PDA

View Full Version : Biological taxonomy and 'race'


LucyInDisguise
03-12-2006, 10:50 AM
Inspired by this thread (http://boards.straightdope.com/sdmb/showthread.php?t=362468), I really am curious about this.

If I recall, our taxonomy goes something like this:

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Genus: Homo
Species: Sapiens

In the real life world of biology, IIRC from my long ago biology classes, there isn't anything like "race" in the system of Taxonomy (http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDivers_class.html#The%20Kingdoms).

Or am I wrong? Do wolves, bacteria and butterflies have 'races'? (And if they do, who'd win?)

Seriously, are 'races' purely a social construct unique to Homo Sapiens? Or is this a term that is used to brake down other species into separate smaller groups? If so, what are they? Is this a practice that is more or less univerally accepted by and used by biologists around the world?

Thanks.

Lucy

II Gyan II
03-12-2006, 11:29 AM
There aren't any rigid subdivisions of humans into 'races', but geographical isolations and selective breeding, have led to fuzzy subsets (http://www.pubmedcentral.gov/articlerender.fcgi?tool=pubmed&pubmedid=15625622).

Colibri
03-12-2006, 11:33 AM
In scientific usage, "race" corresponds to subspecies - populations of a species that can be distinguised by morphological or other characteristics from other populations of the same species. In informal use, biologists frequently use "race" as synonomous with subspecies.

However, the taxonomic category of subspecies itself is not well defined. In the past, subspecies were frequently named on the basis of minor regional variantions, but that practice is now frowned upon.

Subspecies are best defined on the basis of several different characteristics that vary in a coordinated fashion, and where these correlated differences are stable over large areas but change abruptly over a limited area where the ranges of two populations meet. Such populations probably represent groups that were formerly separated and developed differences in isolation, but have now come together again. However, these differences are not enough to prevent free interbreeding in the contact zone, so that these populations are regarded as part of the same species.

Some characteristics may change gradually over a species' range rather than abruptly in a contact zone. Such characters are called "clinal." In the past, subspecies were often named on the basis of clinal characters (especially when data was lacking for intermediate areas), but under modern standards that is not regarded as being valid. This is particularly true when different clinal characters do not show concordant variation. For example, a species may be larger in the north and smaller in the south, and darker in the east and lighter in the west. In the past, taxonomists might recognize a large dark subspecies in the northeast, a small dark subspecies in the southeast, a large light one in the northwest, and a small light one in the southwest. Such subspecies would not be recognized under modern standards.

Most variation in humans is clinal and discordant. According to present taxonomic standards, there would be no basis to recognize subspecies, or "races" in the biological sense. Although local populations may differ in some characteristics, they do not do so in a taxonomically recognizable way. "Race," as far as humans go, is a social construct.

tomndebb
03-12-2006, 11:36 AM
On page 14 of the .pdf at NOMENCLATURE
AND TAXONOMY (http://media.wiley.com/product_data/excerpt/61/04712739/0471273961.pdf) (from Wiley publishers, but I am not sure of the source),
they present a list of what the splitters have manged to wedge into the original seven (eight with the new supercategory "Domain") categories we were taught in high scool biology.
Domain: Eucarya
Animals Plants
Kingdom Kingdom
Subkingdom
Phylum Division/Phylum
Subphylum Subdivision
Infraphylum Infradivision or Branch
Superclass
Class Class
Subclass Subclass
Infraclass
Supercohort
Cohort
Superorder Superorder
Grandorder
Mirorder
Order Order
Suborder Suborder
Infraorder
Superfamily
Family Family
Subfamily Subfamily
Tribe Tribe
Subtribe
Genus Genus
Subgenus Subgenus
Section
Subsection
Series
Subseries
Species Species
Subspecies; or Race, Breed Subspecies
Form Variety
Infrasubspecies; or Race Subvariety
Breed, Form Form
Subform
Cultivar

Note that in the Animal Kingdom, the splitters cannot even agree on where to place Race, Breed, and Form, but (apparently) some splitters have used those terms.

