# Anatomy of a scientific name



## Cavan Allen (Jul 22, 2004)

There have been a few questions about scientific names recently, so I thought I'd start a thread on the subject. I realize that many of you already know the following, but a good refresher never hurts.

We'll use the following example:

_Ludwigia_ l _inclinata_ l var. l _verticillata_ l 'Cuba'

_Ludwigia_ - This is the genus name. All species sharing the same basic characteristics are grouped thusly. The genus name is both capitalized and italicized.

_inclinata_ - This is the species name. It is also italicized but is not capitalized like a person's last name would be. A species is a group of interbreeding organisms that do not breed with other similar organisms.

var.- Variety. This is short of being a subspecies (different from the type or original specimen). The species in question is very variable in terms of leaf arrangement, with alternate leaves in the typical type and verticillate (or whorled) leaves in this one. Variety (var) is a botanical designation and does not apply to things like 'red' or 'Pantanal'. This part of the name is not italicized (thank you Dennis).

'Cuba' - Often mistakenly given parenthesis, this part of a name refers to a local form of the species that does not meet subspecies or variety status. It is not italicized, and is basically a common name attached to the end. When the species name is not known, it is often used in place of the species name. An example of that is _Limnophila sp_. 'Mini'.

The plural of genus is genera. Like genera are grouped into families. _Ludwigia_ species are in the family Onagraceae (families are not italicized).

That's it for now. Any questions?


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## BryceM (Nov 6, 2005)

I have one question:

Who is the keeper of the names? In other words, who is "the" official source when it comes to assigning these?

My understanding is that the person or group who originally described the species is able to suggest a name for genus & species. When disputes or new data arises, who gets the final say regarding further naming?

For example, _Pogostemon stellatus _is a species that we're all familiar with. I'm guessing that at some point a person "discovered" a new variety and suggested the name of _Pogostemon stellatus 'Broad'_. Who gets the final say about whether or not this is really a new species, a subtype, or a variation? Also, who decided it was _Pogostemon stellatus_, and not _Eusteralis stellata_?


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## AndyT. (Jun 28, 2006)

I have a question about hybrids... or what I think are hybrids.

When I see something like _Echinodorus bleheri v. robustus_ is the "v." between species names the same as the "var."? In other words would the name _Echinodorus bleheri v. robustus_ be synonymous with _Echinodorus bleheri var. robustus_? Is the "robustus" an actual species name or what does it actually designate? Or is this a cross between two species of swordplant?

Another question in the same vein...
_Echinodorus x barthii _ - what does the "x" designate here?

Last one, I promise. _Eusteralis stellata (Pogostemon stellata)_ - in this case, the name in parenthesis is an outdated name and has been replaced by the name in front, correct?

Thanks for this thread. This has been bugging me for a while!


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## bigtroutz (Nov 17, 2006)

guaiac_boy said:


> I have one question:
> 
> Who is the keeper of the names? In other words, who is "the" official source when it comes to assigning these?
> 
> ...


There is no official keeper of scientific names. Group names are arrived at by consensus, although individual scientists are free to be gadflies.

Taxonomists (scientists who attempt to decern species from populations) range from "lumpers" to "splitters"; that is, those who clump morphologically similar species together or split different specimens into widely spread taxons. [Genetics has thrown even more of a monkey wrench into the works, btw].

Periodically some specialist in a group of species/genera/family reviews all known type specimens as well as additional specimens and attempts a revision of the group's taxonomy, often on the basis of comparative anatomy. Since additional species may have been described since an original specimen was described as a species, intermediate characteristics have been discovered and 'relationships' inferred. Often, cladistics is employed in these efforts. Cladistics - Wikipedia, the free encyclopedia

BTW, a species is defined as an effectively self contained breeding population - it can be separated from a closely related species by space or time as well as the failure for corssbreeding to produce viable offspring. For instance, some would argue that Asian brown bears are a separate species from North American grizzly bears because they are effectively isolated breeding populations even though they may interbreed in captivity.

All of this is a human effort to group populations of animals based on their evolutionary responses to their environment. The species themselves don't give a dang; they just continue do do their own thing, rofl.


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## dennis (Mar 1, 2004)

Traditionally the x stands for cross or hybrid. The name is the name of the hybrid, and generally has nothignto do with the names of the original crossed species.

Yes, to my knowledge the v. stands for var. It should not be italicized nor should the name after it. These names, in this case robustus is like trade name of a location name for an unknown species.


