"Artificial Selection"

Bottle_of_Smoke

When people talk about evolution and selection of domestic animals it is usually referred to as "artificial selection"

Now I can see why this is done, as it refers to genetic traits selected by humans.

In a sense though, isn't this still "natural selection"? the gene which has an advantageous phenotype is selected. Is a human selecting a fast greyhound for studding really all that different from a female wolf selecting a particularly strong male wolf to mate with?

The reason I ask is when talking about examples of evolution and you refer to a domesticated animal people respond with "oh but that's artificial selection" even if it isn't relevant to the point.

Is it possible too much emphasis is put on the difference between artificial selection and natural selection?

Bottle_of_Smoke

Sorry thought I was still in atheist/agnostic forum, too late to delete. Can a mod move please?
Thanks

Scofflaw

So moved.

moderately,
Scofflaw

Rev Hellfire

Bottle_of_Smoke wrote: »

In a sense though, isn't this still "natural selection"? the gene which has an advantageous phenotype is selected. Is a human selecting a fast greyhound for studding really all that different from a female wolf selecting a particularly strong male wolf to mate with?

But that's not how we typically breed animals, take for example the turkey which is now breed to have a bigger breast but to the expense of the animals legs which now have problems bearing the animals weight. Or in the case of the dogs such as the bulldog which are breed for looks and as a result are susceptible to health issues.

In nature these characteristics would be breed out since they make the animals susceptible to either disease or predators. So I think a distinction is merited.

Caoimhín

Is there not a biology forum?

Good question though. In my own profession there is a theory that Beech is a native tree to the UK and Ireland because it was introduced by man. It has now naturalised and therefore could be considered native.

MagicMarker

I suppose all you have to do is look at the meaning of the words involved...

natural |ˈna ch ərəl|
adjective
1. existing in or caused by nature; not made or caused by humankind

artificial |ˌärtəˈfi sh əl|
adjective
1. made or produced by human beings rather than occuring naturally, typically as a copy of something natural

robindch

Bottle_of_Smoke wrote: »

When people talk about evolution and selection of domestic animals it is usually referred to as "artificial selection"

Natural selection refers to the unconscious selection of traits, while artificial selection is the conscious selection -- ie, farmers interbreeding their best sheep, horsey people their best horses to produce "better" and "better" animals.

It's a vaguely invidious distinction since it assumes that what people do naturally isn't "natural" in the "in accordance with nature" meaning of the word -- it's creating a difference that doesn't really exist.

Ickle Magoo

Bottle_of_Smoke wrote: »

When people talk about evolution and selection of domestic animals it is usually referred to as "artificial selection"

Now I can see why this is done, as it refers to genetic traits selected by humans.

In a sense though, isn't this still "natural selection"? the gene which has an advantageous phenotype is selected. Is a human selecting a fast greyhound for studding really all that different from a female wolf selecting a particularly strong male wolf to mate with?

The reason I ask is when talking about examples of evolution and you refer to a domesticated animal people respond with "oh but that's artificial selection" even if it isn't relevant to the point.

Is it possible too much emphasis is put on the difference between artificial selection and natural selection?

The difference being natural selection chooses traits beneficial to the animal while man chooses traits beneficial to man. Although the process of breeding is natural and so is gene selection, I don't think deliberately picking characteristics that are often harmful and negatively impact on an animals health and using artificial insemination in some cases to ensure man gets exactly what he wants could be considered a natural selection as the animal would have if left to it's own devices...

bnt

the gene which has an advantageous phenotype is selected.

Advantageous to whom? Rarely to the animal. There are dog and cat breeds that have been so heavily inbred, in pursuit of certain "desirable" features, that they suffer from all manner of congenital conditions and would not survive if they weren't kept as pets. It's not as if selective breeding is completely artificial, since there's an inevitable overlap between man's requirements and nature's. You want the lungs on the inside, for example. :eek:

But the crucial detail is in the definition of "advantageous". Which traits are advantageous? Who decides, and why? Can we foresee all the consequences? (Short answer: no, we can't.) I don't think I need to go in to the history of Eugenics, its uses and misuses, for you to get why we're a little sensitive on this topic. Let's just say that it makes sense to draw a clear line between natural selection - which happens whether we like it or not - and human-directed (unnatural) selection, which we do (or not) by choice. If you conflate the two, you get crap like the film Expelled. :mad:

Nemi

Bottle_of_Smoke wrote: »

Is it possible too much emphasis is put on the difference between artificial selection and natural selection?

You have a point. In "The Origin of Species" Darwin actually relies quite a lot on the fact that 'artificial selection' was used by animal breeders, as its proved that something allowed traits to be inherited. He then sort of takes a step back and says, "OK, we know what traits an animal breeder will choose. What traits would nature choose?"

Darwin needed to do this as, remember, genes and DNA and so forth had not been discovered. So you could guess that the fact of children looking like parents meant that something was passed on, the actual mechanism for doing so was unknown to Darwin.

So, yup, you are standing in Darwin's shoes there.

Improbable

Within terms of actual differences between them aside from the obvious (non-intelligent vs. intelligent driving forces), broadly speaking, natural selection chooses for traits which are advantageous to successful propagation of a species. Artificial selection (which I did quite a bit in directed evolution experiments) can be choosing for any trait that you desire, and not necessarily advantageous ones.

Zombrex

like Robin said it is more of human distinction than anything else. Despite the fact that we are a naturally occurring biological life form we tend not to think of what we do as natural. So if a lion eats his cubs that is "natural" but if we build an atomic bomb it is unnaturally.

From a purely Darwinian point of view a feedback system is a feedback system, whether it is a volcano blocking out sun light or a human fishman selecting crabs that look like people's faces. The process of Darwinian evolution is the same.

sponsoredwalk

https://www.youtube.com/watch?v=N5ztOEFoyw4

Nature choosing which organisms will reproduce is natural selection.
People choosing which organisms will reproduce is artificial selection.

Natural selection is defined as interacting with phenotypic characteristics,
genotypic expression obviously controls what phenotypic traits will occur
but nature, or humans, will most likely select what will survive and reproduce.
Obviously there's a lot more involved like sexual selection and bad genes
etc... but that's the jist of it, unless I'm mistaken.

Des Carter

Is the term not "selective breeding" or is that something else?

CerebralCortex

One could argue that artificial is a subset of natural.

Pushtrak

AronRa has a video which I feel best posted here.

Scarinae

I think another important distinction is that artificial selection has an endpoint in mind - for example, you might mix a beautifully-coloured but scentless rose with a scented but not-so-beautifully-coloured rose to get a specific outcome, in this case a beautifully-coloured and beautifully-scented flower.

However, natural selection is not directed with an endpoint in mind - it is a long sequence of random mutations that happen to be advantageous to the selection pressures of whatever environment the organisms are living in, over a long period of time. There is no design, or plan, just chance

Nemi

Fishie wrote: »

However, natural selection is not directed with an endpoint in mind - it is a long sequence of random mutations that happen to be advantageous to the selection pressures of whatever environment the organisms are living in, over a long period of time. There is no design, or plan, just chance

In one sense, I know what you mean. However, bear in mind that "advantageous to the selection pressures of whatever environment the organisms are living in" is not chance.

And breeding bloodstock, or any other process where humans are directing the selection, is really just an environment in which (like any other) certain traits confer a reproductive advantage. Maybe having a long beak confers an advantage in some environments. Whether that environment is one where a human is developing this trait for some experimental reason, or one where a long beak helps the bird to get worms, its essentially the same thing.