LucyInDisguise
03-12-2006, 12:03 PM
(snip) ... Most variation in humans is clinal and discordant. According to present taxonomic standards, there would be no basis to recognize subspecies, or "races" in the biological sense. Although local populations may differ in some characteristics, they do not do so in a taxonomically recognizable way. "Race," as far as humans go, is a social construct.

(Bolding mine) Thanks, Colibri, that is precisely the answer I was looking for.

tomndebb, thanks for your response as well, but - I note that you seem to use the term 'the splitters' (both in this thread and in the other referenced in the OP) in a somewhat less than completely fattering way - what's the beef? (Don't worry, I'm pretty sure I'm on your side ...)

Lucy

tomndebb
03-12-2006, 12:40 PM
Sorry. I didn't mean to imply anything negative about splitters. I take no sides in the splitters/lumpers disputes. In this case, it is pretty clear that a proliferation of sub-categories are more likely to be defined by splitters than lumpers, hence the verb "wedged," but I hold no animus against them.

I suspect that I could easily be either a splitter or a lumper based on the utility to my decisions of the distinctions being made. Not being active in the biological sciences, I am merely an interested observer.

As an example of my own actions as a splitter, I would point to staff discussions regarding irritating posters where I distinguish between those who are deliberately trolling and those who are simply clueless as to how disruptive they are. Lumpers would simply categorize tham all as either trolls or jerks and ban them while I will do enough splitting to give the clueless a few more chances to behave themselves--and then ban them. ;)

jayjay
03-12-2006, 01:19 PM
I'm just amused now by the thought of starting a "Church of the Subgenus" and giving Bob a run for his money...

John Mace
03-12-2006, 01:33 PM
In scientific usage, "race" corresponds to subspecies - populations of a species that can be distinguised by morphological or other characteristics from other populations of the same species. In informal use, biologists frequently use "race" as synonomous with subspecies.

However, the taxonomic category of subspecies itself is not well defined. In the past, subspecies were frequently named on the basis of minor regional variantions, but that practice is now frowned upon.

Subspecies are best defined on the basis of several different characteristics that vary in a coordinated fashion, and where these correlated differences are stable over large areas but change abruptly over a limited area where the ranges of two populations meet. Such populations probably represent groups that were formerly separated and developed differences in isolation, but have now come together again. However, these differences are not enough to prevent free interbreeding in the contact zone, so that these populations are regarded as part of the same species.

Some characteristics may change gradually over a species' range rather than abruptly in a contact zone. Such characters are called "clinal." In the past, subspecies were often named on the basis of clinal characters (especially when data was lacking for intermediate areas), but under modern standards that is not regarded as being valid. This is particularly true when different clinal characters do not show concordant variation. For example, a species may be larger in the north and smaller in the south, and darker in the east and lighter in the west. In the past, taxonomists might recognize a large dark subspecies in the northeast, a small dark subspecies in the southeast, a large light one in the northwest, and a small light one in the southwest. Such subspecies would not be recognized under modern standards.

Most variation in humans is clinal and discordant. According to present taxonomic standards, there would be no basis to recognize subspecies, or "races" in the biological sense. Although local populations may differ in some characteristics, they do not do so in a taxonomically recognizable way. "Race," as far as humans go, is a social construct.
That may be the single best post I've seen on the issue of human races on this board.

And it points out an important point to keep in mind about "race". Many people assume* that different populations of humans evolved into the modern "races" as isolated populations on the various continents for long periods of time and then, only in historical times, began coming together at the boundaries. That's simply not the case. With a few recent exceptions (like The Americas and Tasmania), there has always been gene flow back and forth between the various continents and land masses, and no populations has been truly isolated for an extended period of time. Instead, human populations spread out from Africa some 60k years ago, with variations occuring as this spreading continued around the globe.

Even if we look at the Americas, that period of relative isolation is fairly brief (on the timescale of evolutionary change)-- our best evidence suggest that immigration from Asia started less than 15,000 years ago. And if we were to assume that a period of isolation ensued after the oceans rose at the end fo the Ice Age (as the DNA data suggests), there were still periods of new immigrations (like the ancestors of the Inuit or Eskimos) between then and now.