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## bigtroutz (Nov 17, 2006)

AndyT. said:


> I have a question about hybrids... or what I think are hybrids.
> 
> When I see something like _Echinodorus bleheri v. robustus_ is the "v." between species names the same as the "var."? In other words would the name _Echinodorus bleheri v. robustus_ be synonymous with _Echinodorus bleheri var. robustus_? Is the "robustus" an actual species name or what does it actually designate? Or is this a cross between two species of swordplant?
> 
> ...


"V" is short for variety or variant and is approximately equivalent to 'race' or subspecies. It is also used in plants for human induced morphs or cultivars. If the genus and species names are identical, then the presumption is that the variants can be found in nature in one interbreeding population.

"X" can be short for a human induced cross between species that presumably would not occur in natural populations.

In your last question, a taxonomist has engaged in a revision in a family of plants and has decided that this particular species 'stellata' belongs in the genus 'Eusteralis', This could mean that the genus 'Pogostemon' has been split into 2 or more genera or that 'Pogostemon' equals 'Eusteralis', which is something I do not know, not being a plant taxonomist.


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## John N. (Dec 11, 2005)

*What does the "sp." stand for?*

"sp" refers to...? For example, _Ludwigia sp._ 'Guinea'

-John N.


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## ed seeley (Dec 1, 2006)

Var. is an abrreviation of varietas (latinised for variety)

Sp. is where it is thought to be an undescribed sp.

ssp. is a subspecies.

spp. is more than one species - used in certain circumstances.

A subspecies is at a different level of differentiation to a variety and usually indicates a relatively significant difference. There is an awful lot of confusion as to what determines a species/subspecies/varietas/form (_f_) and cultivar(usually non-italisised in quotation marks) but all COULD be used as they are supposed to represent different layers of differentiation - e.g. you could have _Apistogramma cacatuoides ssp. cacatuoides var. rubra f. rubra_ 'Triple Red'! Obviously this would be VERY VERY uncommon!

Usually the different 'levels' of classification are more often used in plants where two or three levels being used to describe specimens not being as uncommon. I have a little hardy geranium called _Geranium sessiliflorum ssp. sessiliflorum var. nigricans_ 'Little Black'! And it's a tiny little plant too, unlike it's name!

the 'X' can apply to natural hybrids too, not just man-made ones. If they then reproduce with themselves they could form a new species that would then recieve a more standard description! This is often seen in plants where it is believed that many 'species' were formed by hybridisation between two others - Marram grass (on sand dunes!) is a believed example of this!

Got to remember they are labels we stick on things!


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## ed seeley (Dec 1, 2006)

PS. I would doubt the validity of the species _Eusteralis stellata_ as an 'official' name change as the species name should be the same gender as the Generic name, e.g. _Pogostemon stellata_, but _Eusteralis stellatus_. They should be changed when a species is re-assigned to a new genus.


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## Cavan Allen (Jul 22, 2004)

AndyT. said:


> I have a question about hybrids... or what I think are hybrids.
> 
> When I see something like _Echinodorus bleheri v. robustus_ is the "v." between species names the same as the "var."? In other words would the name _Echinodorus bleheri v. robustus_ be synonymous with _Echinodorus bleheri var. robustus_? Is the "robustus" an actual species name or what does it actually designate? Or is this a cross between two species of swordplant?


That may be a valid race of _E. bleheri_. It would not be a hybrid.



> Another question in the same vein...
> _Echinodorus x barthii _ - what does the "x" designate here?


As others have pointed out, it denotes a hybrid. Also worth pointing out is that in hybrids where both parent species are known, it matters which parent species is named first. For example, _Ludwigia repens x arcuata_ would not be the same as _L. arcuata x repens_. Whichever is named first has its flower pollinated by the pollen of the latter.



> Last one, I promise. _Eusteralis stellata (Pogostemon stellata)_ - in this case, the name in parenthesis is an outdated name and has been replaced by the name in front, correct?


Actually, the correct name is _Pogostemon stellatus_. At some point in time, someone took a plant that had already been named and assigned it the name _Eusteralis stellata_. The name given first takes precedence. This same kind of thing can be seen with the dinosaur genus _Brontosaurus_. _Apatosaurus_ is in fact the proper genus name because material for it was described earlier. The spelling of the species name changes depending on to which genus it is assigned.


