21
   

Can humans be divided ito subspecies?

 
 
farmerman
 
  1  
Reply Sat 28 Jul, 2012 07:24 am
@iamsam82,
Quote:


Sorry, but you are wrong. Equus ferus caballus and Equus ferus przewalskii are separate subspecies
They are classed so, but so what? Im sure their genic compliments are barely divergent. Lotsa evolution )read "Stable variation") can occur with very little or NO genetic difference.

They present the rules of speciation, in that most divergence occurs at the margins of the species range.
Look at Mus musculus, there are over 120 subspecies in the US alone .
iamsam82
 
  0  
Reply Sat 28 Jul, 2012 07:36 am
@Setanta,
Setanta wrote...
Quote:
I haven't claimed that this is race hate

Quote:
Don't try to get on your high horse about maturity, your thesis is infantile, and so is your presentation


Quote:
King of Spaz Racists


An element of conflict there.

Please ignore Setanta. I am still keen to receive any mature answers from those who can supply them on the issue of how and why the human animal came to be exempt from what appears standard taxonomical practice.
iamsam82
 
  1  
Reply Sat 28 Jul, 2012 07:47 am
@farmerman,
Quote:
They are classed so, but so what?


So why are humans exempt from this system? I accept that, ultimately, our system of classifying animals is at best arbitrary - of course, there is too much infintessimal diversity around the edges of species for subspecies to mean anything outside of a human-centric context. But, if we have a system, it should be universal.

The myriad differences between Mus musculus have generated subspecies such as Mus musculus castaneus (which I presume comes from the Latin word for chestnut - taxonomy in terms of colour?), and Mus musculus gentilulus and countles others. Often, the differences are simply size, colour, ear length, etc. Humans arguably show similar types of variety yet they remain unrecognised in taxonomy. Why?
Strauss
 
  1  
Reply Sat 28 Jul, 2012 07:55 am
Iamsam82 wrote:
So why are humans exempt from this system?


Maybe because humans are the only species who can think.

Well, some of them..

0 Replies
 
farmerman
 
  2  
Reply Sat 28 Jul, 2012 07:55 am
@farmerman,
Mayr (2000)What Evolition IS opened the discussion that seems to be manifest in IAM's argument attempt. IAM, you are confusing a species "concept" with actuall species "taxa". When we have a population of organisms in an area and they all have a separate highly uniform trait, we call that "Speciation' based upon a concept of speciation. Howver, these variants (like Allegheny Cave Rats have a long tail and short fur, while the Allegheny Rat (variant of Novegicus)
doesnt have these same features.

Homo s florensis is an xample of how "Island dwarfism" may be in effect. (island dwafism is just one explanation of these fossil Hominims). Its a subspecies but its based upon fossil species concepts only. Genetics and cladistics play a much bigger part than merely ascribing a species name to organism fossils that are separated by time.

We arent really sure what a species is determined by. Weve given some definitions based upon "freely breeding populations isolated sexually from other of its genera" Pfffft. We alwways create more problems than we solve and the simple solution would be that species are mere place holders in time and space. We give them names because we must. BFD

PS Przewalski horses are more a product of their steppe diets and are very similar to how the Apache or Cheyenne Indians had taken the SPanish war horses and, in less than 200 years, turned them into big bellied grazers who responded to diets of sparse vegetation. These horses also began their own journey into a parallel "species" as the przewalskis.
farmerman
 
  1  
Reply Sat 28 Jul, 2012 07:58 am
@iamsam82,
Quote:
So why are humans exempt from this system? I accept that, ultimately, our system of classifying animals is at best arbitrary - of course, there is too much infintessimal diversity around the edges of species for subspecies to mean anything outside of a human-centric context. But, if we have a system, it should be universal.
Youve sort of answered yourself. WE CLASSIFY THINGS MORE BECAUSE THAT IS WHAT WE DO>
Do we really need to insert a Linnean classification unto our ownkind?

WHY?
0 Replies
 
iamsam82
 
  1  
Reply Sat 28 Jul, 2012 08:07 am
@farmerman,
You say species is defined as
Quote:
"freely breeding populations isolated sexually from other of its genera"


Thanks for this. How would subspecies be defined?

Also...

Quote:
Do we really need to insert a Linnean classification unto our ownkind?

WHY?


Because we do it for all other animals. Furthermore, greater investigation into and recognition of the differences between the possible subspecies of the human animal could yield real advances in medicine - I'm sure I've heard before that Africans are more susceptible to sickle cell anaemia. I bet there are other health differences between the proposed subspecies which are worthy of investigation, if only we acknowledged the acknowledgment of difference as something positive rather than instantly branding it racism, as some members of a2k are apt to do.
Further investigation of human subspecies might also give insight into and add detail to our understanding of human evolution and the way we anciently spread across the globe and chose to live.
Thomas
  Selected Answer
 
  6  
Reply Sat 28 Jul, 2012 08:18 am
@iamsam82,
iamsam82 wrote:
Please note, I do not intend to be racist at all. This is a legitimate question that has always puzzled me: Clear, visible, demonstrable differences within a species, but unrecognised in formal scientific classification. Why?

