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When is it a subspecies? (1 Viewer)

Like I said before, I think this is inconsistent and wrong. My solution, however, would not be to start carving the American House Sparrow in subspecies, but to remove clinal subspecies from other bird species such as the Song Sparrow. Such a classification would be more consistent, more rigorous, and less confusing (for both you and me!).

I've weighed in on this topic before, but I feel that naming the differences in organisms is a good thing - that way we can at least communicate about them. I agree with your point above that its a shame that government agencies, general public, etc. don't understand what a cline means with regard to taxonomy. But I don't think the answer is to rid ourselves of clinal subspecies. From a scientific standpoint, I don't see the problem with a pair of good, diagnosable subspecies with recognized intergrades between them. Ultimately, I think that the consistent, rigorous and less confusing classification is the one which best reflects reality.
 
I guess in this situation though, if your subspecies is clinal, where does one begin and the other end. Even subspecies proponents like Remsen do not favor recognizing clinal subspecies in a formal way.

I think informal names are fine however, I just don't think "official" latin designations are needed
 
I guess in this situation though, if your subspecies is clinal, where does one begin and the other end. Even subspecies proponents like Remsen do not favor recognizing clinal subspecies in a formal way.

I think informal names are fine however, I just don't think "official" latin designations are needed

I have to agree, the real difficulty comes when you start deliniating individual parts of a broken cline. Although trinomials can be very useful in designating particular genetic units that may be in the process of speciation, many are based on such small variations from the "type" that they should be considered to be within individual variation.

Chris
 
I've weighed in on this topic before, but I feel that naming the differences in organisms is a good thing - that way we can at least communicate about them.

We can communicate about geographic variation without giving names to different areas of species' range. In fact, I think the best way to communicate about this kind of geographic variation is with data. A good way to visualize this kind of data would be to map changes in some character across the geographic distribution of species--and you could have different maps for different characters. So going back to our House Sparrow example, you could generate a map that showed how plumage color darkens and and lightens across the American range of the House Sparrow. You could have a different map that shows how body size gets larger and smaller across the range. And down the line for all varying characters.

This method would eliminate the need to draw arbitrary lines through a character cline. It would also allow us to visualize how different characters may have differently shaped clines within species. Trying to shoehorn all of this geographic variation into a group of arbitrary taxa would be misleading because it would imply that character change across different characters (e.g. plumage, body size, etc.) is concordant, when it might not be.

Ultimately, I think that the consistent, rigorous and less confusing classification is the one which best reflects reality.

In my opinion, my method would do a much better job of reflecting the reality of geographic variation within species.
 
Hi All,
other commitments meant that I had to leave this thread alone for a while. Reading it now, I was tempted to leave it alone, because it has returned to the original topic and this post is risking to lead it astray again; I hope not.

If you follow this link it should take you to a pubmed search showing 98 papers for the search terms "Finnish founder effect". I believe what is happening is that a term that in one scientific area means something specific has been implemented to mean something different among a different group of people. Science is full of examples like that. For someone interested in medical genetics it is more important to answer the question of where/how did this disease come into this population than it is to think about how Indoeuropeans are found in both India and W Europe (if the models still say that there is that communality).

Regarding the other disagreement, I think it is mainly a question of semantics, because I think we agree that any small population will have significant genetic drift. We also agree that to the extent that a founder effect leads to a small population, the result will be genetic drift. So the effect of a founder even will be genetic drift in the generations after the founding, the hair splitting is whether the founding should be called a direct or indirect cause.

So sorry to start that much discussion over something which I in the first post called splitting of hairs!

Niels
 
Niels,

I suspected we had started talking past each other--meaning we had different ideas about the meaning of the terms we were using. You are absolutely right that different subdisciplines can use the same jargon, but with different meanings. For example, I worked for a while with some virologists studying bird flu, and they would refer to antigenic drift as simply "drift" or sometimes even "genetic drift." As you probably know, antigenic drift (which is actually driven by selection!) is a completely different phenomenon from the population genetics concept of "genetic drift." Needless to say, it was quite confusing.

