Semantic Web: What is a species?
An interesting side discussion started up from my earlier post and I thought it might beworth discussion on the general list. I expect there will be a number of different opinions on this subject which might prove enlightening.
What is a species?
The way I have constructed my system I consider species to be real things too which different taxonomic hypothesis are applied.
A collector or curator would then decide which species concept they believe is the best match for their specimen or group of specimens.
Those individuals would then be tied to a particular species concept. (Not necessarily a specific genus species)
Statements or properties could then be associated with particular species concepts.
For instance:
This Culicidoid species concept is a member of the Anophelinoid Group and thereby inherits the following properties:
Maxillary palps about as long as proboscus, not strongly recurved Scutellum evenly rounded Scutellum seta more or less evenly distributed Most like diagram http://.....
I am not sure that you could make useful statements like this if specimens are abstracted as an array of names, and if species are not real things that are separate from individual taxonomic hypothesis.
Note I use Anophelinoid rather than Anophelinae to avoid tying this group of morphological characters to a specific taxonomic hypothesis.
Under this model genera, families and subspecies (as they are now used) are thought of as human constructed clades and are not real in the same sense as species are real. A species exists whether or not a human has chosen to describe and name it.
There also seems to be a difference in how ecologists, medical entomologists and taxonomists think of species. The former tend to view species as real things while the later see them as a human constructed grouping, where the taxonomic hypothesis is the species concept.
From the perspective of the semantic web, species concepts defined in these
different ways have different meanings and may not be able to be merged directly. At least that is my current thinking ....
How do others think of species? --------------------------------------------------------------- Pete DeVries Department of Entomology University of Wisconsin - Madison 445 Russell Laboratories 1630 Linden Drive Madison, WI 53706 ------------------------------------------------------------
How do others think of species?
I do not think that species are any more "real" than subspecies, genera, and families. I believe all of these things are abstract notions representing aggregate sets of individual organisms, defined and labelled by humans in a way that allows us to communicate with each other with some degree of efficiency (though certainly not perfect efficiency).
Having said that, I think it is highly practical in many cases to treat units of "species" as though they were cohesive, singular, "real" entities that exist in nature (within a given slice of geologic time) independantly of human interpretations, because doing so also facilitates communication. This is particularly true in cases characterized by realtively broad periods/populations of phenetic and/or genetic stasis, homogeneity and consistency, punctuated by relatively small periods/populations of phenetic and/or genetic divergence, heterogeneity and spectral forms. I think the dangers and problems (nomenclatural instability, poorly supported hypotheses, confusing and conflicting lines of evidence) are most evident when people attempt to apply assumptions based on the "reality" of species to cases that are not so characterized.
Thus, I do not believe that species are "real", but I believe there are contexts in which is it useful to think of them as such.
I think the practice of identifying individual organisms to species concepts is mostly independent of whether those concepts represent human-defined constructs, or "natural" units that exist in nature independantly of human interpretations. Analagous to my view of species, I think that morphological and genetic characters are properties of organisms, but in many cases it is highly practical to treat them as though they are properties of "species", given the same caveats described above.
Aloha, Rich
Richard L. Pyle, PhD Database Coordinator for Natural Sciences and Associate Zoologist in Ichthyology Department of Natural Sciences, Bishop Museum 1525 Bernice St., Honolulu, HI 96817 Ph: (808)848-4115, Fax: (808)847-8252 email: deepreef@bishopmuseum.org http://hbs.bishopmuseum.org/staff/pylerichard.html
Richard you make several good points, and I should state that I see species as more "real" thanother ranks.
Perhaps this example might help show the distinction I am trying to make.
When a medical entomologist states that a species X, breeds in shallow ephemeral pools and has a preference for human blood meals do they mean
The taxonomic hypothesis A. o. has these properties or
the "natural" unit currently called A. o. has these properties ?
I think they mean the second and would benefit if the statements made about that natural unit could stay linked to the natural unit species concept over time.
Unfortunately under the "species is the taxonomic hypothesis" system they don't.
