[ECOLOG-L] Ecology Competition as a concept and a phenomenon Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-28 Thread Wayne Tyson

Ecolog, Joshua, and David:

Competition is a cultural tag we hang on observed phenomena to which we 
can relate. Suppression is another one, and I have been known to use both. 
I still use suppression, but I have at last eschewed the use of, nay, the 
very thought of, competition.


Organisms are not at war with each other, they're just ebbing and flowing 
with the tides and winds, the slings and arrows of outrageous fortune as 
it were, jes' a lookin' fer a home, as the old boll-weevil song goes.


Methinks too many doth proclaim too much.

WT


- Original Message - 
From: David Duffy ddu...@hawaii.edu

To: ECOLOG-L@LISTSERV.UMD.EDU
Sent: Thursday, April 26, 2012 7:02 PM
Subject: Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or 
progression?




I feel that competition without a doubt is beneficial, perhaps necessary,
for an ecosystem to continue progressing towards a more complex and
stronger state.

However, my thought was that ecosystems are cyclical and 
self-regulating.


native (albeit weaker) species

I am not sure there is much evidence that ecosystems progress towards a
more complex and stronger state, even if we do not ask whether if
competition is beneficial or even a dominant force. Nor is there
evidence, with a few exceptions, that ecosystems are cyclical, much less
self regulating and then only if you carefully pick your scale.  One might
argue that much of ecological theory has been a repeat of the
Gleason-Clements debate, an argument between those who seem life dominated
by random events and those who see homeostasis and orthogenesis, perhaps
with a pinch of Nietzchian der Wille zur Macht thrown in.  This colors
current discussions of invasive species, probably far more than any
confusion over what invasive means.

David Duffy


On Thu, Apr 26, 2012 at 3:11 PM, Joshua Wilson
joshua.m.wils...@gmail.comwrote:


Good evening,

First off, thank you for the wealth of responses, a number of them helped
to solidify and clarify ideas on this issue.  I had been waiting for all
responses before I replied with a sort of meta-analysis of what came in.
 The replies were more numerous and substantial than I had anticipated, 
so

thank you again.

Now to clarify.  When I mentioned progression, my idea was that an 
invasive

species encourages competition, and in some cases extreme and
insurmountable competition.  I feel that competition without a doubt is
beneficial, perhaps necessary, for an ecosystem to continue progressing
towards a more complex and stronger state.

The complication arises when an introduced species or a native species 
that
becomes dominant are able to outcompete the other species in the 
ecosystem

to the point of the only species able to compete is itself.  In these
instances, there are various stances to take, some of which I've heard
through responses (again, thank you).  From the complete control and
restoration of native (albeit weaker) species, to letting nature run its
course. However, my thought was that ecosystems are cyclical and
self-regulating.  And as Wayne Tyson said, we are interrupting and
influencing this.  This leads to many more questions.  With what I've
learned so far through this posting, exhaustive studies would be needed 
to

determine the best course of action for a particular system or species.
 Even then, the needed actions to benefit one species might directly
contradict the needs of another.  There are multitudes of variables that
need to go into project planning, not the least of which is *us, *and we
cannot foresee the ripple effects of what we'll do.

On the other hand, certain invasive species have led to unforeseen
benefits.  I will mention *Tamarix* *spp.* in this instance.  But even 
with

the detriments and benefits, there is a threshold to each.  Likewise,
invasive species seem to provide species-specific detriments (or 
benefits).

 One can call it a culling of the weak species and the establishment of
stronger (which in my mind is necessary for progression), or unfair
competition, invasive species are not by nature detrimental.

I've rambled far more than I expected to, and not as cohesive as some 
might

like.  My knowledge and experiences are limited, hence my original
question, but I've a sincere interest in these ideas.  Again, I would
welcome any thoughts, ideas, questions, or comments.  Thank you all 
ECOLOG,

this is a great resource for undergrads, post-docs, and interested
individuals alike.  Keep it up.

Have a good night all,

Josh

On Thu, Apr 26, 2012 at 4:44 PM, Wayne Tyson landr...@cox.net wrote:

 Ecolog,

 I am dismayed that there has been so little response to Huang's
questions.
 Perhaps I am wrong in that assumption and they have been. But it seems 
 to
 me that the questions should be addressed and some conclusions 
 concluded,

 even if they are two-headed.

 I suggest that everyone read the article to which Huang supplied a 
 link.

 It is not long, nor is it complicated. I suspect

Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-28 Thread Wayne Tyson

Ecolog and Joshua:

Being cocksure about anything is a bad habit for anybody to cultivate, is 
damnfoolish for ecologists, and verboten for scientists. Egocentrism and 
science do not mix, but lo, the plethora of contradictions of this statement 
that exist in the really, really unreal world of civilization. Had we been 
possessed of better angels, we might have rejected the mess of culture 
(cultivation--enslavement of plants and animals) at the outset and would 
still be residing in Eden, laughing and loving and standing in awe of this 
awesome Earth and Universe, calling our place in it, and seeing it as, good.


We might be extinct. Maybe we are, in ecological terms. For the most part we 
have become wholly dependent upon the products of culture--and these pixels 
are proof of that, at least in this instance? Irony anyone?


With respect to plants (more irony, at least in ambiguity), I am astonished, 
nay, blown away, that the concept of natives invading a place where they 
evolved, exists at all. I must be missing something, but I'll be damned if I 
can guess what it is.


WT


- Original Message - 
From: Joshua Wilson joshua.m.wils...@gmail.com

To: ECOLOG-L@LISTSERV.UMD.EDU
Sent: Thursday, April 26, 2012 6:11 PM
Subject: Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or 
progression?




Good evening,

First off, thank you for the wealth of responses, a number of them helped
to solidify and clarify ideas on this issue.  I had been waiting for all
responses before I replied with a sort of meta-analysis of what came in.
The replies were more numerous and substantial than I had anticipated, so
thank you again.

Now to clarify.  When I mentioned progression, my idea was that an 
invasive

species encourages competition, and in some cases extreme and
insurmountable competition.  I feel that competition without a doubt is
beneficial, perhaps necessary, for an ecosystem to continue progressing
towards a more complex and stronger state.

