Are Great Danes and Chihuahuas Different species?

[rmorse]

Hey all,

My girlfriend brought up an interesting point: Can Great Danes and Chihuahuas be considered different species? Since organisms are considered different species if they cannot produce viable offspring. The 2 dogs mentioned cannot produce viable offspring due to prezygotic barriers.

 

[kriztu]

i think not, both are c. familiaris, and so are other dogs. further classified to different breeds

 

[rmorse]

i think not, both are c. familiaris, and so are other dogs. further classified to different breeds

Yes, I know they are currently classified as the same species. However, my point was to say that there are prezygotic barriers in place to keep them from reproducing. Therefore, since they cannot produce viable, fit (in Darwin's sense) offspring, why aren't they separate species?

 

[WyldFya]

It is believed that the Chihuahua is actually a descendant of the Fennec fox of Africa. As such, there would be no genetic link between the Chihuahua and the Great dane. This, however, has not yet been proven, and as such can only be taken for a grain of salt.

Fennec fox (picture from http://snarla.files.wordpress.com/2007/03/fennec5.jpg)

 

[Tongue33]

Here is an interesting thread on this exact topic..

http://www.physicsforums.com/showthread.php?p=796717

 

[rmorse]

Here is an interesting thread on this exact topic..

http://www.physicsforums.com/showthread.php?p=796717

Interesting read, thank you!

It is believed that the Chihuahua is actually a descendant of the Fennec fox of Africa. As such, there would be no genetic link between the Chihuahua and the Great dane. This, however, has not yet been proven, and as such can only be taken for a grain of salt.

Fennec fox (picture from http://snarla.files.wordpress.com/2007/03/fennec5.jpg)

However, I can "breed up the line." I can breed a Chihuahua with a Jack Russel, get a medium sized offspring. Breed that with a Beagle. Get a larger offspring. (Etc until I reach a large enough offspring to reach a Great Dane) Which would suggest that a Chihuahua is the same species as all of the other dogs.


But on the other hand, I can't breed a Chihuahua with a Great Dane. Which suggests (according to the definition of a species that I learned in Biology) that they are different species.

 

[Tongue33]

Interesting read, thank you!





However, I can "breed up the line." I can breed a Chihuahua with a Jack Russel, get a medium sized offspring. Breed that with a Beagle. Get a larger offspring. (Etc until I reach a large enough offspring to reach a Great Dane) Which would suggest that a Chihuahua is the same species as all of the other dogs.


But on the other hand, I can't breed a Chihuahua with a Great Dane. Which suggests (according to the definition of a species that I learned in Biology) that they are different species.

I think you might be able to breed a female Grate dane toa male chihuahua... maybe????

 

[rmorse]

I think you might be able to breed a female Grate dane toa male chihuahua... maybe????

You can always artificially breed them. However, I do not see it happening naturally.

Female Great Dane:

Male Chihuahua:

 

[rmorse]

 

[Tongue33]