Does this help clarify the distinction I am trying to make?
Thanks!
- Pete
On Sat, Jan 24, 2009 at 6:55 PM, Richard Pyle deepreef@bishopmuseum.orgwrote:
How do others think of species?
I do not think that species are any more "real" than subspecies, genera, and families. I believe all of these things are abstract notions representing aggregate sets of individual organisms, defined and labelled by humans in a way that allows us to communicate with each other with some degree of efficiency (though certainly not perfect efficiency).
Having said that, I think it is highly practical in many cases to treat units of "species" as though they were cohesive, singular, "real" entities that exist in nature (within a given slice of geologic time) independantly of human interpretations, because doing so also facilitates communication. This is particularly true in cases characterized by realtively broad periods/populations of phenetic and/or genetic stasis, homogeneity and consistency, punctuated by relatively small periods/populations of phenetic and/or genetic divergence, heterogeneity and spectral forms. I think the dangers and problems (nomenclatural instability, poorly supported hypotheses, confusing and conflicting lines of evidence) are most evident when people attempt to apply assumptions based on the "reality" of species to cases that are not so characterized.
Thus, I do not believe that species are "real", but I believe there are contexts in which is it useful to think of them as such.
I think the practice of identifying individual organisms to species concepts is mostly independent of whether those concepts represent human-defined constructs, or "natural" units that exist in nature independantly of human interpretations. Analagous to my view of species, I think that morphological and genetic characters are properties of organisms, but in many cases it is highly practical to treat them as though they are properties of "species", given the same caveats described above.
Aloha, Rich
Richard L. Pyle, PhD Database Coordinator for Natural Sciences and Associate Zoologist in Ichthyology Department of Natural Sciences, Bishop Museum 1525 Bernice St., Honolulu, HI 96817 Ph: (808)848-4115, Fax: (808)847-8252 email: deepreef@bishopmuseum.org http://hbs.bishopmuseum.org/staff/pylerichard.html
tdwg mailing list tdwg@lists.tdwg.org http://lists.tdwg.org/mailman/listinfo/tdwg
First, I think the comment that I *most* agree with is the one made by Gurcharan Singh, that these conversations are endless (and will probably always be so). There are two reasons I can never seem to miss an opportunity to dive in and pontificate (Jim C., that's your cue...):
1) I usually have a slightly different perspective at the end these conversations, than I had at the beginning (always a good thing); and
2) I enjoy the intellectual challenge of trying to make the same basic points each time using a different tact, and coming from a different perspective.
Now, Pete:
When a medical entomologist states that a species X, breeds in shallow
ephemeral pools and
has a preference for human blood meals do they mean
The taxonomic hypothesis A. o. has these properties or
the "natural" unit currently called A. o. has these properties ?
Frankly, I don't think most medical entomologists think that deeply about it. In fact, I don't think most taxonomists even think that deeply about. I suspect most biologists/scientists/laymen think of species as "things" that exist in nature, and that these "things" have certain properties that are consistent enough to allow predictions and such. And I would wager that, in the vast majority of cases, they would do so with good success. That doesn't make species "real" in my mind (or even any more "real" than other taxonomic units -- in fact I think populations are probably more demonstrably "real" than species). It just makes the notion of "species as real" a practical one (as if we didn't already know that, after centuries of people thinking in those terms).
I think they mean the second and would benefit if the statements made
about that natural unit
could stay linked to the natural unit species concept over time.
Unfortunately under the "species is the taxonomic hypothesis" system they
don't.
Does this help clarify the distinction I am trying to make?
I'm not sure -- partly because I've never quite understood what people mean by "species are hypotheses". By my reckoning, it's only an hypothesis if it's testable & falsifiable. As such, it only makes sense in the context of "species are real entities in nature, and we can test whether our circumscriptions (aka taxon concepts) match those real entities". So I've always thought of "species are hypotheses" and "species are real, natural entities" as being two sides of the same coin.
So I guess I don't understand the distinction you're drawing between the two.
Aloha, Rich
participants (2)
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Peter DeVries -
Richard Pyle