The complication arises when an introduced species or a native species 
that

becomes dominant are able to outcompete the other species in the ecosystem
to the point of the only species able to compete is itself.  In these
instances, there are various stances to take, some of which I've heard
through responses (again, thank you).  From the complete control and
restoration of native (albeit weaker) species, to letting nature run its
course. However, my thought was that ecosystems are cyclical and
self-regulating.  And as Wayne Tyson said, we are interrupting and
influencing this.  This leads to many more questions.  With what I've
learned so far through this posting, exhaustive studies would be needed to
determine the best course of action for a particular system or species.
Even then, the needed actions to benefit one species might directly
contradict the needs of another.  There are multitudes of variables that
need to go into project planning, not the least of which is *us, *and we
cannot foresee the ripple effects of what we'll do.

On the other hand, certain invasive species have led to unforeseen
benefits.  I will mention *Tamarix* *spp.* in this instance.  But even 
with

the detriments and benefits, there is a threshold to each.  Likewise,
invasive species seem to provide species-specific detriments (or 
benefits).

One can call it a culling of the weak species and the establishment of
stronger (which in my mind is necessary for progression), or unfair
competition, invasive species are not by nature detrimental.

I've rambled far more than I expected to, and not as cohesive as some 
might

like.  My knowledge and experiences are limited, hence my original
question, but I've a sincere interest in these ideas.  Again, I would
welcome any thoughts, ideas, questions, or comments.  Thank you all 
ECOLOG,

this is a great resource for undergrads, post-docs, and interested
individuals alike.  Keep it up.

Have a good night all,

Josh

On Thu, Apr 26, 2012 at 4:44 PM, Wayne Tyson landr...@cox.net wrote:


Ecolog,

I am dismayed that there has been so little response to Huang's 
questions.

Perhaps I am wrong in that assumption and they have been. But it seems to
me that the questions should be addressed and some conclusions concluded,
even if they are two-headed.

I suggest that everyone read the article to which Huang supplied a link.
It is not long, nor is it complicated. I suspect that there may be a
fundamental flaw in the article's premise, but I will leave that judgment
up to my betters . . .

Coincidentally, Joshua Wilson's original post (Invasion or progression?)
did not define progression, nor has anyone else, and Wilson has not
responded to my request for a definition. I think it is essential that it
be defined before his question can be answered. If Josh was just joshing
us, or he is incapacitated, I may have to lower his grade from an A+ to,
say, a C for mediocrity, due to his unresponsiveness. Are you there, 
Josh?


I will await

Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-28 Thread Eric North
I cant help but find irony in that in one breath (read: keystroke) we cannot 
agree on a definition of an invasive species invasion or the like, or, 
seemingly, even if there is such a thing as invasive species when put into the 
context of evolutionary time. At the same time, there is the opinion at least 
being discussed here, that there are species that are so successful as to be 
eradicable.  
 
eric

Eric North 
All Things Wild Consulting
P.O. Box 254
Cable, WI 54821
928.607.3098

 

 Date: Fri, 27 Apr 2012 22:03:25 -0700
 From: landr...@cox.net
 Subject: Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or 
 progression?
 To: ECOLOG-L@LISTSERV.UMD.EDU
 
 Ecolog and Joshua:
 
 Being cocksure about anything is a bad habit for anybody to cultivate, is 
 damnfoolish for ecologists, and verboten for scientists. Egocentrism and 
 science do not mix, but lo, the plethora of contradictions of this statement 
 that exist in the really, really unreal world of civilization. Had we been 
 possessed of better angels, we might have rejected the mess of culture 
 (cultivation--enslavement of plants and animals) at the outset and would 
 still be residing in Eden, laughing and loving and standing in awe of this 
 awesome Earth and Universe, calling our place in it, and seeing it as, good.
 
 We might be extinct. Maybe we are, in ecological terms. For the most part we 
 have become wholly dependent upon the products of culture--and these pixels 
 are proof of that, at least in this instance? Irony anyone?
 
 With respect to plants (more irony, at least in ambiguity), I am astonished, 
 nay, blown away, that the concept of natives invading a place where they 
 evolved, exists at all. I must be missing something, but I'll be damned if I 
 can guess what it is.
 
 WT
 
 
 - Original Message - 
 From: Joshua Wilson joshua.m.wils...@gmail.com
 To: ECOLOG-L@LISTSERV.UMD.EDU
 Sent: Thursday, April 26, 2012 6:11 PM
 Subject: Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or 
 progression?
 
 
  Good evening,
 
  First off, thank you for the wealth of responses, a number of them helped
  to solidify and clarify ideas on this issue. I had been waiting for all
  responses before I replied with a sort of meta-analysis of what came in.
  The replies were more numerous and substantial than I had anticipated, so
  thank you again.
 
  Now to clarify. When I mentioned progression, my idea was that an 
  invasive
  species encourages competition, and in some cases extreme and
  insurmountable competition. I feel that competition without a doubt is
  beneficial, perhaps necessary, for an ecosystem to continue progressing
  towards a more complex and stronger state.
 
  The complication arises when an introduced species or a native species 
  that
  becomes dominant are able to outcompete the other species in the ecosystem
  to the point of the only species able to compete is itself. In these
  instances, there are various stances to take, some of which I've heard
  through responses (again, thank you). From the complete control and
  restoration of native (albeit weaker) species, to letting nature run its
  course. However, my thought was that ecosystems are cyclical and
  self-regulating. And as Wayne Tyson said, we are interrupting and
  influencing this. This leads to many more questions. With what I've
  learned so far through this posting, exhaustive studies would be needed to
  determine the best course of action for a particular system or species.
  Even then, the needed actions to benefit one species might directly
  contradict the needs of another. There are multitudes of variables that
  need to go into project planning, not the least of which is *us, *and we
  cannot foresee the ripple effects of what we'll do.
 
  On the other hand, certain invasive species have led to unforeseen
  benefits. I will mention *Tamarix* *spp.* in this instance. But even 
  with
  the detriments and benefits, there is a threshold to each. Likewise,
  invasive species seem to provide species-specific detriments (or 
  benefits).
  One can call it a culling of the weak species and the establishment of
  stronger (which in my mind is necessary for progression), or unfair
  competition, invasive species are not by nature detrimental.
 
