Artificial selection has resulted in plants that are more disease-resistant, cows that produce more milk, and racehorses that run faster. One must wonder what will come next. In the blog entry answer the following question - under what circumstances should humans be artificially selecting plants or animals, if any?
What is Artificial Selection, and how is it being used?
Artificial selection, or selective breeding, is genetic selection which is controlled by people, within a genetically diverse population. Artificial selection is the basis of both domestication, and modern plant and animal breeding. It’s being used to breed plants and animals that contain
Artificial selection, or selective breeding, is genetic selection which is controlled by people, within a genetically diverse population. Artificial selection is the basis of both domestication, and modern plant and animal breeding. It’s being used to breed plants and animals that contain
all of the genetic traits that we desire, and none of the ones that we don’t. Upon first contact with the subject you might assume that artificial selection is the opposite of natural selection, however it’s not really a simple case of black and white. It’s “artificial” selection, not because it makes use of genetic engineering and tampering, but because there is an influence on the types of species that breed. Artificial selection is most prominently present in the case of domesticated animals, such as dogs. In this case, breeders would simply promote breeding between
dogs having desirable characteristics, and discourage breeding between dogs that do not. Evolutionary biologists view domesticated breeding as a type of natural selection, but with adaptive change in organisms under human control.
The proposal of this idea
The notion of artificial selection was expressed by the Persian polymath Abu Rayhan Biruni in the 11th century. He suggested the idea in his book entitled India, and gave various examples of it, some of which are described in the following statement by Biruni:
“The agriculturist selects his corn, letting grow as much as he requires, and tearing out the remainder. The forester leaves those branches which he perceives to be excellent, whilst he cuts away all others. The bees kill those of their kind who only eat, but do not work in their beehive.”
Another prominent figure that spoke of artificial selection was Charles Darwin, who used the term twice in his book, On the Origin of Species. In the first reference, he wrote about the complex and beautiful things he believes that humans can create through artificial selection. In the second reference, he used the term to describe the reasons for differences in animal breeds in countries with different development levels. Darwin, however, did not clearly define the term in his book.
“The agriculturist selects his corn, letting grow as much as he requires, and tearing out the remainder. The forester leaves those branches which he perceives to be excellent, whilst he cuts away all others. The bees kill those of their kind who only eat, but do not work in their beehive.”
Another prominent figure that spoke of artificial selection was Charles Darwin, who used the term twice in his book, On the Origin of Species. In the first reference, he wrote about the complex and beautiful things he believes that humans can create through artificial selection. In the second reference, he used the term to describe the reasons for differences in animal breeds in countries with different development levels. Darwin, however, did not clearly define the term in his book.
The Cons
Inbred offspring are one of the potential dangers of too much artificial selection. Some traits are so rare that they may only exist in one or two family lines. If the trait is recessive, two relatives may have to be bred together in order for the trait to be expressed, or visible. In animals, this can result in genetic defects and other serious problems.
In many cases, artificial selection has been used for aesthetic improvements, while hurting the subject’s ability to function or survive. The domestication cycle of dogs being bred by their owners in order to emphasize less-aggressive traits has gone on for thousands of years, and has resulted in hundreds of different breeds that look almost nothing like their ancestor (grey wolf). Dairy cattle are also bred using artificial selection in hopes of producing more milk, but some lines now suffer from increased infections and fertility problems. Persian cats that are bred for extremely flat faces often develop respiratory problems and may have trouble eating. All of the listed traits that are bred for do not help the animals survive in the wild, but do make them more desirable to their owners.
When you hear that artificial selection can help us to create cows that produce better milk, racehorses that run faster, or dogs that are less aggressive and more obedient, your first thought will most likely be that it’s a great method of breeding, and you’ll support it entirely (unless, for some reason, you’re against progress). However, like all great things, we must still be conscientious and aware of the problems that it could cause. Not many people are aware of the seriousness of artificial selection and I believe that until it is known to more people, the only thing it can do is cause problems in the future and get way out of hand. I personally think that "oh natural" is the way to go. I Don't think it is necessary to change the growth or breeding patterns of food or animals in any way. I think science is way ahead of our time and things are getting a little bit too carried away these days.
Sources - daniella's bio blog
http://www.opbf.org/open-plant-breeding/glossary/a
http://en.wikipedia.org/wiki/Artificial_selection
http://www.wisegeek.com/what-is-artificial-selection.htm
In many cases, artificial selection has been used for aesthetic improvements, while hurting the subject’s ability to function or survive. The domestication cycle of dogs being bred by their owners in order to emphasize less-aggressive traits has gone on for thousands of years, and has resulted in hundreds of different breeds that look almost nothing like their ancestor (grey wolf). Dairy cattle are also bred using artificial selection in hopes of producing more milk, but some lines now suffer from increased infections and fertility problems. Persian cats that are bred for extremely flat faces often develop respiratory problems and may have trouble eating. All of the listed traits that are bred for do not help the animals survive in the wild, but do make them more desirable to their owners.
When you hear that artificial selection can help us to create cows that produce better milk, racehorses that run faster, or dogs that are less aggressive and more obedient, your first thought will most likely be that it’s a great method of breeding, and you’ll support it entirely (unless, for some reason, you’re against progress). However, like all great things, we must still be conscientious and aware of the problems that it could cause. Not many people are aware of the seriousness of artificial selection and I believe that until it is known to more people, the only thing it can do is cause problems in the future and get way out of hand. I personally think that "oh natural" is the way to go. I Don't think it is necessary to change the growth or breeding patterns of food or animals in any way. I think science is way ahead of our time and things are getting a little bit too carried away these days.
Sources - daniella's bio blog
http://www.opbf.org/open-plant-breeding/glossary/a
http://en.wikipedia.org/wiki/Artificial_selection
http://www.wisegeek.com/what-is-artificial-selection.htm