Looking at the rest of the globe, it doesn't make sense to talk about geographically isolated populations. Europe and Asia form one landmass, East Africa and the Middle East are really one interconnected zone rather than two isolated zones, and even Australia has seen gene flow back and forth between the lands to its north.

*or hold beliefs that implicity assume

Tourt Eroglik
03-12-2006, 01:47 PM
Such subspecies would not be recognized under modern standards.

This is not entirely true. Since a subspecies has no real biological definition, it is all "in the eye of the beholder." There are many studies that still delineate subspecies, despite being clinal in character. It all depends on the nature of the study.

So what are these modern standards?

Gladstone
03-12-2006, 02:09 PM
According to present taxonomic standards, there would be no basis to recognize subspecies, or "races" in the biological sense. Although local populations may differ in some characteristics, they do not do so in a taxonomically recognizable way. "Race," as far as humans go, is a social construct.

Wouldn't the same be true of dogs, cats, horses, and other variations within a single species?

Laughing Lagomorph
03-12-2006, 02:30 PM
Wouldn't the same be true of dogs, cats, horses, and other variations within a single species?

(I'm not sure I completely understand the question, let me know if I am off base...)


Since the three types of animals in your example are generally subject to artificial selection by human beings to select for characteristics we find desirable (or against characteristics we find undesirable) I'm not sure they are the best examples to compare against.
As I'm sure you know different subsets within such species are usually referred to as breeds rather than subspecies.

John Mace
03-12-2006, 02:45 PM
This is not entirely true. Since a subspecies has no real biological definition, it is all "in the eye of the beholder." There are many studies that still delineate subspecies, despite being clinal in character. It all depends on the nature of the study.

So what are these modern standards?
That was Colibri, not me, who posted that. But I agree with him and I think he gave a full explanation to your question in his original post. Keep in mind that there isn't universal agreement (even among biologists) on the rules of taxonomy. It's kind of like spelling English words. If we were starting from scratch we'd do things differently, but there are historical conventions that hand around whether they make sense anymore or not.

Tamerlane
03-12-2006, 03:04 PM
For a quick illustration of Colibri's post I give you two local subspecies of the ensatina salamander:

Ensatina escholtzii oregonensis:

http://www.californiaherps.com/salamanders/images/ensatinakrme05.jpg

and Ensatina escholtzii xanthoptica:

http://www.californiaherps.com/salamanders/images/eexanthopticabr2.jpg
http://www.californiaherps.com/salamanders/images/eexanthopticacubr.jpg

Believe me when I say that any color or morphological variation you see in this photos is purely individual, except the yellow coloration on the upper half of the eyes on the more southern population. Otherwise they are identical in habit, habitat and general appearance. Where their range meets a little north of the SF Bay Area they form nice little "hybrid zone" wherein you can find individuals that have just a slight gold dusting to the upper eyes :).

Ensatinas are a rather more complex species group that just the above, but those two subspecies in particular are a perfect example of common naming conventions in biology. A very non-vagile organism, with relatively modest gene flow between distant populations, wherein a genetic mutation has cropped up in one population coding for one small ( and likely non-adaptive ) physical variation, has been seperated into two taxonomic subgroups by scientists. As a descriptor of population it's handy shorthand. But these are the same critter in every respect except eye color.

- Tamerlane

LucyInDisguise
03-12-2006, 04:29 PM
Thanks for the clarification.

Sorry. I didn't mean to imply anything negative about splitters. I take no sides in the splitters/lumpers disputes. ...(snip)

Nor I. I merely resist splitting where ever practical when arguments bring up "race". I have 2 grandchildren of mixed heritage. Everyone, I should make that nearly everyone else wants to pigeon hole them into some type of "race". It is my firm belief that we should all try to find a way to stop at just the one "race" - the Human Race.

It should be noted that with everything else (as with your example) I'm the worst splitter (read that as nit-picker) on the planet. (Just ask my wife ...)