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## Cavan Allen (Jul 22, 2004)

> "V" is short for variety or variant and is approximately equivalent to 'race' or subspecies. It is also used in plants for human induced morphs or cultivars.


var is not used for man-made morphs or cultivars.


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## AaronT (Apr 26, 2004)

John N. said:


> "sp" refers to...? For example, _Ludwigia sp._ 'Guinea'
> 
> -John N.


To elaborate on what Ed already said the "sp." in a name is short for species.

For example, _Hygrophila sp._ 'Tiger' reads outloud as hygrophila species tiger.


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## AndyT. (Jun 28, 2006)

Thank you all for clarifying this... I am definately subscribing to this thread as I anticipate referring back to it. I was pretty clear on genus and species, but after that my understanding broke down rapidly.

Great thread Cavan!


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## Stephan K. (Apr 30, 2006)

_Echinodorus bleheri _isn't the correct name. This plant was renamed to _E. bleherae_, because Rataj named the plant after Amanda Bleher. So the ending of the name was not correct.
In this case the name has to be changed.

Stephan


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## Satirica (Feb 13, 2005)

Thank you for this very useful thread! It's been a long time since high school biology.


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## bigtroutz (Nov 17, 2006)

Cavan Allen said:


> var is not used for man-made morphs or cultivars.


Your statement is correct as is mine; it's a matter of definition and convention:
- The above assumes you are dealing with "plants"; animal naming conventions are different and set by different groups.

- The above assumes the namer adheres to the guidelines set by certain botanical organizations, such as the ICBN. Some don't. The rules set by organizations like the ICBN have no force of law; nobody is going to arrest and prosecute an offender, rather they act as convention which is frequently broken intentionally, thru ignorance, or because the naming occurred prior to a rule change by such a body.

- The above assumes that the cultivar is not a naturally occurring variety (in the strict sense) selected and then cultivated, even when the namer adheres to the rules set by bodies like the ICBN.

All of this is splitting hairs.

For our purposes here, variety is equivalent to race, cline, subspecies, morph, subpopulation, clone line, whatever, namely a variant of a species with some particular attribute that allows it to be arbitrarily separated from the rest of the individuals of that species.

It is usually arbitrary because the incidence of such variations typically at present or in the past form(ed) normal curves (see below) without discontinuities useful in that separation.









For instance, let's say that a plant variety is named because its leaf color is bronze as opposed to the more typical green. If enough specimens are measured, the 'bronzeness' turns out to be a portion of normal curve for the relative abundances of the various pigments. The presumption is that there is some genetic mechanism controlling the relative pigment concentrations.


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## Cavan Allen (Jul 22, 2004)

So because some people use the designation incorrectly we should continue doing it? I don't follow.

Variety is a botanical designation like species, genus and subspecies. It is supposed to apply to naturally differing plants. For our purposes, isn't it sufficient to use the following format?

_Cryptocoryne wendtii_ 'green'


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## Robert Hudson (Feb 5, 2004)

"sp" is also used when the sub specie is unknown, or unverified, when a speciment is collected and and the varient found has not been confirmed as anything but the family name. This is common by various plant farms and nurseries, particularly in Asia. While some plant farms may assign the locale into the name, others feel it is more of a standard to simply use "sp"

This is how we have all these different names by location for Toninas, Ludwigias and so forth, and why it has gotten so confusing to people. A company like Rayon vert just arbitrarily assigns names to these plants.


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## bigtroutz (Nov 17, 2006)

My point is that any format you decide is sufficient is arbitrary to a lesser or greater extent.

The important concepts are those underpining the concept of a species, how we decide what a species is, and how that species is related to those from which it descended and which descended from it, should they exist.

The labels we assign (Order/Family/Genus/Species/Subspecies) are conveniences as are the conventions associated with the labels. The most arbitrary label of them all, in many ways, is the one associated with subspecies/race/cline/morph/variety/whatever since, by definition, they are evanescent, artifacts or in the eye of the beholder. 

All individuals in a population, even clones (human twins are clones), show genetically based variation. Your own genetic makeup will vary through time because of transcription error and mutation (eg cancer). 

All species will form variants on the basis of these genetic variations and selective pressure. This is what we call evolution and variation within a species is evolution in action. 

We can call intraspecific variability any name you like but it is all the same thing regardless of whether the selective agent is **** sapiens, Alces alces (moose), or salinity. Segregating out human induced variation from other selective pressures is merely hubris.


