borbor@cuisun.unige.ch (BORIS Borcic) (06/16/91)
Larry Moran said,
"It is a common misconception among non-biologists that evolution is
associated with morphological change. Such a misconception is fostered
by the fossil evidence that emphasizes such change."
I (Boris Borcic) commented,
"I am no biologist, but... isn't this a bit too dogmatic ? It is
certainly true that non-biologists show a bias towards a morphological-
change view of evolution, but calling this bias a _misconception_ is
(I feel) an unwarranted institutionalization of the bias towards the
molecular view of all things biological of _present-day_ biologists
(as a population)."
Larry Morgan replied,
I hope that I'm not being dogmatic in the sense that I am advocating a belief
that is not founded on firm logical ground. In the case of evolution I am
referring to the standard textbook definition which is "a change in the
frequency of genes in a population". Thus I claim that it is a misconception
to assume that morphological change is the only kind of evolution. If Boris
or anyone else has a problem with this then I suggest that they come up with
a better definition of evolution or at least inform the rest of us that they
do not accept the scientific definition.
My incomplete grasp of English is probably at fault, and it appears that I had
misunderstood the original statement; More precisely, I missed the implied
modal quantifier, e.g. the "necessarily" in "It is a misconception that
evolution is [necessarily] associated with morphological change". What I
understood instead was akin to "Morphological change is irrelevent to evolution"
or "It is a systematic (and naive) error to estimate evolution by amount of
morphological change". I'm sure you will appreciate the difference.
As for my def. of evolution, it is generically that of "a gradual change of
state". Please note: 1) That it reduces to your textbook's *provided*that* one
assumes "evolution" to relate to isolated populations and that the state of a
population is the frequency of its genes. 2) [Since we are in the process of
creating firm logical groung by citing Bibles ;-) ] That my definition is one
you can find in common dictionnaries - which presumably reflect a general
consensus.
Larry furthered,
Note that the definition of evolution IS molecular and that it is agreed to
by biologists who presumably should know what they are talking about. Boris,
you admit that you are no biologist and yet you claim that biologists are
"biased" toward a molecular view. It sounds like you are saying that you know
more about biology than the biologists (otherwise you couldn't recognize the
"bias"). How do you justify such a statement?
Is this net.tennis ? Well, I don't know about biology, it is the
evolution of lifeforms I am discussing :-)
In a reply to another poster, Larry also states :
[...] . The problem is that amateurs resent it when experts shoot
down their far-out hypotheses on scientific grounds. These amateurs then
start complaining about the science mafia and how bigoted we all are. What
amazes me is the hubris of some of those amateurs who post to talk.origins
and sci.bio. They seem to assume that they have some insight into evolution
that has never occurred to "narrow-minded" biologists even though these same
biologists have been studying evolution full time for 200 years. Give us a
little credit, eh!
Seriously, your rethorical standing appears perfectly dogmatic to me. It's a
child's play to paraphrase you replacing "evolution"->"creation","the textbook"
by "the Bible", "biologists" by "theologians and priests" etc... You do not even
adress my point (e.g. is there a bias or not) but deny me the right to assess it
because of my status. Isn't it a logical principle that the validity of a
statement is a property of the statement and not one of the person who makes it?
When you "shoot down far-out hypotheses" with no other justification that they
are made by amateurs and that you are the specialist, claiming that you are
doing so "on scientific ground" is (to say the least) a misrepresentation.
Second, I am *not* assuming anything about the set of insights all biologists
(including the narrow-minded) had about evolution during the last 200 years,
but, if indeed "biologists" constitute a community of thought so consensual and
closely connected that you (as a member) can find offense in the idea that an
outsider might assume he has an insight *you* did not consider as if it was
the same thing than to assume he has an insight no biologist ever considered,
then it should be easy for you to demonstrate the fact and be informative
by retracing the past history of said insight - instead of flaming the
outsider.
As for justifying my statement that there is a bias towards the molecular view,
*without* assuming knowledge of biology other than what is according to you,
it is logically sufficient to note that biologists [TM Moran] mean "evolution
of molecules of lifeforms" when they say "evolution of lifeforms".
