Download Gregynog – 2016

The organism in philosophy
of biology
Andy Jones
PhD Student
Cardiff
Aims
• Introduce the principles of adaptationism
• Discuss Gould and Lewontin’s 1979 article “Spandrels of San Marco
and the Panglossian Paradigm”
• Discuss how symbiosis might relate to adaptationism
• Look at other examples that might alter our conception of
adaptationism.
A problem with identifying organisms?
• “We know that dogs are organisms, while their tails are not. Children
grasp the organism concept readily when confronted with books full
of little blobs and asked “How many sheep are there?” […] Surely,
then, any attempt to claim that species and organisms are problematic
notions, calling out for the attention of philosophers, is just an
example of professionals making work for themselves? […]
scientists really do encounter these problems, and the apparent
obviousness of the intuitive concepts just makes our opening
questions all the more pressing” (Clarke and Okasha, 2013, p.56)
Context – Adaptationism
• Adaptationism: “the claim that natural selection is the only important
cause of the evolution of most nonmolecular traits and that these
traits are locally optimal” (Orzack and Sober, p.6)
• Emphasis on fitness of the organism
• But, not every part of the organism exists in virtue of optimality
Gould and Lewontin – Spandrels of San
Marco and the Planglossian Paradigm
• What are spandrels?
• Spandrels are architectural constraints – they
result from curved edges not being able to connect
with one another.
“we find them easy to understand because we do not
impose our biological biases upon them, […] Since these
spacers must exist, they are often used to ingenious
ornamental effect” (Gould and Lewontin, 1979, p.148)
Spandrels and adaptationism
“evolutionary biologists, in their tendency to focus
exclusively upon immediate adaption to local
environment, do tend to ignore architectural
constraints” (Ibid, p.149)
“One must not confuse the fact
that a structure is used in some
way […] with the primary
evolutionary reason for its
existence and confirmation”
(ibid, p.153)
Just so Stories
“the criteria for
acceptance of a story
are so loose that
many pass without
proper confirmation
[…] But plausible
stories can always be
told” (ibid, p.153-4)
Did Darwin write the origin backwards
• Two arguments in the Origin of the Species.
1. Decent from common ancestry
2. Random variation as the precondition for natural selection
“Darwin faces a choice. Selection has causal priority; common
ancestry has evidential priority” (Sober, 2009, p.10054)
Symbiosis: Bobtail Squid and
Vibrio Fischeri
• Bacteria (10⁹) provide camouflage to the
squid through bioluminescence – it’s
shadow is not detected by it’s prey
• Squid provides nutrients & safety for
the bacteria.
The Squid expels most of the bacteria from its body daily;
Bouchard states this is “most likely to reduce the possibility that the
symbiont would evolve a pathogenic response as many other Vibrio
have done” (Bouchard, 2010, p.631).
So how many organisms are there?
• Are there 2 organisms; 1 organism;
or 10⁹ + 1 organisms?
• Both the squid and v. fischeri
together contribute to the overall
increased fitness; together they are
the unit of selection.
“it is highly improbable, if not impossible, for a fish to acquire five
genes necessary to produce light all “at once” through a single event
occurring in its genome. However, if the fish becomes associated with
a bacterium that already has the five genes, they can be acquired in a
single event” (Combes, 2001, p.566)
Not Just Squids!
• We are in symbiotic relationships
with our own microbiome!
• “In contrast to the squid light
organ, which is colonized with
only a single symbiont, the
mammalian intestine is inhabited
by more than 400 species of
bacteria. Similar to squid,
mammals acquire their microflora
from the environment”
(Hooper, 2004, p.130)
If you’re interested google
TED talk by Rob Knight “How our
microbes make us who we are”
Also, for a more detailed account look
at “Gut feeling – Ventures into the
Microbiome”
Can an organisms contain both living and nonliving components? “every organism is, in a sense, an
• Some termite colonies
construct their mounds in such
a way as to enable ventilation.
• The mound itself acts as a
lung for the colony.
extended organism, unable to exist
without imparting a kind of physiology
to its surroundings as well” (Turner,
2013, p.236)
The relation between the cognitive and the
social.
• These colonies have developed mechanisms to
detect and repair damage to the mound
• According to Turner, the colony has knowledge
of its mound.
• See Turner’s project here.
• Turner’s argument then, is that the organism is
defined by some capacity for cognition, and that
all cognition might be social, then “perhaps the
social dynamic that produces large-scale
homeostasis might illuminate the evolution of
the sophisticated cognitive systems found in
organisms with brains” (Turner, 2013, p.238)
Could non-living components be included as
part of human organisms?
• Take the case of a dialysis machine for someone with kidney failure.
• The machine increases the fitness for the individual using it
analogous to the symbiotic relations between the squid and v. fischeri
or human and microbiome.
• Like the microbiome, the functioning dialysis
machine can be shared between many individuals in a
similar manner to how a donation from a healthy
microbiome can be transplanted to someone with an
unhealthy microbiome.
Living/non-living continued
• Moreover the machine is analogous to the termite mound in the
sense that it is part of the extended physiology of the organism.
• Both the mound and the machine are necessary to the survival of the
organisms they relate to.
• Therefore, if we are to consider that something which is not
genetically part of the organism can be considered as part of the
organism if it increases fitness, and that this might not be biological
itself, then we may have to concede that entities such as dialysis
machines might be considered as part of an organism.
Thank you for Listening!
References
• Bouchard, F. (2010) Symbiosis, lateral function transfer and the (many) saplings of life. Biology
and Philosophy, 25 (pp.623–641)
• Combes, C. (2001) Parasitism: The ecology and evolution of the intimate interactions. Chicago:
University of Chicago Press
• Clarke, E. & Okasha, S. (2013) “Species and Organisms: What are the problems?” In Bouchard, F
and Huneman, P (ed.) From Groups to Individuals: evolution and emerging individuals . USA: MIT
press
• Hooper, L, V. (2004) Bacterial Contributions to Mammalian Gut Development. Trends in
Microbiology. 12 (3) (pp.129-134)
• Gould ,S, J. & Lewontin, R, C. (1979) The Spandrels of San Marco and the Panglossian
Paradigm” Proceedings of the Royal Society of London, Series B, 205 (1161) (pp.581 – 598)
• Sober, E. (2009) Did Darwin Write the Origin Backwards? Proceedings of the National Academy of
Sciences of the United States of America, 106 (1) (pp. 10048-10055)
• Turner, S. (2013) superorganisms and superindividuality: the emergence of individuality in a
social insect assemblage. In Bouchard, F and Huneman, P (ed.) From Groups to Individuals:
evolution and emerging individuals . USA: MIT press