  I've rambled far more than I expected to, and not as cohesive as some 
  might
  like. My knowledge and experiences are limited, hence my original
  question, but I've a sincere interest in these ideas. Again, I would
  welcome any thoughts, ideas, questions, or comments. Thank you all 
  ECOLOG,
  this is a great resource for undergrads, post-docs, and interested
  individuals alike. Keep it up.
 
  Have a good night all,
 
  Josh
 
  On Thu, Apr 26, 2012 at 4:44 PM, Wayne Tyson landr...@cox.net wrote:
 
  Ecolog,
 
  I am dismayed that there has been so little response to Huang's 
  questions.
  Perhaps I am wrong in that assumption and they have been. But it seems

Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-28 Thread ryan unks
Dear Ling, WT, and Ecolog,

I think the term invasive implies that whatever is now dominating a system
came from some ambiguously demarcated outside due to human intervention.
The term is largely framed by our conception of history, and so we are
inconsistent about where we draw this line for outside.  From my
experience, most biologists use the term invasive in reference to a
dominant organism which is from outside an area it could not have dispersed
into without human assistance.  For example, most do not consider species
to be invasive when disturbance regimes or other processes have been
altered by humans from past conditions (this past can be equally
ambiguous in discussions) and allow for their dominance of local areas
where they could have dispersed into but probably didn't occur. I believe
it is for this reason I have never heard a biologist say a raccoon is
invasive in North America abefore this discussion. There may be examples
which contradict this definition that I have been using though, and I would
appreciate the correction and also would very much so appreciate if anyone
has a citation for a better definition in use if I am off on this.

So, to get around to addressing Ling and WT's questions, if we are
consistent with the underlying ideas of what is outside and what is inside
are used in our definition, native implies inside and invasive implies
outside, both to some predetermined space, and so I would say that the
answers to Ling's questions are:

1. (when) can an invasive become native?

no (or, never)

2. can an invasive become native?

no.

I think the words are actually logically exclusive of the other no matter
where we draw the line, it is where we draw that line that is contentious,
and essentially we would have to switch our conception (whatever that may
be) for an invasive to become native.


Best,
Ryan Unks

On Sat, Apr 28, 2012 at 11:44 AM, Eric North xcs...@hotmail.com wrote:

 I cant help but find irony in that in one breath (read: keystroke) we
 cannot agree on a definition of an invasive species invasion or the
 like, or, seemingly, even if there is such a thing as invasive species when
 put into the context of evolutionary time. At the same time, there is the
 opinion at least being discussed here, that there are species that are so
 successful as to be eradicable.

 eric

 Eric North
 All Things Wild Consulting
 P.O. Box 254
 Cable, WI 54821
 928.607.3098



  Date: Fri, 27 Apr 2012 22:03:25 -0700
  From: landr...@cox.net
  Subject: Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L]
 Invasion, or progression?
  To: ECOLOG-L@LISTSERV.UMD.EDU
 
  Ecolog and Joshua:
 
  Being cocksure about anything is a bad habit for anybody to cultivate, is
  damnfoolish for ecologists, and verboten for scientists. Egocentrism and
  science do not mix, but lo, the plethora of contradictions of this
 statement
  that exist in the really, really unreal world of civilization. Had we
 been
  possessed of better angels, we might have rejected the mess of culture
  (cultivation--enslavement of plants and animals) at the outset and would
  still be residing in Eden, laughing and loving and standing in awe of
 this
  awesome Earth and Universe, calling our place in it, and seeing it as,
 good.
 
  We might be extinct. Maybe we are, in ecological terms. For the most
 part we
  have become wholly dependent upon the products of culture--and these
 pixels
  are proof of that, at least in this instance? Irony anyone?
 
  With respect to plants (more irony, at least in ambiguity), I am
 astonished,
  nay, blown away, that the concept of natives invading a place where
 they
  evolved, exists at all. I must be missing something, but I'll be damned
 if I
  can guess what it is.
 
  WT
 
 
  - Original Message -
  From: Joshua Wilson joshua.m.wils...@gmail.com
  To: ECOLOG-L@LISTSERV.UMD.EDU
  Sent: Thursday, April 26, 2012 6:11 PM
  Subject: Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L]
 Invasion, or
  progression?
 
 
   Good evening,
  
   First off, thank you for the wealth of responses, a number of them
 helped
   to solidify and clarify ideas on this issue. I had been waiting for all
   responses before I replied with a sort of meta-analysis of what came
 in.
   The replies were more numerous and substantial than I had anticipated,
 so
   thank you again.
  
   Now to clarify. When I mentioned progression, my idea was that an
   invasive
   species encourages competition, and in some cases extreme and
   insurmountable competition. I feel that competition without a doubt is
   beneficial, perhaps necessary, for an ecosystem to continue progressing
   towards a more complex and stronger state.
  
   The complication arises when an introduced species or a native species
   that
   becomes dominant are able to outcompete the other species in the
 ecosystem
   to the point of the only species able to compete is itself. In these
   instances, there are various stances to take, some

Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-27 Thread Chris Buddenhagen
That would be most of them, if by eradicate you mean to remove all
reproducing individuals from  a defined region such that all individuals
are put at risk, and reinvasion or recovery is unlikely. The implication
being that after an eradication no further management investment is needed,
since the targeted invasive species is eradicated.

By the time most invasive plant problems are detected or recognized they
are uneradicable with normally available resources.

Some notable exceptions exist and many eradications have been successful
under the right conditions

Chris Buddenhagen
On Apr 26, 2012 11:11 PM, Martin Meiss mme...@gmail.com wrote:

 How about if we consider that invaders have become native when all efforts
 to eradicate them are futile?

 Martin M. Meiss


 2012/4/26 David Duffy ddu...@hawaii.edu

  I feel that competition without a doubt is beneficial, perhaps
 necessary,
  for an ecosystem to continue progressing towards a more complex and
  stronger state.
 
  However, my thought was that ecosystems are cyclical and
 self-regulating.
 
  native (albeit weaker) species
 
  I am not sure there is much evidence that ecosystems progress towards a
  more complex and stronger state, even if we do not ask whether if
  competition is beneficial or even a dominant force. Nor is there
  evidence, with a few exceptions, that ecosystems are cyclical, much less
  self regulating and then only if you carefully pick your scale.  One
 might
  argue that much of ecological theory has been a repeat of the
  Gleason-Clements debate, an argument between those who seem life
 dominated
  by random events and those who see homeostasis and orthogenesis, perhaps
  with a pinch of Nietzchian der Wille zur Macht thrown in.  This colors
  current discussions of invasive species, probably far more than any
  confusion over what invasive means.
 