Lucy

Colibri
03-12-2006, 04:57 PM
This is not entirely true. Since a subspecies has no real biological definition, it is all "in the eye of the beholder." There are many studies that still delineate subspecies, despite being clinal in character. It all depends on the nature of the study.

So what are these modern standards?

What I said above. The modern standard, to the extent that there is one, is to not recognize new subspecies on the basis of clinal characters. Taxonomic revisions these days tend to abolish (that is, recommend not to recognize) previously recognized subspecies that were based solely on clinal variation. Taxonomists who favor the Phylogenetic Species Concept, on the other hand, tend to "promote" non-clinal (phylogenetic) subspecies to species, even if they interbreed and thus are only subspecies according to the Biological Species Concept.

Could you cite a paper in a peer-reviewed journal that recognizes subspecies where the variation is purely clinal in nature? (I dunno, maybe the botanists are still doing that kind of stuff. But they're pretty eccentric in general. :)

I'm in the process right now of describing a new species of bird in Africa that by some standards might be considered a subspecies. Unfortunately I am afraid this is going to embroil me in the PSC-BSC wars.

Colibri
03-12-2006, 05:03 PM
Wouldn't the same be true of dogs, cats, horses, and other variations within a single species?

I presume you are talking about breeds of domestic animals. Since these have been established through artificial selection by humans, they are outside the framework of the taxonomic system. But these breeds do not correspond to human "races" either, since purebreds generally have much more homogeneity than human races.

Tamerlane
03-12-2006, 05:10 PM
I'm in the process right now of describing a new species of bird in Africa that by some standards might be considered a subspecies. Unfortunately I am afraid this is going to embroil me in the PSC-BSC wars.

Since when did they let you off your island to go to Africa :D? And is it at least a sunbird or some other sort of hummingbird analog?

I remember back in the early 1990's when I still followed this stuff closely, Joseph Collins proposed raising 50-odd subspecies to full species based on the ESC. The howls of outrage echoed through journals like Herpetological Review for months. Nice to see nothing has changed in the last decade and a half :p.

- Tamerlane

Tamerlane
03-12-2006, 05:12 PM
I remember back in the early 1990's when I still followed this stuff closely, Joseph Collins proposed raising 50-odd subspecies to full species based on the ESC.

50-odd subspecies of North American herps that is, if it wasn't obvious from the reference.

- Tamerlane

Colibri
03-12-2006, 05:22 PM
Since when did they let you off your island to go to Africa :D? And is it at least a sunbird or some other sort of hummingbird analog?

I did some work in Gabon in 2001-2003. It's a member of the thrushes, but more than that I cannot say until the paper goes in.

However, we found it in Mt. Doudou National Park in Gabon, at a miserable camp in a swamp which we referred to as Deep Doudou. We are contemplating naming it bathydoudouensis. :D

Chronos
03-12-2006, 06:17 PM
OK, I grok the Biological Species Concept (if two critters can and do mate successfully, they're the same species). But what is the Phylogenetic Species Concept, and the ESC, which I presume is some other species concept?

And Colibri, just to make sure I understand your example properly: If the critters to the north were both larger and had lighter colors, and maybe shorter tails, too, while the southern critters were smaller, darker, and long-tailed, but they still freely interbred at the interface, then they would likely be considered different subspecies by the modern standard, correct?

Colibri
03-12-2006, 06:46 PM
OK, I grok the Biological Species Concept (if two critters can and do mate successfully, they're the same species). But what is the Phylogenetic Species Concept, and the ESC, which I presume is some other species concept?

This article (http://www.mscok.edu/~bstewart/bstewart/classes/zoology/species.htm) has a discussion of various species concepts. The ESC is the Evolutionary Species Concept, which is similar to but not exactly the same as the PSC.

Personally, I favor the BSC. However, although we are certain our African bird is a good PSC species, we don't know if it is a good BSC species.

And Colibri, just to make sure I understand your example properly: If the critters to the north were both larger and had lighter colors, and maybe shorter tails, too, while the southern critters were smaller, darker, and long-tailed, but they still freely interbred at the interface, then they would likely be considered different subspecies by the modern standard, correct?

