T0E good for study of morphogenesis?
david ford
the field of morphogenesis? Did evolutionary theory help,
hurt, or have no effect on the study of morphogenesis?
Goodwin, Brian C. 1984. "A Relational or Field Theory of
Reproduction and its Evolutionary Implications" in _Beyond
Neo-Darwinism: An Introduction to the New Evolutionary
Paradigm_, Mae-Wan Ho and Peter T. Saunders, eds. (New
York: Academic Press), 376pp., 219-245+. On 220, the first
two paragraphs of the "Introduction" section:
Biology is currently going through a period of
conceptual turmoil whose long-term consequences are
impossible to predict. After a century of almost
continuous analytical development, in which the
empirical and theoretical consequences of the
conceptual scheme established by Darwin and
Weismann have been explored with truly extraordinary
success, those aspects of organic life which are not
readily assimilated within this scheme have returned to
haunt the modern synthesis and to question some of its
basic assumptions. Foremost among these is the
problem of biological form, which includes both the
process whereby organisms of specific morphology are
generated (morphogenesis), and the logical, structural
relationships between organisms of different form
(taxonomy). Neo-Darwinism attempts to assimilate both
of these within its historically based view of biological
process: taxonomy is essentially genealogy, an account
of the chronology of species understood in terms of the
processes of random variation in genotypes and natural
selection of phenotypes; while morphogenesis is the
history of individual development as written in the
genes, themselves seen as the result of an historical
process, morphology then arising by a sort of
self-assembly of gene products into higher-order
structures.
What resists assimilation in this manner is the stubborn
evidence of regularity in, and constraint on, biological
form. Whereas historical processes of the type
described in neo-Darwinism (random variation in
genotypes and selection of the resultant phenotypes by
randomly-varying environments) imply that any
biological form is possible and survival is the only
constraint, the empirical evidence suggests otherwise.
As made clear by the pre-Darwinian rational
morphologists such as Geoffrey St. Hilaire, Cuvier,
Reichert and Owen, the systematic study of comparative
morphology indicates that there are basic structural
constraints which impose limitations of form over
extensive taxonomic groups; examples include the
segmental body plan of the arthropods, the invariant
features of tetrapod limbs, and the structural homologies
that persist despite the great functional changes
occurring in the transformation of the reptilian jaw into
the mammalian middle ear.
Goodwin, B.C. 1989. "Evolution and the generative order"
in _Theoretical Biology: Epigenetic and Evolutionary Order
from Complex Systems_, Brian Goodwin and Peter
Saunders, eds. (Edinburgh: Edinburgh University Press),
89-99. On 98, the "Conclusion" section:
The integration of development and evolution requires
that the real generative processes underlying stable life
cycles be understood. One of the objectives of a
structuralist analysis in biology is to classify the
dynamically stable states of these processes based upon
the general properties of ontogenetic processes, taking
account of all levels of organization involved. Once this
has been achieved, it will be possible to attempt
historical reconstructions of actual phylogenetic
sequences if these answer what are perceived to be
significant questions. But it may well emerge that, if
stable life cycles are in large measure the generic states
of ontogenetic dynamics, then most of the major
biological questions about the relationship of different
taxa to one another, which is what Darwinian evolution
was intended to answer, will receive explanations in
generative terms which are independent of history.
Biology will then have become an exact science.
Goodwin, B.C. 1982. "Development and Evolution"
_Journal of Theoretical Biology_ 97:43-55. On 44-46, the
section "Organization and Transformation":
The physical realm, speaking both broadly and with
extreme simplification, is described by two major types
of theory. The first is concerned with the principles of
organization of various physical systems such as the
laws of mechanics governing the motion of macroscopic
bodies, or the principles of atomic structure and its
transformations which underlie the periodic table of the
elements and their transmutations. Although time is
involved in such theories, since the natural world is seen
as one of process, there is no irreversibility or
directionality in such theories and the allowed
transformations are not constrained by the time
parameter (i.e. there is time-reversal symmetry). Thus
theories of organization in physics essentially describe
the set of forms of mass-energy which are possible,
together with transformations defining how one form
changes into another (i.e. a set of entities and the group
structure which unites them under transformation).
