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Conceptualising the
‘Organism’
Ben Smart, ENCAP, PhD
Philosophy and theoretical
biology: … a safari of problems
What a comprehensive answer to this question seems to require is the
negotiation of many smaller philosophical matters:
• to choose between available modes of explanation for the
organic/organism (mechanistic is the most preferable today, but in the past:
vitalistic, animistic,…?)
• issues concerning the constitution of the organism and when it develops
(reduction and emergence)
• organism qua atomism (substance and unity) or a confluence of forces
(process and multiplicity)
• part-whole relationships (to exist in part or in whole)
• Issues of determinism; whether intentions, purposes, agency is causally
efficacious and deserves to be part of the scientific explanation
For its own sake or an instrument?
Discerning whether the organism is a refined conceptual tool/object for
the life sciences or whether it ought to be the objective of these sciences
to describe and explain this phenomenon?
• Organism as a unit of analysis, for study, … discovery?
• It is a necessary entity for doing evolutionary biology?
• It is necessary to demarcate the individuals to even talk about
species (biological species concept; Mayr, 1942)
• Explanation via Reduction?
• Reduced to fitness propensities (Adaptationist programme)
• Reduced to molecular, biochemical? (Sahotra Sarkar, 1992, 2001,
2002)
Darwin’s ‘One long argument’
for Phylogenetic Evolution (I)
1. Individuals within a species vary.
2. Much individual variation is heritable.
3. Organisms multiply at a rate which exceeds the capacity of their
environment to support them, and so many die.
It follows from (1)-(3) that
4. Organisms that are better suited to their environments will survive and
reproduce at a higher rate than those which are less well suited to their
environments.
Darwin’s ‘One long argument’
for Phylogenetic Evolution (II)
Organism:
• … is a unit of study; a necessary actor of the Darwinian drama: collectives of
homogenous agents bringing about phylogenesis through their struggle for
existence (self-preservation and reproduction)
• … is a unit of analysis; Measuring modification in descent traces the
historical evolution of a species.
“There is grandeur in this view of life, with its several powers, having been
originally breathed into a few forms or into one; and that, whilst this planet has
gone cycling on according to the fixed law of gravity, from so simple a
beginning endless forms most beautiful and most wonderful have been, and
are being, evolved.” (Darwin, 1964, p. 490)
Organism: semantic diffusion
The value or utility of the organism as a concept, may mean different things to
different life sciences: evolutionary and molecular.
“‘Nothing in biology makes sense except in the light of evolution,’ as
Dobzhansky famously quipped….”
“Nevertheless, molecular biology provides a different type of unity, a different
unifying framework for biology at the level of basic physical constitution and
mechanism. This perspective currently cohabits biology in an uneasy tension
with the received framework of [the Modern Evolutionary Synthesis]…
“[and yet] one would be tempted to quip (against Dobzhansky) that much of
the received framework of evolution makes no sense in light of molecular
biology.”
(Sarkar; 2005, pp. 4-5)
Adaptationism (I), The Panglossian
Paradigm
•
Popularised by A.R. Wallace and A. Weismann
•
The “near omnipotence of natural selection” in the formation of the
organic, and fashioned as the best of “all possible worlds”.
•
Voltaire: on Dr. Pangloss: “Things cannot be other than they are…
Everything is made for the best purpose. Our noses were made to carry
spectacles, so we have spectacles. Legs were clearly intended for
breeches, and we wear them.”
•
Adaptationists regard: “natural selection as so powerful and the
constraints upon it so few that direct production of adaptation through its
operation becomes the primary cause of nearly all organic form, function,
and behaviour.”
Adaptationism (II), Character
Studies generally proceed in two phases: 1. “An organism is atomised into [phenotypic] ‘traits’ and these traits are
explained as structures optimally [formed] by natural selection for their
functions.” This is more than a semantic problem; “[o]rganisms are
integrated entities, not collections of discrete objects.
2. “After the failure of part-by-part optimisation, interaction is acknowledge
via the dictum that an organism cannot optimise each part without
imposing expenses on others. The notion of ‘trade-off’ is introduced, and
organisms are interpreted as best compromises among competing
demands” The interaction of parts is retained, and any suboptimality is
explained as contributing to the best possible design of the whole.
(Gould and Lewontin, 1979)
Adaptationism (III), Critique
The faults and the charges:
1. “…failure to distinguish current utility from reasons of origin”
2. “Unwillingness to consider alternatives to adaptive stories”
3. “A reliance upon plausibility alone as a criterion for accepting speculative
tales.”
4. “… for its failure to consider adequately such competing themes as random
fixation of alleles, production of nonadaptive structures by developmental
correlation with selected features, the separability of adaptation and
selection, Multiple adaptive peaks, current utility as an epiphenomenon of
nonadaptive structures”
Adaptationism (IV), illustration
‘How tyrannosaurus used its tiny front legs is a scientific puzzle…’ ???
