What makes a species?

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Did anyone work out exactly what defines a species?

 

Do you mean the definition of the word or people's interpretation of it?

If you're looking for a definition, why not try a dictionary or just search on the web. Darwin probably defined it although I've got bugger all idea what he said on that point.

If you're looking for a more interesting discussion regarding interpretation, then why not post the definition and we could debate it's merits?

Edit:

Species
the largest natural population of organisms that can interbreed to produce fertile offspring. Members of one species are reproductively isolated from members of all other species (i.e., they cannot mate with them to produce fertile offspring).

From: Classification of living things - by Dennis O'Neil, Ph.D.

I couldn't find it defined by Darwin, but I didn't look very hard.

[This message has been edited by Viking (edited February 21, 2002).]

 

Here is a list of several scientists' interpretations of the term "species" (albeit brief) including Charles Darwin and Carl Linnaeus (developer of taxonomic identification).

A separate search of individual concepts will prove to be more conclusive, but I think that this will help in deciding whom you feel is more accurate.
http://www.icr.org/pubs/imp/imp-211.htm

[This message has been edited by Xenecor (edited February 21, 2002).]

 

fantastic, good to know we've finally got this issue resolved after those comments by the squirrel and mule lovers.

 

I love squirrels!

 

slith- you've just gone up sharply in my in my estimations, thanks to your ingenious use of smilies.

 

I'm not sure about spices being just one animal. We're animals. I think that some day that were going to start interbreading with other spices to surive. Eather that or we're going to bread a new spices that goes all wrong and eats us all.

 

That's right dragonrider. Now take your medication and go to sleep there's a good lunatic.

 

Dragonrider, you have it ALL wrong. You see, it is us who eat the spices. Not the other way around.

Seriously though, in taxonomic identification... Animals are in the kindgom Animalia.... the largest portion of the identification system.
Kingdom
Phylum
Class
Order
Family
Genus
Species

Ergo, it is impossible for animals to be a single species.

 

ahhh that brings back so many mmemories of 7th grade biology, DAMN my cigarette smokin teach, DAMN HER!

 

whittaker's 5-kingdom classification has been obsolete for a few years now, Xenecor.

developed in 1977 (though only recently accepted) the 3-domain system developed by woese (based on variation between small subunit ribosomal RNA sequences) is now accepted by all evolutionary biologists ( the only scientists that matter!)

 

*sigh* Even by the most obsolete of systems.. it is impossible to say animals are species.. Anyway, that's not really the point so it doesn't matter.

 

you asked for it... there are SIX different species concepts:
1)morphological
2)evolutionary
3)isolation/recognition
4)cohesion
5)phylogenetic
6)biological

without going into too much detail... 1 is what non-scientists would believe distinguishes seperate species (differences in appearance), however 1 doesn't take into account sexual and developmental polymorphisms (latter- think e.g. tadpoles/frogs).

2 is monophyletic descent, for which there is obviously already a name for, and so can also be thrown out of the window.

3 can only be applied to sexual, biparental organisms and so is also not valid.

4=6 rewritten.

5 is quite interesting, arguing that the definition should be based upon the products of evolution rather than the processes that led to those products.

therefore 5 and 6 are the most likely. however, 6 -the biological species concept (reproductive isolation, discussed extensively in a previous post and above) is favoured because you are able to say what a species is at a (relatively) single point in time.

 

That was a really detailed and comprehensive reply. What are the three domains of classification by the way?

Thank god

 

Bacteria (Eubacteria), Archaea (Archaebacteria) and Eukarya (eukaryotes). the old terms (brackets) are the ones used at the beginning (1977) of the 'woesian revolution'.