  David Duffy
 
 
  On Thu, Apr 26, 2012 at 3:11 PM, Joshua Wilson
  joshua.m.wils...@gmail.comwrote:
 
   Good evening,
  
   First off, thank you for the wealth of responses, a number of them
 helped
   to solidify and clarify ideas on this issue.  I had been waiting for
 all
   responses before I replied with a sort of meta-analysis of what came
 in.
The replies were more numerous and substantial than I had anticipated,
  so
   thank you again.
  
   Now to clarify.  When I mentioned progression, my idea was that an
  invasive
   species encourages competition, and in some cases extreme and
   insurmountable competition.  I feel that competition without a doubt is
   beneficial, perhaps necessary, for an ecosystem to continue progressing
   towards a more complex and stronger state.
  
   The complication arises when an introduced species or a native species
  that
   becomes dominant are able to outcompete the other species in the
  ecosystem
   to the point of the only species able to compete is itself.  In these
   instances, there are various stances to take, some of which I've heard
   through responses (again, thank you).  From the complete control and
   restoration of native (albeit weaker) species, to letting nature run
 its
   course. However, my thought was that ecosystems are cyclical and
   self-regulating.  And as Wayne Tyson said, we are interrupting and
   influencing this.  This leads to many more questions.  With what I've
   learned so far through this posting, exhaustive studies would be needed
  to
   determine the best course of action for a particular system or species.
Even then, the needed actions to benefit one species might directly
   contradict the needs of another.  There are multitudes of variables
 that
   need to go into project planning, not the least of which is *us, *and
 we
   cannot foresee the ripple effects of what we'll do.
  
   On the other hand, certain invasive species have led to unforeseen
   benefits.  I will mention *Tamarix* *spp.* in this instance.  But even
  with
   the detriments and benefits, there is a threshold to each.  Likewise,
   invasive species seem to provide species-specific detriments (or
  benefits).
One can call it a culling of the weak species and the establishment of
   stronger (which in my mind is necessary for progression), or unfair
   competition, invasive species are not by nature detrimental.
  
   I've rambled far more than I expected to, and not as cohesive as some
  might
   like.  My knowledge and experiences are limited, hence my original
   question, but I've a sincere interest in these ideas.  Again, I would
   welcome any thoughts, ideas, questions, or comments.  Thank you all
  ECOLOG,
   this is a great resource for undergrads, post-docs, and interested
   individuals alike.  Keep it up.
  
   Have a good night all,
  
   Josh
  
   On Thu, Apr 26, 2012 at 4:44 PM, Wayne Tyson landr...@cox.net wrote:
  
Ecolog,
   
I am dismayed that there has been so little response to Huang's
   questions.
Perhaps I am wrong in that assumption and they have been. But it
 seems
  

[ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-26 Thread Wayne Tyson

Ecolog,

I am dismayed that there has been so little response to Huang's questions. 
Perhaps I am wrong in that assumption and they have been. But it seems to me 
that the questions should be addressed and some conclusions concluded, even 
if they are two-headed.


I suggest that everyone read the article to which Huang supplied a link. It 
is not long, nor is it complicated. I suspect that there may be a 
fundamental flaw in the article's premise, but I will leave that judgment up 
to my betters . . .


Coincidentally, Joshua Wilson's original post (Invasion or progression?) did 
not define progression, nor has anyone else, and Wilson has not responded 
to my request for a definition. I think it is essential that it be defined 
before his question can be answered. If Josh was just joshing us, or he is 
incapacitated, I may have to lower his grade from an A+ to, say, a C for 
mediocrity, due to his unresponsiveness. Are you there, Josh?


I will await the responses from others on the questions by Huang:

1. (When) do invasives become native?

2. Can natives become invasive?

I hope that greater responsiveness will encourage Huang, the chemist, to 
continue to take his cross-fertilization attempt seriously and not to give 
up on ecologists.


WT


- Original Message - 
From: ling huang ling.hu...@prodigy.net

To: ECOLOG-L@LISTSERV.UMD.EDU
Sent: Sunday, April 22, 2012 6:37 PM
Subject: Re: [ECOLOG-L] Invasion, or progression?


Hi

I am a chemist and not an ecologist but I'm very interested in this thread 
since I enjoy the wetlands area close to Sacramento near the Davis Yolo 
Causeway. I wondered and am interested in this invasive or progression type 
question. I saw that there was a species called Purple Loosestrife (Lythrum 
salicaria) that was introduced in the 1800s (?) and is a wetland flower that 
has invaded wetlands. I suppose my question is how far do we go back to 
determine if a species is invasive. Is there a time or case when an invasive 
becomes a native? I did see this interesting online article where the 
question asked was Can native species become invasive?


http://ipmsouth.com/2010/11/23/can-native-species-become-invasive/

Thanks. Ling

Ling Huang
Sacramento City College


--- On Sun, 4/22/12, Amanda Newsom ajnew...@ucdavis.edu wrote:

From: Amanda Newsom ajnew...@ucdavis.edu
Subject: Re: [ECOLOG-L] Invasion, or progression?
To: ECOLOG-L@LISTSERV.UMD.EDU
Date: Sunday, April 22, 2012, 3:40 PM

Very intelligent members of the public have asked me this question when
they approach me in the field and I have some time to chat. It's a great
question, because invasions biology is attacked politically on this front,
so it's one to which professionals really must craft a coherent response in
friendly conversation.

Another point to consider is the evolutionary history of native vs.
introduced (non-native) species in any particular system. One of the
reasons non-natives are of concern is that they do not share evolutionary
history with the native community, and this contributes to the
unpredictable biodiversity loss cited by other comments presented here.
This can also be discussed in light of the homogenization of life on
earth, because there are many species favored, facilitated, or directly
cultivated by humans that are now distributed worldwide. Some of these
species threaten regional biodiversity (Check out the book Ecological
Imperialism for a really interesting perspective on colonialism as an
ecological process via introduction of new dominant species). There's a
lot coming out now on evolution and invasive species as well that is, at
least in part, reasonably accessible to a general audience or the academic
in ecology/evolution who is wanting to step into invasion biology.