Whether this bias is reasonable is alltogether a different question, as is
that of its determiners. Please note that we have a different understanding
of what it is to assess a bias. I gather from your responses to the original
poster and to me that a bias is to you the difference of any view to the
expert's view; e.g. a pejorative someone who knows better is free to use
on someone who knows less well. By this definition, the expert's view is
of course devoid of bias. The matter of biasses would moreover be completely
extra-scientific since in a world where everybody shared "the" scientific
view, there would be no biasses.
In contrast, I percieve reasoning about biasses as interesting, not as a tool
to compare own's informed viewpoint to more naive ones, but as a tool to
speculate
about one's own naivety in the areas of best expertise, e.g. when there is no
known or advertised better viewpoint.
======================
I (Boris Borcic) continued,
"Molecular variation per se doesn't strike me as the only and
undisputable foundation for measuring an amount of evolution. Evolution
is an ecological process as well as a molecular one, and it is not
obvious (to me, at least) that a measure of the evolution of a
particular organism/species by what is significant at the molecular
level should be automatically congruent to a measure of the same by what
is significant at the ecological level."
Larry Moran commented,
I don't understand what you mean by "ecological process". But, as I stated
above, you are free to create your own definition of evolution as long as
you tell us about it. We, on the other hand, don't have to agree with you!
Please tell us more about the Boris Borcic non-biologist definition of
evolution.
Here I must question your good faith :-( since the paragraph you cite was
followed by two others you conveniently deleted and where I made my meaning
clear, or at least clearer.
==========================
I (Boris) concluded with,
"Anyway, and whatever, you can't deny that orphan species such as
Coelocanth or Sphaenodon are a remarkable evolutionary phenomenon."
Larry denied:
Oh yes I can! There are lots of examples, such as bacteria and single-celled
eukaryotes, that have an external morphology that has changed little in
several billion years. Look in a biology book under "stromatolites". The
only reason why Coelacanths have attracted attention is because we humans
have a bias towards those animals that are most closely related to ourselves.
Or towards animals that are bigger than a breadbox.
Hummphh... Look, the emphasis in my above statement was on "orphan species"...
and I did say remarkable, not "exceptional"...
"Whatever, you can't deny that orphan species (such as <insert least
favorite here>) are a remarkable evolutionary phenomenon"
How many varieties of stromatolites are currently living ?
BTW, to what size do their colonies grow ?
Larry concludes :
My own personal favorite among organisms that exhibit some "primitive"
characteristics is Pelomyxa palustris, a single-celled eukaryote that shares
some of the characteristics of the first eukaryotes. These characteristics
are over one billion years old. Sorta puts coelacanths to shame doesn't it!
-Larry Moran
I guess Peloxyma palustris is also easy to grow in the lab ?
Look, I am no special fan of coelacanths or "living fossils". My own
personal favorite among exceptional patterns of evolution is convergence,
and my favorites among organisms that exhibit it are Hummingbirds and
Sphingidae. Adults of these two very specialized and extraordinary families
- as compared to their respective phylogenetical neighbors - display
a striking similarity in shape, size, locomotion, nutrition, and,
to a limited extent, thermoregulation and migrating practice.
The observation of a feeding Hummingbird and a feeding Sphinx, hovering in
static flight over some flower with their long buccal instrument dipping in
nectar, tells me these two groups have something particular in common.
(And if you tell e.g. "you ignorant, they are also some bats", I'll say
"ok, add in the bats if you think they belong")
Now one is a bird and the other is an insect. What was their closest common
ancestor like ? How do their molecules compare ?
If your model of evolution implies a state-space for species such that
common factors like the one between Sphinxes and Hummingbirds cannot be
evidenced, I'll say it is incomplete.
If you tell me that such a model is the only
one serious biologists would consider (which I do not believe), I will say
that biologists are not true to observation.
- Boris Borcic
Alice:
The question is whether you can make words mean all those things,
Humpty-Dumpty:
The question is - who is master ! That's all.
-- Lewis Carroll (quoted and backtranslated from memory)