Note, however, that it is the population genetics meaning of genetic drift that comes up in all these bird speciation/evolution papers. In fact, there is a huge literature in evolutionary biology about founder events and genetic drift that dates back at least 70 years to Ernst Mayr, when the evolutionary biologists of the "modern synthesis" began applying emerging genetic theory to speciation. I don't know of any evolutionary biologists who wouldn't say founding events increase drift, and that this increase in drift is a direct consequence of the founding event. I'm still not clear on the distinction of your medical definition of drift, but it doesn't surprise in the slightest that such a thing exists.

Bailey
 
I guess in this situation though, if your subspecies is clinal, where does one begin and the other end. Even subspecies proponents like Remsen do not favor recognizing clinal subspecies in a formal way.

What I should have explained better is that every subspecies traditionally has a diagnosis. The "end of the line" is where the subspecies does not fit this definition any more. This does, of course, mean that there is an integration zone in many species where individuals are not diagnosable to subspecies. So as a good example, the scientific name of a certain population of flicker might be Colaptes auratus auratus/cafer. I feel that this is a good use of nomenclature, far better than "Salmon-shafted Flicker!"

We can communicate about geographic variation without giving names to different areas of species' range. In fact, I think the best way to communicate about this kind of geographic variation is with data. A good way to visualize this kind of data would be to map changes in some character across the geographic distribution of species--and you could have different maps for different characters. So going back to our House Sparrow example, you could generate a map that showed how plumage color darkens and and lightens across the American range of the House Sparrow. You could have a different map that shows how body size gets larger and smaller across the range. And down the line for all varying characters.

Indeed, this would be very accurate for a detailed population study, and this sort of information should be included in any responsible paper regarding geo. variation. But it would be fairly impractical if I were getting a feel for multi-species assemblages or massive geographical area, for example. Ideally, there could be a lengthy description of character for each organism we study, but the clunkiness of this method is why Linneaus got rid of it.

There are times when subspecific designations are very useful, and times when they are not so much. For better or for worse, I don't think trinomials are going to go away any time soon. I think it best to refine their usage, however, if only for the purpose of effective and accurate scientific communication.
 
What I should have explained better is that every subspecies traditionally has a diagnosis. The "end of the line" is where the subspecies does not fit this definition any more. This does, of course, mean that there is an integration zone in many species where individuals are not diagnosable to subspecies. So as a good example, the scientific name of a certain population of flicker might be Colaptes auratus auratus/cafer. I feel that this is a good use of nomenclature, far better than "Salmon-shafted Flicker!"

Think about why you don't have an impulse to name that intermediate orange-shafted population as a different subspecies--that is exactly what you have been arguing up until now. Statistically, hybrid populations of Red-shafted/Yellow-shafted Flickers are just as diagnosable as all those clinal subspecies you're fighting for.

You are now making the same argument I would make: I say just call the intermediate population an intermediate population and don't bother giving it a scientific name.

There are times when subspecific designations are very useful, and times when they are not so much. For better or for worse, I don't think trinomials are going to go away any time soon. I think it best to refine their usage, however, if only for the purpose of effective and accurate scientific communication.

I'm not advocating we get rid of subspecies; I'm just arguing against clinal subspecies. My arguments are basically about how we should define the basal taxonomic rank. If you are a Biological Species person, this basal rank is the subspecies. If you are a Phylogenetic Species person, this basal rank is the species. However, whether you call the thing a species or a subspecies, I think we can come to broad agreement about how we define that basal rank.
 
There was a whole ornithological monograph devoted to subspecies. All authors were on the side of wanting subspecies, but they still differed in how to define them. See for example chapter 5.

Niels

The reason all the authors were on the side of wanting subspecies was because nobody with an opposing viewpoint was invited to submit a paper--but that is a different issue.

Tradition is tough to overcome, but I'm optimistic about the future of subspecies. I think we are slowly moving towards a more objective lineage-based approach. IMHO, we will be better for it.
 
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