• It may not be controversial that tyrannosaurus has some use for this part of
their anatomy. Nevertheless: “they are… the reduced product of
conventionally functional homologues in ancestors”, namely: the longer
limbs of allosaurs (1).
• Nonadaptive hypothesis for limb reduction: “… to be a developmental
correlate of allometric fields for relative increase in head and hindlimb size.”
(4) The adaptation of a given form comes apart from selection; current
utility could be an epiphenomenon of that structure.
• Testable: by conventional allometric methods (2). – See Gould 1974, in
General; Lande 1978, on limb reduction.
• This non-adaptive hypothesis is more fruitful than a speculative “just so”
story: such as ‘helping the animal rise from a lying position’. This is both
untestable and based on the plausibility of secondary utility in a
Panglossian world (3).
His masters voice: re-examined
• Gould and Lewontin (1979): “Although Darwin regarded selection as the
most important of evolutionary mechanisms (as do we), no argument from
opponents angered him more than the common attempt to trivialise his
theory by stating that it relied exclusively upon natural selection.”
• Adaptationism: a Darwinian Caricature?
• Darwin (final edition, 1872, p. 395): “As my conclusions have lately been
much misrepresented, and it has been stated that I attribute the
modification of species exclusively to natural selection, I may be permitted
to remark that in the first edition of this work, and subsequently, I placed in a
most conspicuous position – namely at the close of the Introduction – the
following words: “I am convinced that natural selection has been the main,
but not exclusive means of modification.” This has been of no avail. Great is
the power of steady misinterpretation.”
Alternative continental approaches
(I) Character
• That natural selection can explain superficial modifications of the [body
plan] Bauplan that fit structure to environment
• The important steps of evolution, the construction of- and the transition
between Baupläne, must involve some other, and perhaps “internal,”
mechanism.”
OR
• Does not deny that change is mediated by natural selection, but that
constraints restrict possible paths and modes of change so strongly… these
are the most interesting aspect of evolution.
• The basic body plans of organisms are so integrated and so replete with
constraints upon adaptation that conventional styles of selective arguments
can explain little of interest about them.
Alternative continental approaches
(II) Constraints
• Organisms as integrated wholes, fundamentally not decomposable
into independent and separately optimised parts…The form of the
part is a correlated consequence of selection directed elsewhere.
• Adaptation is a secondary utilisation of parts present for reasons of
architecture, development, or history.
“If blushing turns out to be an adaptation affected by sexual selection
in humans, it will not help us to understand why blood is red. The
immediate utility of an organic structure often says nothing at all about
the reason for its being.”
Alternative continental approaches
(III), Riedl
•
Anglo-Continental divide? (e.g. Schindenwolf, 1950; Remane, 1971;
Grassé, 1977)
•
'a law of development (Bildungsgesetz); F. A. Lange, History of
Materialism, (1866- 1873-75)
•
'Life's insatiable tendency to expand itself; W. H. Rolph, Biological
Problem, (1881)
“The living world happens to … exist primarily through universal
requirements which can only be expected under the systems conditions of
complex organisation itself… This is not self-evident, for the whole of the
huge and profound thought collected in the field of morphology, from
Goethe to Remane, has virtually been cut off from modern biology…”
(Riedl, 1978)
Alternative continental approaches
(IV), Nietzsche
“…that the cause of the genesis of a thing and its final usefulness, its
actual employment and integration into a system of purposes, lie toto
caelo apart …”
“However well one has grasped the utility of some physiological organ
(or of a legal institution, a social custom, a political practice, a form in
the arts or in religious cult), one has still not comprehended anything
regarding its genesis”
“The form is fluid but the “meaning” is even more so … Even in the
individual organism things are no different: with each essential growth
of the whole the “meaning” of the individual organs shifts as well…”
Alternative continental approaches
(V), Contra-Spencer et al.
• 'an internal struggle for existence among constituent parts of the
organism'; W. Roux(1881)… for nutrition, expansion, of cells, tissues,
organs
• State metaphor: (R. Virchow; 1858), founder of cellular theory, who
depicted bodies as ‘cellular democracy’ or ‘republic of cells’
“The democratic idiosyncrasy against everything that rules and desires
to rule… indeed it appears to me already to have become lord over
the whole of physiology and the doctrine of life – to its detriment...”
“Under the pressure of that idiosyncrasy one instead places
‘adaptation’ in the foreground, …indeed life itself is defined as an ever
more purposive inner adaptation to external circumstances (Herbert
Spencer)”
Alternative continental approaches
(VI), Developmental Hypotheses
Nietzsche’s Psychology as morphology and Doctrine of the
development of the will to power…
Implications for Ontogenetic Evolution… Phylogenetic?
“…that something extant, something that has somehow or other come
into being, is again interpreted according to new views, monopolised
in a new way, transformed and rearranged for a new use by a power
superior to it; that all happening in the organic world is an
overpowering, a becoming-lord-over; and that in turn, all
overpowering and becoming-lord-over is a new interpreting, an
arranging by means of which the previous “meaning” and “purpose”
must of necessity become obscured or entirely extinguished.”