In a word: globalization.

Remember how biologists delimit species and subspecies: Two individuals belong to the same species if they can produce offspring and if this offspring is fertile. They belong to different subspecies of the same species if they wouldn't normally mate due to geographical separation.

By this standard, biologists from 1,000 years ago might have reasonably divided homo sapiens into geographically distinct subspecies. But they couldn't anymore. To be sure, humans from different continents still mate less frequently nowadays than humans from the same continent will. Nevertheless, they do mate and produce fertile offspring frequently.

Also notice that international migration has much weakened the correlation between geographical separation and the clear, visible differences you are talking about. For example, African-Americans and European-Americans look different, but are geographically close (and reproduce with each other often). By contrast, African-Americans and sub-Saharan Africans look similar, but they're geographically separate, reproducing rarely.

For both of these reasons, it makes no sense to divide humans into subspecies today. There is only one species.
farmerman
 
  2  
Reply Sat 28 Jul, 2012 08:46 am
@iamsam82,
Statistically , sickle cell anemia rides along with immunity from malaria. The slave trade to the new world has often been tied to the fact that early settlers who brought indentured servants from their own homelands saw that mpot of these died frommalaria. SO, whe it was discovered that Many AFricans had immunity to malaria (falciparum included0, then slavery became a way of life for the latitudes south of where the Anapholes didnt winter over. In New ENgland it was till a society of indentured servants who became greed men after a contractual obligation and (often_) some money changed hands.
In the area south of the MAson Dixon line , (The farthest N advance of falciparum malaria was about Richmond or DC at the most).

All those definitions and "tests" of subspeciation are just bullshit based upon homeranges of organisms. Species can diverge based upon geographic isolation until species are confidently assigned. EVEN so, there are often miscalls, like the red wolves of the AFar, or BArren ground Grizzlies, Kodiak Island Grizzlies, Alaskan Brown Grizzlies, and Mountain Grizzlies

I like Thomas take on the globalization of our species.
I suppose if you really need to insert humans within a mechanistic ( and quite artificial) Creationist classification ystem, I cant top you, its just that Id get a better feel of the actual "Species problem" and the concepts of phylogenetic species v geological species.

EO Wilson has a really good (And approachable) discussion of the species v subspeies v population controversy.
parados
 
  1  
Reply Sat 28 Jul, 2012 08:49 am
@iamsam82,
I think you don't get it because you are not trying to get it.

You have presented no evidence that your 2 partridges can breed and produce viable and fertile offspring.
iamsam82
 
  1  
Reply Sat 28 Jul, 2012 08:52 am
@farmerman,
Creationist?!! How so? I have no intention of appearing creationist. That's almost a worst insult to me than the ones Setanta was dishing out! Wink
iamsam82
 
  1  
Reply Sat 28 Jul, 2012 08:57 am
@parados,
I get it now. Thomas' answer is a good one. It acknowledges that at one time in history we could rightly have assigned subspecies to humans but that, because of the blurring of geographical boundaries nowadays, it is impossible to continue to do so.

I never said the partridges could. I asked can they not interbreed. In the case of Equus ferus przewalskii and Equus ferus caballus, however, interbreeding can happen.

Quote:
Przewalski’s horse can interbreed with the domestic horse and produce fertile offspring

http://en.wikipedia.org/wiki/Przewalski%27s_horse

So, granted, I have only one instance of subspecies being able to breed. I'm confident there are many more.
0 Replies
 
Pamela Rosa
 
  -2  
Reply Sat 28 Jul, 2012 08:58 am
Quote:
today forensic anthropologists can classify a person's race with an accuracy close to 100% based on only skeletal remains

http://en.wikipedia.org/wiki/Race_and_genetics
parados
 
  4  
Reply Sat 28 Jul, 2012 09:00 am
@Pamela Rosa,
Today, anyone can classify a person as a racist with 100% accuracy.

I guess that makes you an inferior race Pamela.
0 Replies
 
Setanta
 
  0  
Reply Sat 28 Jul, 2012 10:17 am
@iamsam82,
You got mature answers from me, but you wanted to argue them based on your puerile thesis.
0 Replies
 
Setanta
 
  1  
Reply Sat 28 Jul, 2012 10:40 am
@Thomas,
My initial response was much the same as yours, however, at the time i made it, i assumed the OP was calling for more detailed information, to i expatiated at length. Where i disagree with you is on the issue of sexual isolation. This is why i mentioned the Lemba of southern Africa, and the colonization of Madagascar by Australasians thousands of years ago. If the Australasians could reach Madagascar in numbers sufficient to colonize, they easily could have reached other parts of Asia and Africa. The Polynesians are descended from Australasians who travelled east rather than west.