Related to this (somewhat tangentially) is that the buildup of introduced
and invasive species in systems like San Francisco Bay has also increased
the number and complexity of biological interactions, both
introduced-introduced and introduced-native. Increasing professional
interest in introduced-introduced interactions hasn't yet yielded a whole
lot of generalized hypotheses, but it has opened new windows to how complex
this issue is biologically and how best to protect species of interest as
well as local biodiversity.

That was a far longer and more convoluted comment than I originally
intended! Hopefully, Joshua, some of that is useful perspective. Thanks
for posing the question to ECOLOG! It can be intimidating to put something
like this out there as an undergrad, and I'm glad you took the initiative.
It comes up a lot, as you can see, and ECOLOG is a great forum for this
discussion.
A.

On Sun, Apr 22, 2012 at 9:19 AM, Ruhl, Nathan nr343...@ohio.edu wrote:


I posed a very similar question to a group of graduate students and
professors during a theoretical ecology seminar a few years ago. The
central premise was that humans, by virtue of our innate-desire/ability to
alter our surroundings, have caused 

Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-26 Thread O'Brien, Erin
I think that the lack of a response is because there is no clear established 
rule about either but I suspect that folks have replied to Huang off list. 
Without academic references to back it up (I'm busy grading at the end of the 
semester) I will give two short answers based on what I have always been taught 
and used myself. 

1. Invasive species are generally considered native when there are endemics 
that specialize on the invasive species. An example would be Larrea tridentata 
which is a relative newcomer to North America, having hitched a ride on 
migrating birds from S. America in the last 20,000-30,000 years and then 
rapidly spread throughout its current range.
2. Natives can be considered noxious (http://plants.usda.gov/java/noxiousDriver 
) but the term invasive is generally not applied to natives. You have probably 
heard the term noxious weed before. This label is used regardless of the recent 
origin of the species. On a government policy level, the label invasive is 
restricted to non-natives (http://www.invasivespeciesinfo.gov/whatis.shtml ).

-Erin

Erin E. O'Brien, Ph.D.

Department of Biological Sciences
Dixie State College of Utah
225 South 700 East
St. George, UT 84770

Phone: (435) 652-7761
Fax: (435) 656-4002
Email: obr...@dixie.edu


-Original Message-
From: Ecological Society of America: grants, jobs, news 
[mailto:ECOLOG-L@LISTSERV.UMD.EDU] On Behalf Of Wayne Tyson

I will await the responses from others on the questions by Huang:

1. (When) do invasives become native?

2. Can natives become invasive?


Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-26 Thread Joshua Wilson
Good evening,

First off, thank you for the wealth of responses, a number of them helped
to solidify and clarify ideas on this issue.  I had been waiting for all
responses before I replied with a sort of meta-analysis of what came in.
 The replies were more numerous and substantial than I had anticipated, so
thank you again.

Now to clarify.  When I mentioned progression, my idea was that an invasive
species encourages competition, and in some cases extreme and
insurmountable competition.  I feel that competition without a doubt is
beneficial, perhaps necessary, for an ecosystem to continue progressing
towards a more complex and stronger state.

The complication arises when an introduced species or a native species that
becomes dominant are able to outcompete the other species in the ecosystem
to the point of the only species able to compete is itself.  In these
instances, there are various stances to take, some of which I've heard
through responses (again, thank you).  From the complete control and
restoration of native (albeit weaker) species, to letting nature run its
course. However, my thought was that ecosystems are cyclical and
self-regulating.  And as Wayne Tyson said, we are interrupting and
influencing this.  This leads to many more questions.  With what I've
learned so far through this posting, exhaustive studies would be needed to
determine the best course of action for a particular system or species.
 Even then, the needed actions to benefit one species might directly
contradict the needs of another.  There are multitudes of variables that
need to go into project planning, not the least of which is *us, *and we
cannot foresee the ripple effects of what we'll do.

On the other hand, certain invasive species have led to unforeseen
benefits.  I will mention *Tamarix* *spp.* in this instance.  But even with
the detriments and benefits, there is a threshold to each.  Likewise,
invasive species seem to provide species-specific detriments (or benefits).
 One can call it a culling of the weak species and the establishment of
stronger (which in my mind is necessary for progression), or unfair
competition, invasive species are not by nature detrimental.

I've rambled far more than I expected to, and not as cohesive as some might
like.  My knowledge and experiences are limited, hence my original
question, but I've a sincere interest in these ideas.  Again, I would
welcome any thoughts, ideas, questions, or comments.  Thank you all ECOLOG,
this is a great resource for undergrads, post-docs, and interested
individuals alike.  Keep it up.

Have a good night all,

Josh

On Thu, Apr 26, 2012 at 4:44 PM, Wayne Tyson landr...@cox.net wrote:

 Ecolog,

 I am dismayed that there has been so little response to Huang's questions.
 Perhaps I am wrong in that assumption and they have been. But it seems to
 me that the questions should be addressed and some conclusions concluded,
 even if they are two-headed.

 I suggest that everyone read the article to which Huang supplied a link.
 It is not long, nor is it complicated. I suspect that there may be a
 fundamental flaw in the article's premise, but I will leave that judgment
 up to my betters . . .

 Coincidentally, Joshua Wilson's original post (Invasion or progression?)
 did not define progression, nor has anyone else, and Wilson has not
 responded to my request for a definition. I think it is essential that it
 be defined before his question can be answered. If Josh was just joshing
 us, or he is incapacitated, I may have to lower his grade from an A+ to,
 say, a C for mediocrity, due to his unresponsiveness. Are you there, Josh?

 I will await the responses from others on the questions by Huang:

 1. (When) do invasives become native?

 2. Can natives become invasive?

 I hope that greater responsiveness will encourage Huang, the chemist, to
 continue to take his cross-fertilization attempt seriously and not to give
 up on ecologists.

 WT


 - Original Message - From: ling huang ling.hu...@prodigy.net
 To: ECOLOG-L@LISTSERV.UMD.EDU
 Sent: Sunday, April 22, 2012 6:37 PM
 Subject: Re: [ECOLOG-L] Invasion, or progression?


