurai. Out of superstition, they let these crabs live, and ate the crabs without these strange markings. Over time, more and more of the crabs ended up having these samurai markings because we selected for it, and the crabs that had the trait would survive, while the ones without it would be eaten.

In dog breeding, you could make the same connection. We choose dogs to mate, and once they do, we choose the pups with the best traits and breed those, and prevent the ones without those traits from breeding. Over time you end up with hundreds of dog breeds that look vastly different, but are genetically almost identical to wolves from which they were selectively bred.