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## BryceM (Nov 6, 2005)

"A rose by any other name........"



I think that, at least, we can all agree that using scientific names is far better than "common" names. One person's "baby tears" is not the same as the next guy's.


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## ed seeley (Dec 1, 2006)

Robert Hudson said:


> This is how we have all these different names by location for Toninas, Ludwigias and so forth, and why it has gotten so confusing to people. A company like Rayon vert just arbitrarily assigns names to these plants.


I'm afraid that most of the time this can merely be a convenient marketing ploy! If you have a 'new' specimen to offer to your buyers then they are likely to snap it up to give it a try, whereas if you simply offer a new collection of the same, old thing then your market will be much smaller. This is as true for the garden horticultural world, where a very famous seed company has for years marketed 'new' discoveries or forms that are simply renamed strains that have been grown for years! It used to be a source of constant irritation to the specialist horticulturalists who had been growing and selling them for years under their real names!

I think regardless of what name is used there will always be this, and other problems, for any naming system. Whether scientific names or common names are used there will be mis-named specimens. At least with aquatic plants, which are almost always propogated vegetatively, you don't often have the problem of breeding different things together and getting hybrids that are then sold as ANOTHER 'new species'!


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## Cavan Allen (Jul 22, 2004)

Robert Hudson said:


> "sp" is also used when the sub specie is unknown, or unverified, when a speciment is collected and and the varient found has not been confirmed as anything but the family name.


That's true, but the singular and plural of species is the same. Specie refers to coin money.


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## Cavan Allen (Jul 22, 2004)

bigtroutz said:


> My point is that any format you decide is sufficient is arbitrary to a lesser or greater extent........................................
> 
> We can call intraspecific variability any name you like but it is all the same thing regardless of whether the selective agent is **** sapiens, Alces alces (moose), or salinity. Segregating out human induced variation from other selective pressures is merely hubris.


It is often the case that the splitting of species themselves could be considered arbitrary. Where people draw the line is often the issue. I don't agree that segregating human-induced variations from natural ones is hubris anyway. Variety is meant to seperate natural races of a particular species and, in my opinion, does not constitute improper imposition of human labels on the natural world. Feel free to disagree.

As an aside, names like _Alces alce_s or _Badis badis_ are not permitted for plants per the rules of nomenclature.


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## bigtroutz (Nov 17, 2006)

Naming species is *always* arbitrary.

Prior to the use of genetics in taxonomy (which consists of over 95% of existant species naming) systematists primarily used morphological differences to separate species from one another. The presumption is and always has been that the morphological differences observed reflected underlying genetic differences large enough to reflect a difference between species. In actuality, the presumption may or may NOT be correct. Not too many scientists follow individual fungus gnat breeding habits nor document the probabilities of successful pollination and subsequent viable seed production across an entire population of pond lillies, for instance.

Even with todays state of genetics, separating species is problematic because we do NOT have a complete enough understanding of the roles played by ALL of the genetic material replicated in germ cells nor of the role played by polyploidy which is extensive in plants on evolutionary biology

The concept of species becomes extremely tenuous in asexually reproducing organisms like bacteria where cross species/genera/family exchange of genetic material is commonplace. The incorporation of one organism into another as endosymbionts is another monkey wrench thrown into the works eg. Are animals and plants one species or a cluster of cooperating species ?

If you wish to delve further into the definition of a species and the difficulties involved, this link gives a pretty good discussion:
Species - Wikipedia, the free encyclopedia

Are humans somehow not natural ? Are we not animals and members of the 'natural' world? Hubris is thinking we are better/above it all somehow. Varieties created by man are the same as varieties created by 'natural' processes because man is just another 'natural' process and a variety is simply a subpopulation of a species.


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## ed seeley (Dec 1, 2006)

Generally the consensus in plant nomenclature (of those grown out of water anyway where i have a bit more experience!) is that cultivar names are applied to man made selections and those selections have little genetic diversity. Indeed they are almost always vegetatively propagated. This means that if you have a cultivar of a certain plant, e.g. _Hamamelis x intermedia_ 'Pallida' (the Witch Hazel which is about to look sooo good in my garden at any moment!), all of these plants are clones of the original (unless further somatic mutation has occured since) e.g. every single one is propagated by grafting them onto a rootstock.