It depends on how the characteristics changed and how they were correlated with one another. If, say:

1) The northern population were all large, light, and short-tailed, and these characters did not vary systematically over a 1000 km of this form's range

2) The southern were all small, dark, and long-tailed, and these characters did not vary over 1000 km of this forms range

3) In the area where these two met, there was a hybrid zone of perhaps 50 km where these two forms freely interbreed and produced intermediates.*

Then, according to the BSC, they would be subspecies of the same species. According to the PSC, they would be separate species, since the PSC doesn't care about interbreeding. By the PSC, the two forms would be "diagnosable" across most of their ranges and thus be good PSC species.

If, however, the characters varied gradually over the range of the species, so that there was no point at which one could draw a clear demarcation between the populations, then by modern standards they would not be accepted as subspecies by either the BSC or PSC.

*If hybridization occurred but was rare or limited in this zone, the BSC would consider them to be full species.

DrDeth
03-12-2006, 08:35 PM
Colibri's write up about subspecies is pretty darn good. For other reasons, scientists no longer use the term "race" in application to Humans. And "breed" is right out. Population is the now accepted term. The old "races" have been shown to have very little to do with genetics- those dark skinned people once lumped together as "Negroid" are members of many different Populations anyway- the Australian Abo is no more part of the same Population of a Masai than I am. The Australian Aborigines are a good example of a Population, BTW. If you think of a Population as a Tribe or group of tribes you will come close, but that's not really right, either (some Tribes are indeed Populations, true, but not all, and the lines aren't always along tribal borders, either)

Other that various pre-historic Humans*, we also don't split Humankind into Subspecies either. True, extreme "splitters" could possibly argue that some Populations are Subspecies, but in general, biologists "don't go there". The defintion of a subspecies is rather fuzzy and not 100% agreed upon, and Humans move around a lot, anyway.


*and there is disagreement even there. Is Neanderthal Man Homo Sapiens Neanderthalis? Or Homo Neanderthalis? Species or Sub-species? Maybe even neither? :confused:

LucyInDisguise
03-12-2006, 09:56 PM
DrDeth, Colibri, your two are my new heroes. I'm definitely getting my nickel's worth out of this.

So, DrDeth, if I understand correctly, the term Population has supplanted the term race in describing Human Beings - at least as far as the strict sciences go, correct?

How far behind, in your opinion, will social scientists be before they are willing to recognize this?

Lucy

John Mace
03-12-2006, 10:08 PM
*and there is disagreement even there. Is Neanderthal Man Homo Sapiens Neanderthalis? Or Homo Neanderthalis? Species or Sub-species? Maybe even neither? :confused:
Most anthropologists say "species", by quite a large margin. However, at the very least Neanderthals would qualify as a subspecies. The line leading to them and the line leading to us split about 500,000 years ago, and the two populations were probably isolated from each other to a large extent. That would be plenty of time to earn the subspecies status.

(And you'd write it neanderthalensis, whether as a species or subspeicies name.)

tomndebb
03-12-2006, 10:37 PM
the term Population has supplanted the term race in describing Human Beings It is not so much that one has supplanted the other as that we recognize that "race" has no useful meaning (as it originally was used to describe a great many diverse groups based on some arbitrarily chosen similarities) while "population" identifies much smaller groups for which we can assemble actual facts regarding genetics, descent, kinship, etc. For example, the discussions about better athletic performance by "race" generally includes a mention of the Kenyan marathon runners, most (all?) of whom are actually from a smaller fairly well-defined population of people known as Kalenjin (http://en.wikipedia.org/wiki/Kalenjin). There is no legitimate way to equate this specific ethnic group (population) of fewer people than live in Chicago with a "race."

The one term did not replace the other so much as the discussion moved to a better and more accurate way to examine issues.