 Hi

 I am a chemist and not an ecologist but I'm very interested in this thread
 since I enjoy the wetlands area close to Sacramento near the Davis Yolo
 Causeway. I wondered and am interested in this invasive or progression type
 question. I saw that there was a species called Purple Loosestrife (Lythrum
 salicaria) that was introduced in the 1800s (?) and is a wetland flower
 that has invaded wetlands. I suppose my question is how far do we go back
 to determine if a species is invasive. Is there a time or case when an
 invasive becomes a native? I did see this interesting online article where
 the question asked was Can native species become invasive?

 http://ipmsouth.com/2010/11/**23/can-native-species-become-**invasive/http://ipmsouth.com/2010/11/23/can-native-species-become-invasive/

 Thanks. Ling

 Ling Huang
 Sacramento City 

Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-26 Thread David L. McNeely
Well, several responses have answered in the affirmative so far as natives 
becoming invasive, with examples.  Raccoons and Eastern Red Cedar come to mind 
as examples mentioned so far.  I won't comment further here on my thoughts 
about them. 
 
So far as When do invasives become native?:  What about when people who never 
knew them as exotics are the oldest people looking.  That would make Russian 
Thistle and both species of Tamarisk now native in the western U.S.  But, there 
are control programs for Tamarisk.  So far as I know, only farmers and ranchers 
make any effort to control Russian thistle (tumbleweed). 

Another example of exotic to native so far as function is concerned might be 
common carp in North America.  Which brings to mind that a fair number of 
exotic fishes have been planted in locales where they have become an accepted 
(and even welcomed) part of the local fish fauna.  Some of them are sports 
fishes. Among these are several trouts from North America transplanted to 
other parts of North America, Europe, Africa, S. America;  Several centrarchids 
from eastern 
North America transplanted to western North America, Africa, S. America;  Brown 
trout from Europe to North America; striped bass from the Atlantic seaboard of 
North America to interior river systems in North America.   
 
If the introduction is on purpose for a supposed benefit, does it still count 
as invasive when it becomes widely established? 

David McNeely

 Wayne Tyson landr...@cox.net wrote: 
 Ecolog,
 
 I am dismayed that there has been so little response to Huang's questions. 
 Perhaps I am wrong in that assumption and they have been. But it seems to me 
 that the questions should be addressed and some conclusions concluded, even 
 if they are two-headed.
 
 I suggest that everyone read the article to which Huang supplied a link. It 
 is not long, nor is it complicated. I suspect that there may be a 
 fundamental flaw in the article's premise, but I will leave that judgment up 
 to my betters . . .
 
 Coincidentally, Joshua Wilson's original post (Invasion or progression?) did 
 not define progression, nor has anyone else, and Wilson has not responded 
 to my request for a definition. I think it is essential that it be defined 
 before his question can be answered. If Josh was just joshing us, or he is 
 incapacitated, I may have to lower his grade from an A+ to, say, a C for 
 mediocrity, due to his unresponsiveness. Are you there, Josh?
 
 I will await the responses from others on the questions by Huang:
 
 1. (When) do invasives become native?
 
 2. Can natives become invasive?
 
 I hope that greater responsiveness will encourage Huang, the chemist, to 
 continue to take his cross-fertilization attempt seriously and not to give 
 up on ecologists.
 
 WT
 
 
 - Original Message - 
 From: ling huang ling.hu...@prodigy.net
 To: ECOLOG-L@LISTSERV.UMD.EDU
 Sent: Sunday, April 22, 2012 6:37 PM
 Subject: Re: [ECOLOG-L] Invasion, or progression?
 
 
 Hi
 
 I am a chemist and not an ecologist but I'm very interested in this thread 
 since I enjoy the wetlands area close to Sacramento near the Davis Yolo 
 Causeway. I wondered and am interested in this invasive or progression type 
 question. I saw that there was a species called Purple Loosestrife (Lythrum 
 salicaria) that was introduced in the 1800s (?) and is a wetland flower that 
 has invaded wetlands. I suppose my question is how far do we go back to 
 determine if a species is invasive. Is there a time or case when an invasive 
 becomes a native? I did see this interesting online article where the 
 question asked was Can native species become invasive?
 
 http://ipmsouth.com/2010/11/23/can-native-species-become-invasive/
 
 Thanks. Ling
 
 Ling Huang
 Sacramento City College
 
 
 --- On Sun, 4/22/12, Amanda Newsom ajnew...@ucdavis.edu wrote:
 
 From: Amanda Newsom ajnew...@ucdavis.edu
 Subject: Re: [ECOLOG-L] Invasion, or progression?
 To: ECOLOG-L@LISTSERV.UMD.EDU
 Date: Sunday, April 22, 2012, 3:40 PM
 
 Very intelligent members of the public have asked me this question when
 they approach me in the field and I have some time to chat. It's a great
 question, because invasions biology is attacked politically on this front,
 so it's one to which professionals really must craft a coherent response in
 friendly conversation.
 
 Another point to consider is the evolutionary history of native vs.
 introduced (non-native) species in any particular system. One of the
 reasons non-natives are of concern is that they do not share evolutionary
 history with the native community, and this contributes to the
 unpredictable biodiversity loss cited by other comments presented here.
  This can also be discussed in light of the homogenization of life on
 earth, because there are many species favored, facilitated, or directly
 cultivated by humans that are now distributed worldwide. Some of these
 species threaten regional biodiversity (Check out the book 

Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-26 Thread Steve Young
I sent a reference to the Brown et al. (2008) paper 
(http://www.bioone.org/doi/abs/10.1614/IPSM-08-082.1) to Huang offline. I think 
many other references were also sent offline.
 
