# Biological taxonomy and 'race' **URL:** \ **Category:** Factual Questions\ **Created:** [March 12, 2006, 3:50pm UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047 "2006-03-12T15:50:45Z")\ **Posts on this page:** 10\ **Page:** 3
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 14, 2006, 12:23am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/41 "2006-03-14T00:23:14Z")
> [@Tourt Eroglik](#): > > Where did you get this 1000km figure? It was completely arbitrary. I was just giving an example of a typical case. > [@](#): > > And no, I’m not sure you fully understand the PSC. The PSC does not declare A and B to be separate species just because they are diagnosable. This sounds more like Linnean phenetics. I’m not sure anyone fully understands the PSC, including Cracraft himself. 😉 Nor the BSC, for that matter, including the late lamented Ernst. I was simplifying for the sake of this thread. I don’t really want to get involved in a discussion of the pros and cons of the PSC and BSC here. > [@](#): > > No, the PSC is merely a tool for identifying what _could_ be species, based on ancestry and shared characters, via cladistic analysis. It then requires an actual research program (beyond the cladistics that many consider the PSC to be) to determine if specation has been both initiated and completed. Which makes the PSC just about as weak in practice as the BSC is alleged to be. > [@](#): > > I high recommend, especially if you are attempting to describe a species, _The Nature of Diversity: An Evolutionary Voyage of Discovery_ (Brooks & McClennan 2002). It goes into great detail regarding the phylogenetic methods. I know how to describe a species, thank you very much. It’s just that this particular case is possibly going to embroil me, for reasons I don’t want to go into here, with one of the grand gurus of the PSC. It’s sort of like marrying outside one’s religion. 🙂 ---
**Author:** ![Tourt\_Eroglik](https://avatars.discourse-cdn.com/v4/letter/t/977dab/32.png) [@Tourt\_Eroglik](https://boards.straightdope.com/u/Tourt_Eroglik)\ **Post date:** [March 14, 2006, 12:30am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/42 "2006-03-14T00:30:19Z")
> [@Colibri](#): > > No, it doesn’t ignore history at all. It merely considers present gene flow to be more significant in defining species. I’m not so sure you should be attempting to describe a species of bird if you don’t see how the BSC ignores history. It is a non-dimensional species concept. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 14, 2006, 12:30am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/43 "2006-03-14T00:30:26Z")
> [@Tourt Eroglik](#): > > Are botanists no longer considered biologists, then? Oh, they’re biologists all right, but they’re kind of weird. Not as weird as herpetologists, though. The stories I could tell about the herp guys on our Gabon expedition would make you blanch! :eek: > [@](#): > > You guys have probably had this already, but perhaps a thread regarding species concepts is in order. Actually I was thinking of writing up a Staff Report on it, after I get done with “the wild ancestors of hamsters” and “the evolution of the human butt,” which are also on my Mailbag “to do” list. 😃 ---
**Author:** ![Tourt\_Eroglik](https://avatars.discourse-cdn.com/v4/letter/t/977dab/32.png) [@Tourt\_Eroglik](https://boards.straightdope.com/u/Tourt_Eroglik)\ **Post date:** [March 14, 2006, 12:36am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/44 "2006-03-14T00:36:41Z")
> [@](#): > > It was completely arbitrary. I was just giving an example of a typical case. Gotcha. I had interpreted it as a sort of rule of thumb. > [@](#): > > I’m not sure anyone fully understands the PSC, including Cracraft himself. 😉 Nor the BSC, for that matter, including the late lamented Ernst. I was simplifying for the sake of this thread. I don’t really want to get involved in a discussion of the pros and cons of the PSC and BSC here. I disagree. As concepts, they are understood. They are both built on artificial rules, so they can be understood. > [@](#): > > Which makes the PSC just about as weak in practice as the BSC is alleged to be. Is there weakness in saying “this could be the case, let’s look further?” If anything, I think there is more weakness in “these guys reproduce. Done, and done.” The BSC is a convenience. > [@](#): > > I know how to describe a species, thank you very much. A lot of biologists know what they’re doing, thank you very much. That doesn’t mean they’re right. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 14, 2006, 12:45am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/45 "2006-03-14T00:45:24Z")
