Question about Naked Ladies

Fri, 21 Dec 2007 12:53:31 PST
Just a thought, but I think the term you are looking for is 
'intergression'.  It is often used when discussing reticulate evolution, 
which is the evolutionary theory that speciation is like a group of 
rivulets that flow in and out of each other over time, creating at any 
given moment in time that what we define as species.  Intergression is 
the scale of diversity between two disparate entities, such as certain 
life-forms that span the planet and show form diversity, in many papers 
this is refered to hybridization.  One could see the two ends of the 
spectrum intergressing across the genetic diversity of intermediates or 

I've noted that various 'schools' of science seem to use different 
vocabularies to define similar principles.  Sort of like the use of 
common names....hmmm.  Cline I remember from my school years, refering 
to a series of related entities and also fits the definition partially, 
while Rassenkreis, which literally translates to circle of races, ist 
mir neu (is new to me!). I would think this is the same thing as cline. 
I think most schools now use clade, the relation groups/units used for 

In the big picture all things are related and the result of continuous 
evolutionary flow.  That would be intergression in the reticulate 
sense.  Now, if we could just nail the evolution of the involved 
vocabulary!  I get the feeling the names have been altered, as the need 
to hone the definition has evolved, which means, depending on when a 
particular text was published, the vocabulary may need to be translated.

It this getting confusing?

Wishing you all a wonderful holiday season,

Jamie V.

J.E. Shields schrieb:
> Steve, Jim McK., Jane, and all,
> I also encountered the term Rassenkreis first in regard to Lepidoptera, but 
> specifically to the butterfly Junonia coenia, which also ranges from 
> Florida across the central USA to Mexico and Central America.  It its case, 
> I think there is at best very limited fertility between the Florida and the 
> Central American forms, but with the same continuous fertility between 
> neighboring populations.  Steve described the situation very well 
> indeed.  I'm pretty fluent in German, but I also had to check the spelling 
> before proceeding with my original posting.
> I thank Jim McK. for reassuring me that cline is also applicable.  "Cline" 
> might be more botanical, or it might be just a matter of years.  I 
> encountered "Rassenkreis" at least 40 years ago.  It could easily have 
> fallen by the wayside in that length of time, especially considering the 
> degree of Anglicization of science in the intervening years.
> Jane, I have not encountered "continuum" used in a biological sense 
> before.   This probably shows how narrow my biology reading has been over 
> the years.
> Whether Jim's Lilium greyii/canadense situation is a cline or a localized 
> intergradation between two young, mostly allopatric and closely related 
> species is perhaps debatable.  I certainly don't know the situation with 
> Lilium.
> Where you have two mutually interfertile species existing in sympatric 
> populations, if there is a barrier, they can be pretty stable.  Introducing 
> the human element may be all that is needed to overcome such a barrier to 
> interbreeding.  I can see where, over time, and intermediate population 
> could take over or it could be extinguished.  If the parent species include 
> individuals that are not fertile with members of the other species, they 
> might prosper as the hybrids decrease.
> Getting back to vernacular names, I'd say there are many things you simply 
> cannot discuss using vernacular names.  On the other hand, the day is not 
> far off when species, local populations, and individuals will be identified 
> and defined by their DNA.  It's just the direction things are going and 
> will continue to go, barring some Armageddon or other broad catastrophe.
> Best wishes,
> Jim Shields
> in central Indiana (USA)

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