Evolution?

Question

Is artificial selection in any way related to the theory of evolution? I know that natural selection is the guiding force of evolution (I could be wrong), but when people selectively breed dogs to exaggerate desired traits is that man made evolution? I know I should probably know this, and I’ve read up on it, but I still don’t understand this concept. Can anybody help?

I never said selective breeding was artificial selection. What I said was "Is artificial selection in any way related to the theory of evolution?" I was merely comparing both artificial selection and natural selection. Sorry If I mislead you.

Again, what I'm asking is if artificial selection is "man made evolution?" I'm sorry if I was unclear.

Sorry, in the second entry I meant "I never said selective breeding was natural selection." My mistake.

Oggie, sorry but that makes no sense at all.

Answer 1

Yes. You've already been given examples of dog selection below (where the source material was wolves.)

At the moment, because all dogs can interbreed with another - thru a series of sizes, we wouldn't consider them a species. It could be considered more like cline similar to that in the California salamander (Ensatina eschscholtzi). http://www.pbs.org/wgbh/evolution/library/05/2/l_052_05.html

Now assume for a moment that for some reason, people's change in taste, heat tolerance, whatever, that all the dogs except for the Saint Bernard and the Chihuahua vanished tonight. There is an absolute physical impossibility that the male St Bernard and the female Chihuahua could cross. Basically, we have created two new species. Further selection over time would tend to increase differences between the two and sooner or later there would likely be mutations that would also inhibit fertility even if crossing were possible.

To all intents and purposes then, artificial selection would have created two new species -- in the same way that natural selection and separation create actual species. (By definition, we simply don't call what humans create a "species", but we could if we vary the definition.)

Answer 2

Selective breeding is exactly like evolution, but we select what we want instead of letting it happen according to the environment. In nature, there is no guiding force, only survival counts. This means that the environment has the last say in how animals evolve.

In selective breeding, we decide which animals should survive and what traits we want. That is how almost all of our food crops and vegetables came to be. You will not find wild squash, tomatoes, and string beans because they don't exist in nature. Humans selected and bred them.

So you can say that artificial selection or breeding is a form of directed evolution.

Answer 3

Yes. You are absolutely correct!

Artificial selection is identical to natural selection, except that the breeder is supplying the selective filter. I.e. the breeder (rather than nature) defines what traits are "advantageous" and selects those individuals that have those traits for breeding future generations, while those individuals that lack those traits are culled (kept out of the breeding pool).

I bred shetland sheepdogs (shelties) for a while, and was close to a family who bred dairy goats, but it's the same if you breed orchids, or champion tomatoes ... they all use the exact same principles of genetics that natural selection operates on. E.g., a "scooped" shape to the bridge of the nose, and ears that fold over are considered desirable traits for a sheltie, and therefore "advantageous" in the "survival of the fittest" environment of a dog show. Puppies with flatter noses or pointy ears are neutered and sold or kept as pets. Dogs that grow up to have all the traits needed to win dog shows become preferred breeders. In this way, after a few generations a breeder sees a noticeable difference in the appearance of their dogs.

The modern dairy cow, for example, is the product of human-directed evolution, that would never survive long in the wild. The ultra-flat topline, the size and structure of the udder, the size and consistency of the bones etc. are all products of selective breeding for one purpose, milk production (which includes longevity).

Dog breeds from great danes to chihuahuas are all descendants of the same basic animal, Canis domesticus. All great examples of how much variation nature can carry in DNA, and still produce viable offspring. Of course, this is happening on a short time-scale of at *most* 10,000 years (since the domestication of dogs ... but probably much more recent w.r.t. selective breeding), and it would take hundreds of thousands of years to produce different *species* ... but that does show the basic principles that drive evolution, in action.

Answer 4

Of course evolution is true; it is an established fact as evidenced by repeated biological, chemical, paleontological, geological, and even astrophysical measurements…PERIOD! The only debate is HOW evolution occurs (i.e., by which processes). All that aside, your third update pretty much gets to the heart of your original question. Evolution is the process whereby things (including living things) change over time. Many factors can influence the evolution of something. If the process is natural (including catastrophes such as a meteorite impact) or if it is consciously induced by subjecting the organism to a regime of selective breeding, the change over time is still by definition part of the process called evolution.

In his posting, Bombshell007 brings up an interesting point about Lamarckian inheritance (after Jean-Baptiste Lamarck who lived around the American Revolutionary War). Lamarck theorized that organisms evolved by passing on acquired traits to their offspring. His example of the giraffe presumed that each successive generation stretched their necks a little further and so over time their descendents had longer necks (he was right about change over time, but he didn’t know about genetic inheritance and thus did not understand the mechanism). Many experiments were done by cutting the tails off generations of mice, but new ones were always born with tails the same as their parents. Thus, Lamarck’s ideas were rejected because his theory about the mechanism was not supported by evidence. By the end of the 19th century, Gregor Mendel conducted experiments with the breeding of peas and learned that traits were inherited from parents with only the rare and occasional modification. It was not until the middle of the 20th century that the DNA in our genes was shown to carry this inherited information.

Answer 5

Man can make other men they may be bigger and stronger according to parents genes. The same with dogs you can breed any kind of dog with another type of dog and get a dog, but you cant get a cat from a dog. My point is I do not think that evolution is true. Can you breed a ape with a human and successfully have a child. I don't think so! I did not come from an ape there a different species. Just like you cant get a cat from a pit bull. God made a lot of different species of animals and that's the only species there are. This is just my opinion and everyone has a right to there opinion.

Answer 6

Yeah, you've pretty much answered your own question. Man-made selection is one thing that can affect evolution. Pets and livestock are just one example. We've also really changed crops, flowers, and pretty much any other living organism that we use for commerce.

Basically, by only propagating offspring of a particular type (e.g. corn with big kernels or big, juicy oranges), we gradually affect the genetic makeup of those crops. Over time, we find the 'best' sample and over many generations, completely different-looking offspring arise. This is how we turned a big bad wolf into a lap dog that sells tacos. It sure smells like evolution to me.

Answer 7

when humans breed dogs to acquire specific traits, that isn't natural selection. natural selection is when an animal is either able to survive by changing to adapt to specific climates, or dies off because of the inability to do so. artificial selection is not evolution because it isn't a naturally ocurring phenomenon, it's done by humans for purposes other than survival.

Answer 8

Selective breeding is what it's called. And you could certainly compare it to evolution, but it is indeed different, because the thing that determines who gets to reproduce in selective breeding is a human who is looking for certain characteristics, whereas in natural selection, it is the environment itself that "selects" for certain characteristics; animals better suited to that environment survive more easily, and therefore reproduce more easily.

Answer 9

hi! what do you mean by artificial selection? i know natural selection though. through natural selection, organisms evolve and adapt to the environment with the adaptations that best suit them. i don't think man-made evolution is possible (maybe). example: if a mother dog has cropped ears, the offspring will not because cropped ears is not encoded in the genes.

Answer 10

I believe artificial selection is already affecting evolution. By curing diseases that would otherwise result in death, we are interfering with the natural selection that could lead to resistance to that disease.