Defintion Of 'species'

[Bullrock74]

I thought the reason animals were classified into different 'species' was because animals of different 'species' were not able to reproduce. Isn't that the definition of 'species' or am I mistaken?

 

[jayjay]

You are mistaken. Species can hybridize.

 

[Bullrock74]

You are mistaken. Species can hybridize.

I know they can, what I meant was since they can, shouldn't they be classified together? According to dictionary.com members of different species cannot breed.

http/dictionary.reference.com/search?q=species&x=49&y=15

 

[jayjay]

No, as they are different. Like convicts and sajica are different but can breed together.

 

[Bullrock74]

So, you are saying that they are classified differently because they have different features? That is what doesn't make sense to me. Can they breed or not, to me, that should separate classes.

 

[CFC]

Species of the same Genus can hybridise in the wild, cross Genus hybridisation is more difficult and requires human intervention. Families cannot Hybridise (yet).

 

[Ben L]

Physicall features are deffinately important as well as if they can reproduce, afterall the fish classification system we use as guides to species relies mostly on fin-ray counts and scale counts as well as skeletal structure, however the ability to reproduce is important.
Remember also many hybrids are sterile so there is more to take in to account than if the individual parents reproduce, you need a second generation.

 

[Doggfather]

According to my biology books, there is no universally recognised definition of 'species'...just as there was no "official" definition of 'planet' as of a couple of weeks ago...

The most commonly used definition was suggested by Ernst Mayr (famous evolution biologist) who stated that species are "groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups". Now, given the wide range of genetic manipulation techniques, etc, this definition is filled with flaws...

So, you are saying that they are classified differently because they have different features? That is what doesn't make sense to me. Can they breed or not, to me, that should separate classes.

On a genetic level, yes, each species would be slightly different. When two members of the same species breed, they are able to produce fertile young (their offspring are able to produce offspring of their own...). That said, two differnt members of the same genus are also able to reproduce,however, their offspring is infertile. Which is why you can't breed two mules, as mentioned above.

So, to sum it all up, theres no definative definition of the word 'species' and members of the same genus can hybridize natrually to produce infertile young.

Hope that kinda helps...it's late, so if any part of the above post is incorrect, sorry, but it seems to be making sense to me now

 

[jayjay]

I think it's normally the male who is infertile but some are now fertile hybrids I think. Also you can breed a hybrid with a normal (pure) fish aswel I think.

 

[00mitomk]

isit forced ?? like making hybirds ??? like gettin ligers tht was forced ( corss between tiger and lion )

miles

 

[mikev]

To the original poster:
Tigers+Lions
is one very good example...

So, to sum it all up, theres no definative definition of the word 'species' and members of the same genus can hybridize natrually to produce infertile young.

Hmm... usually infertile, but not always.

 

[OohFeeshy]

With fish species definitions are mostly defined on appearance and counting of scales, rays etc, but obviously there's regional variations which can screw up appearences. I don't think the breeding aspect is as important as in mammals, because most fish use external fertilization hybridisation isn't quite as difficult with similar species.

 

[Herpetology!]

A species is a group of independently reproducing animals, a population that has the potential to reproduce with closely related species but is usually physically barred by obstacles such as mountains (or in the fish case dry land). Species can be a very subjective definition.

By the way, I'm in biology in university

 

[britanix]

Depending on their genetic simalrities, members of one species can reproduce with members of another. However, 99% of the time the offspring is infertile. Kind of like natures way to stop things getting out of hand. For examples just look at the mule and the liger.

 

[bluefire]

yeh, even on the odd chance that hybrids are able to reproduce the offspring will eventually die early in development or won't be able to produce a fertile F2 generation.

thats what we were taught in biology anyway