As for Joshua's comment that certain invasive species have led to unforeseen 
benefits, there is a small (?) body of research and commentary on the impact 
that invasive species are having on ecosystem services. The increase in the 
distribution of invasive species is impacting ecosystems and not always to the 
detriment of the system. In fact, articles by Hershner and Havens (2008) 
(http://onlinelibrary.wiley.com/doi/10./j.1523-1739.2008.00957.x/abstract), 
Pattemore and Wilcove (2011) 
(http://rspb.royalsocietypublishing.org/content/279/1733/1597), and others 
would support this premise and have raised considerable debate in other online 
communities. In contrast, one of the biggest issues currently being debated is 
how invasive plant species used for bioenergy production could have significant 
effects if they escape into the local region 
(http://www.nwf.org/News-and-Magazines/Media-Center/Reports/Archive/2012/04-04-12-Growing-Risk.aspx).
 Again, much has to do with how we define an invasive, the context in which 
we're referring to, and the setting we may be working in. I'm not sure if this 
is the direction of the discussion for this thread, but it is something to 
consider. 

Steve


___
Stephen L. Young, PhD
Weed Ecologist
University of Nebraska-Lincoln


-Original Message-
From: Ecological Society of America: grants, jobs, news 
[mailto:ECOLOG-L@LISTSERV.UMD.EDU] On Behalf Of Joshua Wilson
Sent: Thursday, April 26, 2012 8:11 PM
To: ECOLOG-L@LISTSERV.UMD.EDU
Subject: Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or 
progression?

Good evening,

First off, thank you for the wealth of responses, a number of them helped to 
solidify and clarify ideas on this issue.  I had been waiting for all responses 
before I replied with a sort of meta-analysis of what came in.
 The replies were more numerous and substantial than I had anticipated, so 
thank you again.

Now to clarify.  When I mentioned progression, my idea was that an invasive 
species encourages competition, and in some cases extreme and insurmountable 
competition.  I feel that competition without a doubt is beneficial, perhaps 
necessary, for an ecosystem to continue progressing towards a more complex and 
stronger state.

The complication arises when an introduced species or a native species that 
becomes dominant are able to outcompete the other species in the ecosystem to 
the point of the only species able to compete is itself.  In these instances, 
there are various stances to take, some of which I've heard through responses 
(again, thank you).  From the complete control and restoration of native 
(albeit weaker) species, to letting nature run its course. However, my thought 
was that ecosystems are cyclical and self-regulating.  And as Wayne Tyson said, 
we are interrupting and influencing this.  This leads to many more questions.  
With what I've learned so far through this posting, exhaustive studies would be 
needed to determine the best course of action for a particular system or 
species.
 Even then, the needed actions to benefit one species might directly contradict 
the needs of another.  There are multitudes of variables that need to go into 
project planning, not the least of which is *us, *and we cannot foresee the 
ripple effects of what we'll do.

On the other hand, certain invasive species have led to unforeseen benefits.  I 
will mention *Tamarix* *spp.* in this instance.  But even with the detriments 
and benefits, there is a threshold to each.  Likewise, invasive species seem to 
provide species-specific detriments (or benefits).
 One can call it a culling of the weak species and the establishment of 
stronger (which in my mind is necessary for progression), or unfair 
competition, invasive species are not by nature detrimental.

I've rambled far more than I expected to, and not as cohesive as some might 
like.  My knowledge and experiences are limited, hence my original question, 
but I've a sincere interest in these ideas.  Again, I would welcome any 
thoughts, ideas, questions, or comments.  Thank you all ECOLOG, this is a great 
resource for undergrads, post-docs, and interested individuals alike.  Keep it 
up.

Have a good night all,

Josh

On Thu, Apr 26, 2012 at 4:44 PM, Wayne Tyson landr...@cox.net wrote:

 Ecolog,

 I am dismayed that there has been so little response to Huang's questions.
 Perhaps I am wrong in that assumption and they have been. But it seems 
 to me that the questions should be addressed and some conclusions 
 concluded, even if they are two-headed.

 I suggest that everyone read the article to which Huang supplied a link.
 It is not long, nor is it complicated. I suspect that there may be a 
 fundamental flaw in the article's premise, but I will leave

Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-26 Thread David Duffy
I feel that competition without a doubt is beneficial, perhaps necessary,
for an ecosystem to continue progressing towards a more complex and
stronger state.

However, my thought was that ecosystems are cyclical and self-regulating.

native (albeit weaker) species

I am not sure there is much evidence that ecosystems progress towards a
more complex and stronger state, even if we do not ask whether if
competition is beneficial or even a dominant force. Nor is there
evidence, with a few exceptions, that ecosystems are cyclical, much less
self regulating and then only if you carefully pick your scale.  One might
argue that much of ecological theory has been a repeat of the
Gleason-Clements debate, an argument between those who seem life dominated
by random events and those who see homeostasis and orthogenesis, perhaps
with a pinch of Nietzchian der Wille zur Macht thrown in.  This colors
current discussions of invasive species, probably far more than any
confusion over what invasive means.

David Duffy


On Thu, Apr 26, 2012 at 3:11 PM, Joshua Wilson
joshua.m.wils...@gmail.comwrote:

 Good evening,

 First off, thank you for the wealth of responses, a number of them helped
 to solidify and clarify ideas on this issue.  I had been waiting for all
 responses before I replied with a sort of meta-analysis of what came in.
  The replies were more numerous and substantial than I had anticipated, so
 thank you again.

 Now to clarify.  When I mentioned progression, my idea was that an invasive
 species encourages competition, and in some cases extreme and
 insurmountable competition.  I feel that competition without a doubt is
 beneficial, perhaps necessary, for an ecosystem to continue progressing
 towards a more complex and stronger state.

 The complication arises when an introduced species or a native species that
 becomes dominant are able to outcompete the other species in the ecosystem
 to the point of the only species able to compete is itself.  In these
 instances, there are various stances to take, some of which I've heard
 through responses (again, thank you).  From the complete control and
 restoration of native (albeit weaker) species, to letting nature run its
 course. However, my thought was that ecosystems are cyclical and
 self-regulating.  And as Wayne Tyson said, we are interrupting and
 influencing this.  This leads to many more questions.  With what I've
 learned so far through this posting, exhaustive studies would be needed to
 determine the best course of action for a particular system or species.
  Even then, the needed actions to benefit one species might directly
 contradict the needs of another.  There are multitudes of variables that
 need to go into project planning, not the least of which is *us, *and we
 cannot foresee the ripple effects of what we'll do.