When i mentioned the Solutrean hypothesis, i did not mention the Red Paint People hypothesis (which holds that people from North America were a part of a circumpolar culture, and that they visited western Europe thousands of years ago) nor the specifics of the alleged debunking of the Solutrean hypothesis based on genetic studies. That was because the post was getting too long as it stood. Two studies that i know of which were done within the last decade challenge the Solutrean hypothesis on the allegation that archaic European MtDNA is present in American aboriginals because it was present in the population of northeast Asia from which the aboriginal American population derived. Whether or not one cherishes the Solutrean hypothesis, such a claim does not "debunk" the proposition that this shows that there was not sexual isolation between the population of Europe and that of northeast Asia.

So i would dissent from your position by saying that any sexual isolation was a cultural artefact of the last millenium.
Walter Hinteler
 
  1  
Reply Sat 28 Jul, 2012 11:11 am
@Thomas,
Thomas wrote:
By this standard, biologists from 1,000 years ago might have reasonably divided homo sapiens into geographically distinct subspecies.
Actually, it was done by Linné in 1766: Homo sapiens with two species, homo diurnus (day man) and homo nocturnus (night man). The homo diurnus had four subspecies, according to the four continents known at that time ...
Thomas
 
  1  
Reply Sat 28 Jul, 2012 12:18 pm
@Setanta,
Setanta wrote:
So i would dissent from your position by saying that any sexual isolation was a cultural artefact of the last millenium.

Fair enough, but I don't think this distinction would make a difference to taxonomists.

In a section of The Ancestor's Tale, Richard Dawkins discusses speciation and some conceptual problems surrounding it. One of his examples involves two closely related insect species. They live in the same places and differ in only one trait: In courting females, the males of one species 'sing' a particular 'song'; those of the other, don't. When zoologists put 'non-singing' males into a terrarium with 'song-loving' females, nothing happens: 'Song-loving' females reject males who can't 'sing'. But when the zoologists play the missing 'song' from tape, the two mate and produce fertile offspring with no problem.

Using just a hint of poetic license, then, you could reasonably dismiss the sexual isolation of these species as a mere cultural artifact. Nevertheless, biologists agree in treating them as separate species. The core test for taxonomists seems to be procreation in the wild; they don't appear to distinguish much between reasons for not procreating.
Setanta
 
  1  
Reply Sat 28 Jul, 2012 12:32 pm
@Thomas,
However, i have been referring to examples in which there is DNA evidence that sexual isolation was not present. The American aboriginals have archaic European MtDNA. That a couple of studies in the last decade have claimed that the Solutrean hypothesis is debunked because the DNA is present in the source population doesn't alter that, obviously, there was reproductive contact between mesolithic or upper paeleolithic Europeans and the population of northeast Asia at some point 12,000 ybp or earlier.

So my point is about sexual isolation before the artificial sexual isolation of culture intervenes. Even acknowledging your point about the insects, the last 1000 years is not long enough for speciation to have taken place. What is more crucially important is that more and more evidence accumulates that sexual isolation was not necessarily common thousands of years ago, in the time pweriod in which speciation would have had to have taken place. So, for example, Australian aboriginals were (at least mostly) isolated for 40,000 years before 1788 (although some anthropologists how dispute this), yet they are reproductively modern humans.
0 Replies
 
farmerman
 
  2  
Reply Sat 28 Jul, 2012 12:33 pm
@iamsam82,
Quote:
Creationist?!! How so? I have no intention of appearing creationist. That's almost a worst insult to me than the ones Setanta was dishing out!
The Linnean system is based upon a Creationist worldview. It was a system of its time so I wouldnt worry about where you stand. Its been in constant (Albeit more grudging ) use since Karl von Linneaus (his lAtinized monicker) proposed it. In his foreword he had proposed the system based upon how separate , athough quite similar< animals and plants, reproduce "After their kinds"

We use the Linnean system because its easy to subdivide organisms by their similrities and its based upon the 7 (now 8) fold subdivisions in which an organism resides. New genetic studies have shown that, instead of similarities of the Linneans, a newer , IMHO, correct system is basd upon genetics and many times similarites of the phenotype arent even close. Like the elephant and the hyrax, or the pre equu and the whales and pinninpeds
 

Related Topics

New Propulsion, the "EM Drive" - Question by TomTomBinks
The Science Thread - Discussion by Wilso
Why do people deny evolution? - Question by JimmyJ
Are we alone in the universe? - Discussion by Jpsy
Fake Science Journals - Discussion by rosborne979
Controvertial "Proof" of Multiverse! - Discussion by littlek
 
Copyright © 2021 MadLab, LLC :: Terms of Service :: Privacy Policy :: Page generated in 0.04 seconds on 10/16/2021 at 12:47:32