Colibri
03-12-2006, 11:13 PM
if I understand correctly, the term Population has supplanted the term race in describing Human Beings - at least as far as the strict sciences go, correct?

tomndebb has pretty well summed up the situation as far as biology goes. Plants and animals in general can be talked about in terms of populations; in some cases the kind of variation shown between some populations can be categorized in terms of subspecies (or race, in the technical biological sense). Humans do not show the kind of variation that merits recognition as subspecies, so it is inappropriate to use the term "race" with respect to this variation.

How far behind, in your opinion, will social scientists be before they are willing to recognize this?

Well, "race" does have some sort of meaning in the social sense. Certainly "race" is recognized in US society. It is, however, important to realize that race in this sense is a social construct (as has been said before), and does not correspond at all to its biological meaning. It has more meaning as an ethnic/social category than anything else.

Tourt Eroglik
03-13-2006, 12:39 AM
Personally, I favor the BSC.

Why? It ignores history. What are the advantages of the BSC that make you favour it?

Tourt Eroglik
03-13-2006, 12:54 AM
Could you cite a paper in a peer-reviewed journal that recognizes subspecies where the variation is purely clinal in nature?

Sure could. Can you wait until morning?

Not sure why it's needed, though. I think you might be ignoring step clines, in which the "plateaus" are often assigned subspecies status, though. Not all clines are linear, which do indeed pose a problem as to where the delineation should be.

Tourt Eroglik
03-13-2006, 01:24 AM
1) The northern population were all large, light, and short-tailed, and these characters did not vary systematically over a 1000 km of this form's range

Then, according to the BSC, they would be subspecies of the same species. According to the PSC, they would be separate species, since the PSC doesn't care about interbreeding. By the PSC, the two forms would be "diagnosable" across most of their ranges and thus be good PSC species.

Where did you get this 1000km figure?

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.

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.

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.

DrDeth
03-13-2006, 10:29 AM
Most anthropologists say "species", by quite a large margin. However, at the very least Neanderthals would qualify as a subspecies. The line leading to them and the line leading to us split about 500,000 years ago, and the two populations were probably isolated from each other to a large extent. That would be plenty of time to earn the subspecies status.

(And you'd write it neanderthalensis, whether as a species or subspeicies name.)

You're right, I spelled it wrong. Spellchecker didn't help!

I vote "subspecies" myself, but honestly, there's too much guesswork for pre-historic species to be absolutely sure.

LucyInDisguise, you are more or less correct. "Race" still has some validty for the Social Sciences; but even there, lumping people together primarily on skin color is still wrong, IMHO. Even for the Social sciences, there should be at least 4 "black races" (note, I don't like that term, but :( ) But Colibri & Tomndebb did all the hard thinking here, I just tried to make the terms a little simpler for a layman. Colibri is 100% in saying that other animal species also have "populations"- there the term is often used to describe a grouping in a species that doesn't rise to Subspecies. This is correct for Homo Sapiens- that species has no current extant subspecies. I am not even going to put "IMHO" there as I can't think of any legit scientists that claims current sub-species of Homo Sapiens.

John Mace
03-13-2006, 01:07 PM
I vote "subspecies" myself, but honestly, there's too much guesswork for pre-historic species to be absolutely sure.
[B]
It's not so much about voting and guessing as it is about choosing a model and coming to a conclusion from the available evidence, of which there is quite a bit. Using the BSC, as I think most biologist do, there is a strong case to be made for putting Neanderthals in a seperate species. They were a morphologically distinct, largely isolated population which, even if they could interbreed with Sapiens, appeared to have done so only on rare occasions.

Not that Mother Nature really cares one way or another how many discrete boxes we humans arbitrarily put around the continuum of life that She has laid out in front of us. :)

Tourt Eroglik
03-13-2006, 01:25 PM
Using the BSC, as I think most biologist do,

Are botanists no longer considered biologists, then?

You guys have probably had this already, but perhaps a thread regarding species concepts is in order.

Tourt Eroglik
03-13-2006, 01:27 PM
Not that Mother Nature really cares one way or another how many discrete boxes we humans arbitrarily put around the continuum of life that She has laid out in front of us.

No, but governments and lawmakers do. That is why species concepts are important.

Tamerlane
03-13-2006, 01:39 PM
Are botanists no longer considered biologists, then?