> [@Tourt Eroglik](#): > > I’m not so sure you should be attempting to describe a species of bird if you don’t see how the BSC ignores history. It is a non-dimensional species concept. And the PSC ignores gene flow. Both concepts have their pros and cons. I would point out, however, that most biologists still favor the BSC (and most species are described on that basis), even if a vocal minority (mostly museum-based, most of whom don’t work with organisms in nature) promote the PSC. The majority of species descriptions of birds I have seen recently address both the BSC and PSC aspects (which I will do as well). However, I have the impression that “pure PSC” species of birds are rarely published anywhere but in house journals where the authors have an “in.” > [@](#): > > No, but governments and lawmakers do. That is why species concepts are important. Actually, a very good point, and in practical terms a major benefit of the PSC is all the splitting it would entail. However, a nineteenth-century type Morphological Species Concept would do that pretty much as well ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [March 14, 2006, 12:48am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/46 "2006-03-14T00:48:53Z")
The problem with a real scientist brawl on these boards is that in about three more posts, 80% of us are no longer even going to understand the argument. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 14, 2006, 12:53am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/47 "2006-03-14T00:53:26Z")
> [@Tourt Eroglik](#): > > I disagree. As concepts, they are understood. They are both built on artificial rules, so they can be understood. That was what is known as a “joke.” 😉 > [@](#): > > Is there weakness in saying “this could be the case, let’s look further?” If anything, I think there is more weakness in “these guys reproduce. Done, and done.” The BSC is a convenience. Like I said, both concepts have their pros and cons. I plan to address both concepts in my description. I would feel better about it if I had the evidence that it is both a PSC _and_ a BSC species. It is clearly morphologically and genetically distinctive; but I really would like to find out what happens in the contact zone with other populations, where we have no data. > [@](#): > > A lot of biologists know what they’re doing, thank you very much. That doesn’t mean they’re right. When it comes to species concepts, of course nobody is “right.” Species are human constructs, defined to simplify the complexity we find in nature. I don’t think the PSC is _wrong_, just that they’re “cheap” species. I’d rather have a species that hits on all cylinders. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 14, 2006, 12:55am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/48 "2006-03-14T00:55:45Z")
> [@tomndebb](#): > > The problem with a real scientist brawl on these boards is that in about three more posts, 80% of us are no longer even going to understand the argument. I for one will do my best to make sure that happens. 🙂 ---
**Author:** ![Tourt\_Eroglik](https://avatars.discourse-cdn.com/v4/letter/t/977dab/32.png) [@Tourt\_Eroglik](https://boards.straightdope.com/u/Tourt_Eroglik)\ **Post date:** [March 14, 2006, 1:07am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/49 "2006-03-14T01:07:29Z")
> [@Colibri](#): > > When it comes to species concepts, of course nobody is “right.” Species are human constructs, defined to simplify the complexity we find in nature. I don’t think the PSC is _wrong_, just that they’re “cheap” species. I’d rather have a species that hits on all cylinders. Fair enough. I think we actually agree on most things. But, the BSC hits on all its cylinders because those are the cylinders it uses. It opts to ignore the history cylinder, that’s all. Anyway, I guess this is enough for this on the SDMB… we could argue for ages about this. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 14, 2006, 2:06am UTC](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047/50 "2006-03-14T02:06:17Z")
> [@Tourt Eroglik](#): > > Anyway, I guess this is enough for this on the SDMB… we could argue for ages about this. Yeah, I’d rather save my energy for arguing with the reviewers and editors. 🙂 [Previous page](https://boards.straightdope.com/t/biological-taxonomy-and-race/348047.md?page=2)