CONTENT - International Society of Zoological Sciences

ICZ2008 – Abstracts S24
Against Weismann: transformism in French marine stations
(1872-1914)
Josquin Debaz
S24 - Lamarck’s Philosophie Zoologique: 200 years
EHESS – GSPR, 131 boulevard Saint-Michel, 75005 Paris, France
At the end of the 19th Century, a whole generation of French
biologists discovered the transformists thesis with Haeckel's work.
It should be noticed however that the great figures of this
generation were concurrently the actors of the development of
marine stations. For scientists as Perrier, Giard, Delage, Dantec,
Cuénot, the writings of Darwin and Lamarck were going hand in
hand with a new vision of their discipline. All these young scientists
were trained under Henri de Lacaze-Duthiers figure and its
methodological school, which, if they were not opposed to Darwin
as a scientist, did not intend to recognise his theories, outside any
experimental process. Though, It was less the skepticism of their
master than a conception of the discipline which was inherited, and
therefore the goal to anchor transformism in an experimental
practice.
With the arrival of neo-darwinist thesis, the separation of two
designs of heredity reactivate the older debate between epigenesis
and preformation. Those french biologist, as epigenetists, felt
strongly reluctant to Weismann's work. This opposition was often
studied like a fight about inheritance of acquired characters,
without pointing the opposition between two strong reductionisms,
one based on embryo structures, the other on the indissociable
unity of zygote. Marine invertebrates embryology studies, lead in
these marine stations, were central in the debate, even if the two
camps gave opposite readings of them.
The general denomination of this group as 'neo-lamarckian' hide
the great heterogeneity in their positions. Hence, the re-discovery
of Mendel's laws had raised these differences. Crystallising the
group against an interpretation of this event which drive biology
towards the direction they reject. The reaction that can be noticed
in the periodicals, in particular in the scientific Bulletin, was to
widen the field, to publish every different voices, sometimes in
order to give them a higher critic.
Creationist conceptions of teachers (Primary and Secondary
schools teaching biology or language) across nineteen
countries
Pierre Clément 1 and Marie Pierre Quessada 2
1 LEPS-LIRDHIST, Université Lyon 1, France
2 IUFM & Université Montpellier 2, France
Because anti-evolutionist organizations are militating, teaching
evolution at school is currently under contest in several countries.
However no study across many countries was currently available
to analyse the eventual creationist ideas among teachers dealing
with Life and Evolution. Investigating the conceptions about this
topic of 7,050 in-service and pre-service teachers from 19
countries (Europe, Africa and Middle East), we have found
significant proportions of creationist conceptions, and a wide
variation of their amount across countries. The frequency of radical
creationist conceptions is more related to the national economical
level, to the personal degree of believing in God and practising
religion, to the teacher's educational level and to the importance of
teaching Evolution at school, than belonging to a particular
religious group (e.g. Muslim or Christian; Catholic. Protestant or
Orthodox).
The data exposed here are coming from 19 countries, in the
context of the European research project BIOHEAD-Citizen
(Biology, Health and Environmental Education for better
Citizenship: STREPS FP6, Priority 7, n° 506015). We thank all the
colleagues who worked in each country, with the following team
leaders: Farida Khammar (Algeria), Ivette Béré Yoda (Burkina
Faso), Nicos Valanides (Cyprus), Tago Sarapuu (Estonia), Anna-
Lisa Rauma (Finland), Franz Bogner (Germany). Attila Varga
(Hungary), Adriana Valente (Italy), Iman Khalil (Lebanon), Jurga
Turcinaviciene (Lithuania), Paul Pace (Malta), Sabah Selmaoui
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(Morocco), Elwira Samonek-Miciuk (Poland), Graça Carvalho
(Portugazl), Adrienne Kozan (Romania), Mame Seyni Thiaw
(Senegal), Mondher Abrougui (Tunisia), Stephen Tomkins (UK).
We also thank François Munoz and Charline Laurent (team of P.
Clément) for the statistical analyses.
Phenotypic Plasticity: a modern Avatar of Lamarckian thought
Jean R. David
Lab. Evolution, Génomes, Spéciation, CNRS1198 Gif sur Yvette,
France, and Muséum National d’Histoire Naturelle, Département
de Systématique et Evolution. Paris, France
In his ‘Philosophie Zoologique’ (1809), Lamarck proposed that the
diversity of living beings was not the result of a divine creation but
the consequence of a natural process of progressive changes over
time : this is now called biological evolution. Lamarck idea was
obviously right, but changing over generations with modifications
required an explanation of hereditary transmission. Observing that
phenotypes could be modified by the environment, often in an
adaptive direction, he proposed that acquired characters should be
heritable, at least under some conditions. A century later, the
rediscovery of Mendelian heredity proved that acquired characters
were not heritable and, as a consequence, the influence of
Lamarck ideas was more or less forgotten. However, ,the
phenotypic variability in some groups may be spectacular, for
instance in insects like Aphids, while the genome is not modified.
Some researchers remained, however, interested in such
variations, and their study now corresponds to a recognized field of
modern biology, that is phenotypic plasticity. The challenge is to
understand how this plasticity, which is basically non-heritable, can
nonetheless be seen by natural selection, so that phenotypic
plasticity itself may exhibit genetic changes overtime between
populations or species. A classical approach is the Reaction Norm,
that is the response curve of a phenotype along an environmental
gradient. Examples of the diversity of reaction norms will be given,
mostly using the Drosophila model, and showing that in many
cases plasticity has an adaptive significance. Plasticity is an
interaction between the environment and the genome, which by
itself may be selected. For the moment, the genetic mechanisms
of such interactions remain however to be worked out.
Lamarck and Bergson on Progressive Evolution. No need for
an "intelligent designer".
Francis Dov Por
The Hebrew University Jerusalem, Israel
The central progressivist evolutionary theme of Lamarck, is of
equal importance for the zoological philosophers of today. For
Lamarck, progress is the result of the forces of nature, seen as an
inexorable physico-chemical agent. It is not a linear "Scala
Naturae", but a branching evolutionary tree which strives upward
along many ramifications and the primate-human line is only the
most advanced of the different shoots.
Bergson ,in "Evolution Creatrice" which completes its centenary,
saw progressive evolution as irreversible, neither mechanistic, nor
teleological. His "élan vital" is seen by him as a natural force ,yet to
be discovered ,like gravity in its time.
Co-founders of the "modern synthesis", like Dobzhansky and
Huxley, accepted zoological progress without however proposing
any specific mechanism for it. Suspicions of finalism , theology and
of anthropocentrism, led to the presently dominant ultradarwinistic
.dogma .The field has been left open to a pervasive
theological progressivism.
Building of ever higher energy hungry animals and of more energy
efficient ecosystems was emphasized by Lotka (1922) and
recently by Vermeij (2004). Chaisson (2001) sees an evolution of
more complex and more energy dissipating organisms in the open
system of the globe. MEP, the law of maximum entropy production
(Kleidon and Lorenz,2005) is the drive behind animal progress
throughout geological history and the physical expression of
Lamarck's "force de la nature" and Bergson's "élan vital".