Has any experiment been done to create new un-interbreedable species by artificial selection?

 

I am assuming this experiment would have to go on long enough for the new species to be placed in a different category from the original species. The higher up the category the better (ie: order>family>genus).

Dogs. Just try to breed a great dane with a chihuahua. They're an excellent example of both how drastically selection can alter appearance and how two animals with a *very* close common ancestor can become genetically separate.

Dogs. Just try to breed a great dane with a chihuahua. They're an excellent example of both how drastically selection can alter appearance and how two animals with a *very* close common ancestor can become genetically separate.

 

never actually thought about that. but they are still both dogs.

 

i was thinking more along the lines of them actually being classified as seperate species or even higher as a seperate genus or order.

 

or would that take to long to make happen?

dogs again.

 

dogs started off as domesticated wolves, over time the were selectively bred into the gamut of dogs you see today which are a different species from wolves. this took a few thousand years.

 

things with shorter generation times(fruitflies or bacteria) can be bred into a different species in a matter of months or years.

It's worth noting that the term "dogs" is meaningless, especially since it can include members of different genera (such as the African Wild Dog). We only apply it because we know their ancestry. Someone who had never seen of heard of these breeds might well split them into separate species, based on massive morphological differences and inability of some combinations to mate effectively.

 

"Genus" and "Family" are also artificial concepts that humans have imposed for our convenience. There's no rigid definition for them, especially not in terms of the amount of change required, and the term does not necessarily have uniform meaning (there can be more diversity in a single beetle genus than in an entire mammal family, for example).

Also, species concepts tend to break down if you look at, e.g. prokaryotes (not that it prevents us from assigning names, that is).

There is acutely a much more dramatic example then dogs: corn. Modern corn(maize) was obtained though thousands of years of the selective breading of the field grass teosinte starting with the Aztecs. Teosinte and corn share virtually no characteristics except that teosinte’s seeds (technically a vegetable and not a seed) are divided into tiny kernels like corn. The Aztecs somehow had the vision to selectively bread thousands of tiny changes into teosinte to get modern maize.

 

http://en.wikipedia.org/wiki/Maize#Origin

Edited July 25, 200916 yr by bob000555
added a referance

Creating new species of fruitflies in few years!! Has this been actually tested?

yep. its been done sevaral times in labs.

 

its only possible within the human life span because fruitflies breed so quickly.

I would suggest one revision to the original question "Has any experiment been done to create new un-interbreedable species by artificial selection?" 

"Species" is not based on whether two organisms CAN interbreed but whether they DO interbreed in the wild.  A lion and a tiger can be successfully bread even though they are of different species, but in the wild they don't.  

I think that example is illustrative of two important things: 1) The dividing line between species is fairly fine-grained.  If you ask someone to name all the animals they can think of the list might include "squirrels, chipmunks, lions, tigers" but those names tend to be at the genus or even family level.  There are a bunch of species of squirrel.  2) Despite that, the definition of a species is still relevant because it is based on the flow or lack of flow of genetic information.  A barrier to gene flow determines whether a mutation has the potential to spread throughout the species or bifurcate the species.   Gene flow is also a lost less subjective than morphological similarity of difference.  Even with the ambiguity around what counts as a species or not (prokaryotic don't conform to that definition very well), I've heard "species" described as the only taxonomic level that is not entirely arbitrary.

The biological species concept, the most common version, relies on the ability to interbreed.  However, barriers to hybridisation come in various forms.  If you breed a subspecies that has a different appearance, these new individuals might be less attractive.  This would be a pre-zygotic barrier.  Post-zygotic barriers prevent the normal development of the hybrid zygote.  For example, the mule embryo does not abort, but the mule doesn't develop sexually.

Although the point might be moot, I believe sexual selection is ultimately the selection of zygotes.  A male can be fit and attractive, but he also releases many sperm with varying degrees of health.  The selection of healthier sperm might be more important for organism that release spores, or the aquatic sperm involved in alternation of generations.  Perhaps the right environment would cause their sperm to evolve more rapidly than either the gametophyte or the sporophyte.

This thread is from a decade ago!

Mules are infertile crossbreeds between horses and donkeys.