Pfft! Just a bunch of party animals in my experience :D.

But I tend to agree - the BSC is dieing most everywhere except maybe among the endotherm folks. It was on its way out with herpetologists a decade or two ago and none of the arachnologists I hang out with these days use it either ( I did use to know a couple of hardcore utilitarian pheneticists, but I don't think they are active anymore ).

By the way, I'm sure Colibri is more than experienced in species descriptions - he's been doing this for awhile I believe. But for myself I remember thinking Brooks & McLennan's book Phylogeny, Ecology and Behavior was pretty neat.

*sigh* Maybe I should get back into reading biology again.

- Tamerlane

John Mace
03-13-2006, 02:46 PM
Are botanists no longer considered biologists, then?

You guys have probably had this already, but perhaps a thread regarding species concepts is in order.
I don't know much about botanists, so I should have said "most anthropologists".

No, but governments and lawmakers do. That is why species concepts are important.
Now, that is an interesting subject. Nothing like getting lawmakers and activists involved in the scientific process!

I've actually seen at least one anthropologist suggest a political reason for calssifying Neanderthals as a subspecies. IIRC, the argument was based on staking out that ground for the Neanderthals so that no one could use it (subspecies = race) for any extant human population.

Blake
03-13-2006, 05:40 PM
.... the Australian Abo is no more part of the same Population of a Masai than I am.

Ahem.

I realise you were just trying to use it as an abbreviation, but you have commited a major fox paws. The word "Abo"is highly offensive and derogatory. While perhaps not quite as bad as 'nigger' it is directly equatable with 'spic' or 'wetback' and should never be used unless you intend to be offensive.


The Australian Aborigines are a good example of a Population, BTW.

Only to a slightly lesser degree than "European" is a population. Aborigines are nither genetically nor phenotypically uniform nor have they ever been isolated for extended periods. Europeans form a afr more homogeneous population than Aborigines.

DrDeth
03-13-2006, 06:01 PM
Ahem.

I realise you were just trying to use it as an abbreviation, but you have commited a major fox paws. The word "Abo"is highly offensive and derogatory. While perhaps not quite as bad as 'nigger' it is directly equatable with 'spic' or 'wetback' and should never be used unless you intend to be offensive.



Noted. I had no idea, honestly. Thought it was just short for Aborigine- which I understand isn't all that PC now a days either, but it seems that no 'racial" term is, anyway.

Blake
03-13-2006, 06:22 PM
Noted. I had no idea, honestly.

I know. Just a heads up for avoiding future cultural misunderstandings.


Thought it was just short for Aborigine- which I understand isn't all that PC now a days either, but it seems that no 'racial" term is, anyway.

Given that Australians love contracting any word over 2 syllables it probably did start out as a short form of Aborigine, but the context has changed over time and it is now definitely not acceptable.

Aborigine is still perfectly acceptable, although "Aboriginal Australian" is probably more "PC' as you put it.

Colibri
03-13-2006, 07:08 PM
Why? It ignores history. What are the advantages of the BSC that make you favour it?

No, it doesn't ignore history at all. It merely considers present gene flow to be more significant in defining species.

Biffy the Elephant Shrew
03-13-2006, 07:18 PM
Note that in the Animal Kingdom, the splitters cannot even agree on where to place Race, Breed, and Form, but (apparently) some splitters have used those terms.
You mean to say that with all those categories they still don't know where to phylum?

Colibri
03-13-2006, 07:23 PM
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. :)

Tourt Eroglik
03-13-2006, 07:30 PM
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.

Colibri
03-13-2006, 07:30 PM
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. :D

Tourt Eroglik
03-13-2006, 07:36 PM
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.

Colibri
03-13-2006, 07:45 PM
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

tomndebb
03-13-2006, 07:48 PM
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.

Colibri
03-13-2006, 07:53 PM
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.

Colibri
03-13-2006, 07:55 PM
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. :)

Tourt Eroglik
03-13-2006, 08:07 PM
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.

Colibri
03-13-2006, 09:06 PM
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. :)