These cultivar names are sometimes applied to seed strains but these should be strains that breed true to give offspring with very little obvious variation. For this reason these artificially similar results are inherently 'man-made' and would not occur in nature. _Microsorum pteropus _ 'Windelov' is as close to an aquatic analogy i can think of.

Thus, IMO, there is an inherent difference between natural variation being described by people (by the use of the various 'levels' of specification) and the systematic breeding of a plant, or a plant's propagation and distribution in the hobby after discovery. The plants in our hobby are much more analogous to this version of naming and the plants should be treated as cultivars even if they are not named as such. The specific name is then a label and can be treated as such. The problem only arises when the system is micused, but as i have said earlier, this is open to abuse in any market situation.

The way we use plants is vastly different to how most would spread in the wild - grafting being perhaps the most extreme example, but that affects how we should look at the plants we cultivate differently to how we would study a field of them in the wild.

As to genetic variation being the final say in what is, or isn't, a species this needs to be very carefully looked at, as Bigtroutz basically said. A recently published piece paper described a new species of Discus (_Symphyosodon tarzoo_) from a genetic study, but said that _Symphyosodon discus _and _S.aequafasciatus _show NO detectable differences. (New Discus named Symphysodon tarzoo | Practical Fishkeeping magazine) This does not make them the same species. A single mutation (undetectable in most of these fingerprint studies as opposed to sequencing work) in a single gene COULD change an organism drastically (e.g. Sickle cell aneamia).

Sorry for this overlong rant - Merry Christmas everyone, i'm going back to the beer! (if you're interested in this kind of thing I hope Santa brings you the 'Selfish Gene' by Richard Dawkins - an excellent read!)


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## bigtroutz (Nov 17, 2006)

A good try, Ed. But some plant cultivars do have considerable variability and others are actually hybrids between species made viable thru polyploidy and this reflects the actual range of possibilities which are also found in 'natural' populations.

A good example is triticale, which is a polyploid hybrid cross between wheat and rye. The first man-induced hybrids date from the late 1800s. Much later, viable 'naturally' occuring triticale hydrids were found in Russia. I won't comment on the viability of calling wheat and rye separate species except to point out that calling them separate species given their 'natural' ability to interbreed is an excelllent example of how separating species is arbitrary. In this case, separating genera may be arbitrary as well, lol


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## Cavan Allen (Jul 22, 2004)

> Are humans somehow not natural ?


That's a tough question to answer, but we're definitely not the same as other 'natural' forces in terms of how we influence things.



> Are we not animals and members of the 'natural' world?


Of course.



> Hubris is thinking we are better/above it all somehow.


I know what that means, thanks.



> Varieties created by man are the same as varieties created by 'natural' processes because man is just another 'natural' process


No, they aren't and no, we aren't. Evolving into something slightly different over thousands of years is not the same as being created in a greenhouse. A scientifically described variety is different from what is described here:
International Union for the Protection of New Varieties of Plants - Wikipedia, the free encyclopedia

While it _can_ be proper to describe a new variety of developed plant, it isn't correct to denote something as _Hygrophila polysperma_ var. 'Sunburst' (not a real plant). Leave out the 'var' and it's OK.


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## ed seeley (Dec 1, 2006)

bigtroutz said:


> But some plant cultivars do have considerable variability and others are actually hybrids between species made viable thru polyploidy and this reflects the actual range of possibilities which are also found in 'natural' populations.
> 
> A good example is triticale, which is a polyploid hybrid cross between wheat and rye. The first man-induced hybrids date from the late 1800s. Much later, viable 'naturally' occuring triticale hydrids were found in Russia. I won't comment on the viability of calling wheat and rye separate species except to point out that calling them separate species given their 'natural' ability to interbreed is an excelllent example of how separating species is arbitrary. In this case, separating genera may be arbitrary as well, lol


None of those are Cultivars. They are cultivated plants but that is not the same. Equally no grain crop is propagated vegetatively so obviously there will be genetic variation. In the specialist horticultural world (certainly this side of the atlantic) the example you gave would, at best, be correctly called a seed strain and any offspring would have to be rigourously selected before they could be traded as the same cultivar as the parent plant. The Royal Horticultural Society judges that a plant cultivar should be propagated vegetatively to truely be regarded as the same. If they must be raised from seed they must be rigourously selected to maintain the qualities of the cultivar. A difference of 10% (though who would judge this?) is toted as an accepatble variation. As a plant producer even to offer plants with this much variation would be totally unacceptable as the plants would bear only a resemblance to the true form.

