From:    Joel Hanes                             
To:      All                                    Msg #51, Mar-27-93 12:35PM
Subject: FAQ:  What, if anything, is "Darwinism"

Organization: Amdahl Corporation  Sunnyvale California
From: jjh00@diag.amdahl.com (Joel Hanes)
Message-ID: <7cb6024S3cWK01@juts.ccc.amdahl.com>
Reply-To: jjh00@diag.amdahl.com
Newsgroups: talk.origins

From time to time on talk.origins, new posters attempt
to refute one or another absurd cariacature of evolutionary
thought that they call "Darwinism".

One possible way of addressing such deluded postings is to
present a correct outline of the ideas that constitute
genuine Darwinism.  I hope that this incipient FAQ will grow
into just such an outline.

This first version of the FAQ consists simply of quotes
from Mayr's _One_Long_Argument_.   I intend to add further
material as I encounter it in my reading -- (I suspect, for
example, that S.J. Gould's _Ever_Since_Darwin_ will yield
some good stuff, but right now my copy is in one of the
boxes of books in the garage.)

 I hereby solicit contributions from the t.o irregulars --
preferrably brief epitomes of Darwin's theories in the form of
attributed citations from the writings of Charles Darwin
himself, or those of other prominent evolutionary scientists.

Critiques, suggestions, and flames are all welcome.
Thank you for your support.

Here, then, is Version 1.1 of the "What is Darwinism" FAQ:

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[last modified 27 March 1993 by jjh]

In _One_Long_Argument_[1], Ernst Mayr (evolutionary
biologist, and originator of the Biological Species Concept)
summarizes Darwin's theories, and traces the history of their
acceptance by the world scientific community. 

In the Preface , he begins:
 
   `A modern evolutionist turns to Darwin's work again and
    again.  This is not surprising, since the roots of all
    our evolutionary thinking go back to Darwin.  Our current
    controversies very often have as their starting point some
    vagueness in Darwin's writings or a question Darwin was
    unable to answer owing to the insufficient biological
    knowledge available in his time.  But one returns to 
    Darwin's original writings for more than historical
    reasons.  Darwin frequently understood things far more
    clearly than both his supporters and his opponents, 
    including those of the present day.'

In Chapter Four, "Ideological Opposition to Darwin's Five Theories",
Mayr summarizes "Darwin's Theory", or "Darwinism", thus:

    `In both scholarly and popular literature one frequently
     finds references to "Darwin's theory of evolution", as
     though it were a unitary entity.  In reality, Darwin's 
     "theory" of evolution was a whole bundle of theories,
     and it is impossible to discuss Darwin's evolutionary
     thought constructively if one does not distinguish its
     various components. 

     ... The term "Darwinism", ... has numerous meanings
     depending on who has used the term and at what period.
     A better understanding of the meaning of this term is
     only one reason to call attention to the composite  
     nature of Darwin's evolutionary thought.

     ... One particulary cogent reason why Darwinism cannot   
     be a single monolithic theory is that organic evolution
     consists of two essentially independent process, as we    
     have seen: transformation in time, and diversification
     in ecological and geographical space.  The two processes
     require a minimum of two entirely independent and very
     different theories. 

     ... I consider it necessary to dissect Darwin's conceptual
     framework of evolution into a number of major theories that
     formed the basis of his evolutionary thinking.  For the
     sake of convenience, I have partitioned Darwin's
     evolutionary pardigm into five theories, but of course
     others might prefer a different division.  The selected
     theories are by no means all of Darwin's evolutionary
     theories; others were, for instance, sexual selection, 
     pangenesis, effect of use and disuse, and character
     divergence.  However when later authors referred to Darwin's
     theory thay invariably had a combination of some of the
     following five theories in mind:

     (1)  _Evolution_as_such_.  This is the theory that the world
          is not constant or recently created nor perpetually
          cycling, but rather is steadily changing, and that
          organisms are transformed in time.

     (2)  _Common_descent_.  This is the theory that every group
          of organisms descended from a common ancestor, and
          that all groups of organisms, including animals, plants,
          and microorganisms, ultimately go back to a single origin
          of life on earth.

     (3)  _Multiplication_of_species_.  This theory explains the
          origin of the enormous organic diversity.  It postulates
          that species multiply, either by splitting into daughter
          species or by "budding", that is, by the establishment
          of geographically isloated founder populations that
          evolve into new species.

     (4)  _Gradualism_.  According to this theory, evolutionary
          change takes place through the gradual change of
          populations and not by the sudden (saltational)
          production of new individuals that represent a new
          type.

     (5)  _Natural_selection_.  According to this theory,  
          evolutionary change comes about throught the abundant
          production of genetic variation in every generation.
          The relatively few individuals who survive, owing
          to a particularly well-adapted combination of
          inheritable characters, give rise to the next
          generation.'

--------------------------------------------------

Let me (Joel Hanes) try to anticipate some of the possible
reactions from modern-day Darwinists, and their opponents.  

At first blush, (4) _Gradualism_ seems like it might conflict
with Gould & Eldredge's "punctuated equilibrium" theory;
but on closer examination, not so.  Mayr is not claiming
(and apparently Darwin did not claim) that evolutionary change
is slow and continuous -- only that it does *not* proceed by
"jumps" _in_a_single_generation_ (what Mayr calls "saltational"
change).  That is, despite the distortions of some anti-evolutionists,
Darwin explictly did not think that evolution proceeds by the
production of "hopeful monsters" -- neither Darwin nor his
scientific followers think that a fully-dinosaur parent
gave birth to fully-bird progeny.  Rather, the change took
place in a series of intermediate, perhaps nearly insensible,
steps in successive generations.  Note that change over a 
thousand generations of any species appears as "sudden" or
"abrupt" change in the fossil record, because a thousand generations
is such an infinitesimally small fraction of Earth's history.

(5) _Natural_selection_, doesn't account for some of the kinds
of variation that we see in species -- but you'll notice that
Mayr (and apparently Darwin) don't say that it must.  Some
biologists after Darwin distorted the theory of natural 
selection into the doctrine of "strict adaptionism", in which
every feature of every organism is held to be produced by
natural selection, and thus some explanation of why the
feature is selected for is required.  But Darwin didn't say
that _all_ selection is natural (adaption) selection -- in
fact, you'll notice that Mayr lists sexual selection as another
source of change in Darwin's own theories.  Point (5) doesn't
claim that _all_ change comes about by natural selection, but
only that natural selection is the source of _some_ change, and
can explain why adaptive change occurs.  Modern biologists
have proposed other mechanisms for change -- neutral selection,
genetic drift, the "founder effect", etc..  None of these
contradict the idea of natural selection -- they augment it,
as additional mechanisms for genetic change over time.