The second type of theory in physics imposes a
constraint on time-dependent processes defining a
preferred direction of change. The most familiar of
these theories is classical thermodynamics, the second
law imposing a principle of temporal asymmetry which
is superordinate over processes with time invariance
such as those described by mechanics, whether classical
or quantum.
The existence of such theories in physics means that the
suject [sic] does not depend upon historical explanations
of natural phenomena, which are based upon
contingencies rather than on law. Thus although it is
perfectly legitimate to consider whether, for example,
carbon or nitrogen appeared first during that dramatic
first phase of current cosmic evolution as described by
the Big Bang cosmological theory, the periodic table of
the elements provides a theory of atomic organization
which is quite independent of such historical
considerations. And the constraints which come from
thermodynamics are compatible with a variety of
possible historical sequences of atomic condensations.
These ultimately depend on contingencies (specific
conditions), many of which can only be guessed at.
Physics is thus based upon the things it can be
reasonably sure about, and so seeks the universal laws
or constraints which define what is possible. That
which actually occurs is then understood as a specific
realization from the set of the possible by the action of
specific conditions, i.e. of contingencies acting within
the constraint of law.
In contrast, contemporary biology does not have a
theory of organismic form analogous to the theory of
atomic structure; that is to say, it does not have a
rational taxonomy. It has only informed guesses at an
historical taxonomy, a genealogy of species. And it
does not have a theory of temporal asymmetry of
organismic transformation: there is no principle of
directed or preferred evolutionary change. As might be
expected of an historical description, there is only an _a
posteriori_ principle of stability of historically given
forms (survival of the fitter organisms). Thus biology
does not have a theory of how organisms are generated,
nor of the principles of their organization, nor of their
transformations; i.e. it does not have a theory of the
origin of species, either ontogenetic or phylogenetic, in
the sense that this would have in physical science. And
it seems that most contemporary biologists are of the
opinion that, _at the level of organsims_ [sic], such a
theory is unlikely ever to emerge.
Historically speaking, this state of affairs is a
post-Darwinian phenomenon. The rational
morphologists of the late 18th and early 19th centuries
were animated by the belief that the biological realm is
one of intelligibility and order, that there are laws of
biological form and organization; and they provided
much evidence from the study of comparative
morphology to support their belief. Among the
conceptual tools which they forged from their empirical
studies were the notion of typical form and the concept
of homology, with which they conducted their search for
evidence of the transformational equivalence of different
morphological structures. Well-known examples are the
homological equivalence of the reptilian jaw and the
mammalian inner ear; and the homological equivalence
of vertebrate limbs, constituting collectively a typical
form called the "pentadactyl limb". It is clear that
Darwin was hostile to the abstract notion of typical
form, which he reified to yield the historical idea of a
"common ancestor", thus bringing genealogical rather
than organizational principles to the fore. This focus on
hereditary (historical) concepts together with Darwin's
preoccupation with organismic adaptation and
competition as the basic "force" underlying natural
selection, laid the foundations for contemporary biology
as a science dominated by content (historical
explanations, contingencies) rather than by form
(universals, laws). Organisms are thus seen as
functional aggregates of adapted parts generated by
genetic programmes, the sediments of contingencies
which have passed the survival test. But these genetic
programmes and how they generate organismic form
remain undefined, and so there is no scientific theory of
morphogenesis in modern biology. It has been argued at
length elsewhere (Webster & Goodwin, 1981_a_, b) that
the very concept of a genetic programme as the directing
agency of embryonic development is highly problematic
and difficult to reconcile with the genetic and
embryological evidence; and that it is a residue of 19th
century romantic idealism which found its way into
biology via Weismann's idea of the germ plasm, an
immortal essence of formative power in organisms.