 On the other hand, certain invasive species have led to unforeseen
 benefits.  I will mention *Tamarix* *spp.* in this instance.  But even with
 the detriments and benefits, there is a threshold to each.  Likewise,
 invasive species seem to provide species-specific detriments (or benefits).
  One can call it a culling of the weak species and the establishment of
 stronger (which in my mind is necessary for progression), or unfair
 competition, invasive species are not by nature detrimental.

 I've rambled far more than I expected to, and not as cohesive as some might
 like.  My knowledge and experiences are limited, hence my original
 question, but I've a sincere interest in these ideas.  Again, I would
 welcome any thoughts, ideas, questions, or comments.  Thank you all ECOLOG,
 this is a great resource for undergrads, post-docs, and interested
 individuals alike.  Keep it up.

 Have a good night all,

 Josh

 On Thu, Apr 26, 2012 at 4:44 PM, Wayne Tyson landr...@cox.net wrote:

  Ecolog,
 
  I am dismayed that there has been so little response to Huang's
 questions.
  Perhaps I am wrong in that assumption and they have been. But it seems to
  me that the questions should be addressed and some conclusions concluded,
  even if they are two-headed.
 
  I suggest that everyone read the article to which Huang supplied a link.
  It is not long, nor is it complicated. I suspect that there may be a
  fundamental flaw in the article's premise, but I will leave that judgment
  up to my betters . . .
 
  Coincidentally, Joshua Wilson's original post (Invasion or progression?)
  did not define progression, nor has anyone else, and Wilson has not
  responded to my request for a definition. I think it is essential that it
  be defined before his question can be answered. If Josh was just joshing
  us, or he is incapacitated, I may have to lower his grade from an A+ to,
  say, a C for mediocrity, due to his unresponsiveness. Are you there,
 Josh?
 
  I will await the responses from others on the questions by Huang:
 
  1. (When) do invasives become native?
 
  2. Can natives become invasive?
 
  I hope that greater responsiveness will 

Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression?

2012-04-26 Thread Martin Meiss
How about if we consider that invaders have become native when all efforts
to eradicate them are futile?

Martin M. Meiss


2012/4/26 David Duffy ddu...@hawaii.edu

 I feel that competition without a doubt is beneficial, perhaps necessary,
 for an ecosystem to continue progressing towards a more complex and
 stronger state.

 However, my thought was that ecosystems are cyclical and self-regulating.

 native (albeit weaker) species

 I am not sure there is much evidence that ecosystems progress towards a
 more complex and stronger state, even if we do not ask whether if
 competition is beneficial or even a dominant force. Nor is there
 evidence, with a few exceptions, that ecosystems are cyclical, much less
 self regulating and then only if you carefully pick your scale.  One might
 argue that much of ecological theory has been a repeat of the
 Gleason-Clements debate, an argument between those who seem life dominated
 by random events and those who see homeostasis and orthogenesis, perhaps
 with a pinch of Nietzchian der Wille zur Macht thrown in.  This colors
 current discussions of invasive species, probably far more than any
 confusion over what invasive means.

 David Duffy


 On Thu, Apr 26, 2012 at 3:11 PM, Joshua Wilson
 joshua.m.wils...@gmail.comwrote:

  Good evening,
 
  First off, thank you for the wealth of responses, a number of them helped
  to solidify and clarify ideas on this issue.  I had been waiting for all
  responses before I replied with a sort of meta-analysis of what came in.
   The replies were more numerous and substantial than I had anticipated,
 so
  thank you again.
 
  Now to clarify.  When I mentioned progression, my idea was that an
 invasive
  species encourages competition, and in some cases extreme and
  insurmountable competition.  I feel that competition without a doubt is
  beneficial, perhaps necessary, for an ecosystem to continue progressing
  towards a more complex and stronger state.
 
  The complication arises when an introduced species or a native species
 that
  becomes dominant are able to outcompete the other species in the
 ecosystem
  to the point of the only species able to compete is itself.  In these
  instances, there are various stances to take, some of which I've heard
  through responses (again, thank you).  From the complete control and
  restoration of native (albeit weaker) species, to letting nature run its
  course. However, my thought was that ecosystems are cyclical and
  self-regulating.  And as Wayne Tyson said, we are interrupting and
  influencing this.  This leads to many more questions.  With what I've
  learned so far through this posting, exhaustive studies would be needed
 to
  determine the best course of action for a particular system or species.
   Even then, the needed actions to benefit one species might directly
  contradict the needs of another.  There are multitudes of variables that
  need to go into project planning, not the least of which is *us, *and we
  cannot foresee the ripple effects of what we'll do.
 
  On the other hand, certain invasive species have led to unforeseen
  benefits.  I will mention *Tamarix* *spp.* in this instance.  But even
 with
  the detriments and benefits, there is a threshold to each.  Likewise,
  invasive species seem to provide species-specific detriments (or
 benefits).
   One can call it a culling of the weak species and the establishment of
  stronger (which in my mind is necessary for progression), or unfair
  competition, invasive species are not by nature detrimental.
 
  I've rambled far more than I expected to, and not as cohesive as some
 might
  like.  My knowledge and experiences are limited, hence my original
  question, but I've a sincere interest in these ideas.  Again, I would
  welcome any thoughts, ideas, questions, or comments.  Thank you all
 ECOLOG,
  this is a great resource for undergrads, post-docs, and interested
  individuals alike.  Keep it up.
 
  Have a good night all,
 
  Josh
 
  On Thu, Apr 26, 2012 at 4:44 PM, Wayne Tyson landr...@cox.net wrote:
 
   Ecolog,
  
   I am dismayed that there has been so little response to Huang's
  questions.
   Perhaps I am wrong in that assumption and they have been. But it seems
 to
   me that the questions should be addressed and some conclusions
 concluded,
   even if they are two-headed.
  
   I suggest that everyone read the article to which Huang supplied a
 link.
   It is not long, nor is it complicated. I suspect that there may be a
   fundamental flaw in the article's premise, but I will leave that
 judgment
   up to my betters . . .
  
   Coincidentally, Joshua Wilson's original post (Invasion or
 progression?)
   did not define progression, nor has anyone else, and Wilson has not
   responded to my request for a definition. I think it is essential that
 it
   be defined before his question can be answered. If Josh was just
 joshing
   us, or he is incapacitated, I may have to lower his grade from an A+
 to,
   say,