A Hybrid can be a cultivar in EXACTLY the same way that any other selected plant can be, and many, many are, including almost every rose grown in gardens. Purity of a 'species' is neither here nor there when considering any of this. However to be a cultivar this hybrid would be selected and propagated vegetatively so that, for example, EVERY Rosa 'Iceberg' grown would be identical, baring somatic mutation.

The essence is that a cultivar is a unique, isolated plant selected for some unique property(ies). Until it is discovered and held up as such by it's discoverer, it is no more than part of the variation present within every genetic population, whether natural or 'man-made'. Once it is isolated and named as a cultivar however, and it is ascribed that special status, it is a separate matter and does not represent the scope of genetic variation present in the original genetic population.

The example of triticale is akin to a mule (whether fertile or not), and no one would attempt to say that any horse/ass cross is the same as every other one. Such a cross between variable parents would obviously produce even more variable offspring. These, however could not be considered to be a cultivar. For that to happen someone, as i said above, would have to select a plant(s) and keep them isolated for some particular quality.

I agree that species, genera, even families and orders (especially when considering bacteria and single celled plants and fungi) are ALL arbitary judgements made by people. The only difference is how many people agree with what another person has decided. That is the only thing that makes any 'difference' more accepted.


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## bigtroutz (Nov 17, 2006)

Cavan Allen said:


> That's a tough question to answer, but we're definitely not the same as other 'natural' forces in terms of how we influence things.


THAT is hubris.

Humans are just another naturally evolved species on earth and just as unique as any other species. There is absolutely nothing that man does that does not have a 'natural' analogue.

Suggest something that makes man different from any other 'natural' influence and I will endeavor to provide the comparable non-human analogue.

Man has a long history of finding something in nature to emulate and claiming it as his invention, or inventing something and discovering that better analogues are already present in nature, often pre-existing for millions of years.

BTW, evolution of a new species can be quite rapid; experiments wirh house flies have demonstrated the necessary components required for species formation in roughly 25 generations (about one year). Just multiply 25 times the age at first breeding and you have a rough minimum estimate of the time required for a new species. For humans, 25 x 15 = 375 years. Of course, the conditions required for species formation must also be present, eg reproductive isolation of 'subspecies' in time and/or space. Although species formation may or may not take a long time, thousands of years are not *required*.

Ed, there is no requirement that a cultivar be a clone, although some are:

_Article 2.1 of the International Code of Nomenclature for Cultivated Plants states that a cultivar is the "primary category of cultivated plants whose nomenclature is governed by this Code." and defines a cultivar as "an assemblage of plants that has been selected for a particular attribute or combination of attributes, and that is clearly distinct, uniform and stable in its characteristics and that, when propagated by appropriate means, retains those characteristics" (Art. 2.2)._

Further:
_There is not necessarily a relationship between any cultivar and any particular genome. The ICNCP emphasizes that different cultivated plants may be accepted as different cultivars, even if they have the same genome, while cultivated plants with different genomes may be a single cultivar. In some cultivars, the human involvement was limited to making a selection among plants growing in the wild. Other cultivars are strictly artificial: the plants must be made anew every time, as in the case of an F1 hybrid between two plant lines. It is not required that a cultivar can reproduce itself. The "appropriate means of propagation" vary from cultivar to cultivar. This may range from propagation by seed which was the result of natural pollination to laboratory propagation. Many cultivars are clones propagated by cuttings, grafting, etc._

ex Cultivar - Wikipedia, the free encyclopedia

If the Royal Horticultural Society has a different definition of 'cultivar', more power to them. :sing:

Rye, Wheat and Triticale are all or contain culivars as subsets and the fact that Rye and Wheat hybridize into Triticale naturallly is a good example of how species and genus are set arbitrarily, as you agree.

If mules were fertile, they would be another good example of arbitrary species, but that is not required, There are many thousands of examples of species defined by some taxonomist that weren't actually unique species.

The point I was making is that setting species/cultivars/subspecies/etc is arbitrary and even genera, families, etc are arbitrary human constructs that attempt to define the functional genetics underlying individuals and populations with varying degrees of success.

We use the term cultivar to define a set of attributes in a plant species subpopulation which presumably have some utility to us. As long as we all understand that the distinctions here are arbitrary, we are good to go.