This substance "has remained in perpeptual [sic]
continuity from the first origin of life"; it is a "highly
complex structure" which has "the power of developing
into a complex organism" (Weismann, 1885). The germ
plasm, which Weismann located in the cell nucleus, is
now identified with the nuclear genome, and its
generative power is ascribed to a "genetic programme".
This whole conceptual development, which brilliantly
saved Darwinism from self-contradiction by centring it
squarely on a theory of inheritance which firmly
excluded Lamarckism, introduced into biology a radical
dualism (characteristic of idealist conceptions) in the
form of the germ plasm-somatoplasm dichotomy and
prevents a resolution of the problem of biological
organization, of which morphogenesis [is] an aspect.
The biological realm will therefore remain unintelligible
and irrational in the scientific sense, centred on the
historical (given) contingencies embedded in undefined
genetic programmes, until this mysterious formative
essence is exorcised and replaced by a scientific theory
of organization. My intention now is to attempt a
description of what this might be like, and aspects of the
research programme which follow from it.
On 55, the article's closing lines:
Thus the view put forward in this paper attempts to shift
the focus from a pre-occupation with the contingent and
the historical, which leaves biology without intelligible
macroscopic structure, to concern with general
principles of organization and transformation which
could give biology a rational taxonomy and a theory of
directed evolutionary change. There is, of course, no
guarantee that this will be possible; but if a rational,
generative biology is ever realized, it will be based upon
developmental processes as the logical, as well as the
historical, origin of species.
Goodwin, B.C. 1989. "A Structuralist Research Programme
in Developmental Biology" in _Theoretical Biology:
Epigenetic and Evolutionary Order from Complex Systems_,
Brian Goodwin and Peter Saunders, eds. (Edinburgh:
Edinburgh University Press), 49-61. On 59-60, the
"Conclusion" section:
In conclusion, a structuralist research programme in
developmental biology has as its objective the
identification of those properties that are generic to
living organisms, arising as inevitable consequences of
the generative principles that operate in life-cycles.
Once these are known, it will be possible to establish the
extent to which the morphological and behavioural
consequences of those principles, observed in different
species, are generic and so establish them as natural
kinds (Webster, 1984). The issue that is at stake here is
that of intelligibility, of rational unification. A
dominant objective in biology has always been to make
sense of the vast sweep of organismic forms. Linnaeus
regarded his taxonomy as a prologomenon to the
understanding of the principles of biological creation.
Darwin transformed this by taking the view that the
reconstruction of actual, contingent genealogical
succession was the procedure that would reveal the plan
of creation, his vision resulting in an historical
unification in terms of common ancestors. But the price
paid for this was intelligibility. The question of a
rational as well as an historical unification remains on
the agenda in biology, and it is this which structuralism
addresses in this context.
Compare
T0E good for taxonomy?: 1973 Fairbairn (a creationist); 1982 Colin
Patterson; 5 November 1981 Patterson
http://www.google.com/groups?selm=b1c67abe.0402161147.29fee40e%40posting.google.com
more Goodwin is in
Essay on Problems with Darwin's Theory of Natural Selection
http://groups.google.com/groups?selm=Pine.LNX.4.10A.B3.10005310900310.17702-100000%40jabba.gl.umbc.edu
"Rev Dr" Lenny Flank
david ford wrote:
> What effect did the advent of evolutionary theory have on
> the field of morphogenesis? Did evolutionary theory help,
> hurt, or have no effect on the study of morphogenesis?
>
What, if anything, is the scientific theory of creation? Has this
scientific theory of creation ever helped, hurt, or have no effect on .
. . . well . . . anything? Anything at all? Anywhere?
===============================================
Lenny Flank
"There are no loose threads in the web of life"
Creation "Science" Debunked:
http://www.geocities.com/lflank
DebunkCreation Email list:
http://www.groups.yahoo.com/group/DebunkCreation
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