We certainly find these labels useful, perhaps more so than common names, since there is no scientific rigor (*such as it is*) associated with common names.

Another point I am making is that we should not take ourselves too seriously; the rules and actualities of binomial nomenclature are *useful fictions*, and subject to continual change. Think of them as working hypotheses, not as FACTS, at least given our present understanding of how nature works and the specifics of each case.


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## Cavan Allen (Jul 22, 2004)

> THAT is hubris.
> 
> Humans are just another naturally evolved species on earth and just as unique as any other species. There is absolutely nothing that man does that does not have a 'natural' analogue.


Uh, no. Humans have altered our planet in ways never before seen in, relatively speaking, a very short amount of time. To say that we are apart from nature and above it is hubris. To say that we haven't had an impact perhaps greater than any other species borders on the ridiculous. There's a big difference!

Do other species selectively breed other species to create new forms? No.

You may have the final word in our debate if you like, but after that let's try to keep this on topic.


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## BryceM (Nov 6, 2005)

What was Cavan's original topic anyway?

I can't remember, but it seems like it was a good one, if I'm remembering correctly. *** Unsubscribe ***


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## bigtroutz (Nov 17, 2006)

*The topic is the 'anatomy of a scientific name'.*



Cavan Allen said:


> Uh, no. Humans have altered our planet in ways never before seen in, relatively speaking, a very short amount of time. To say that we are apart from nature and above it is hubris. To say that we haven't had an impact perhaps greater than any other species borders of the ridiculous. There's a big difference!
> 
> Do other species selectively breed other species to create new forms? No.
> 
> You may have the final word in our debate if you like, but after that let's try to keep this on topic.


I am not looking for the final word. Rather, my aim is that readers of this thread understand that the anatomy of a scientific name, while useful, has certain limitations. Scientific names are more precise and global than common names as conventions, but they remain conventions/approximations/working hypotheses rather than 'truths' and should be considered in those terms.

As an example of a species selectively breeding other species to create new 'forms' there are leaf cutting ants of the group "Attini" 210 species found mostly in the neotropics of South America" which have domesticated/bred a fungus Attamyces bromatificus for 'farming'. In addition, they have domesticated and 'bred' a Streptomyces bacterium used to control unwanted 'weeds' in their fungal gardens.

ENHS Nature Trails May 99 Article 2
Fungus

While the above is an interesting example, almost all animals 'selectively breed' their food source by preferential consumption. As an example, the growth of plant thorns is enhanced by preferential feeding by herbivores.

Plants selectively breed their predators by raising the titres of certain systemic poisons until only the predators which specialize in feeding on that species CAN feed on that species and vice versa eg milkweed and monarch butterflies. In short, milkweed has selectively bred monarch butterflies, even though that may or may not have been their intention (lol). Scientist have not yet been able to get milkweeds to respond to these allegations of malfeasance.

Yersinia pestis bacteria selectively breed humans as in the case of the mass mortality of humans in the middle ages and the resulting rise of certain genotypes. Humans evolve too, you know.

Darwin Awards


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## Cavan Allen (Jul 22, 2004)

bigtroutz said:


> I am not looking for the final word. Rather, my aim is that readers of this thread understand that the anatomy of a scientific name, while useful, has certain limitations. Scientific names are more precise and global than common names as conventions, but they remain conventions/approximations/working hypotheses rather than 'truths' and should be considered in those terms.


I don't disagree with you there. Rather, my aim has been to illustrate the rules of nomenclature accurately even though they do, as you have pointed out, have limitations.

Yes, some animals do farm and maintain other species and some species are found only in association with others. The garibaldi damsel fish of the Pacific coast is another example (it removes unwanted algae species from its farming area). Has any of that resulted in the evolution of new species? Were any of them created intentionally?


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## bigtroutz (Nov 17, 2006)

Intention is a human construct; one of those second order logic derivatives that seem unique to humans. Most definitions that try to discern what is unique to humans settle on these kinds of concepts and I can't disagree with these viewpoints. However, intention is only a state of mind. Many species can and do create other species through the elegant dance in time we call co-evolution. The result is the same.

To answer your first question, yes, the fungus farmed by the ants is a unique species found only in ant colonies. Given the millions of species of life on earth, a fairly large number of these species will have been created by the actions of other species, for that is the nature of evolution. The monarch is an obligate predator of milkweed; no other plant will do. The result of the co-evolution of plant and predators are new species, often by both partners in the scheme.


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