l'Arbre du Vivant

Séminaire de philosophie de la biologie
organisé par M-C Lorne et F. Merlin
bi-mensuel, les jeudis de 14h00 à 15h30

Chers amis,

la prochaine séance du séminaire PhilBio (IHPST) se tiendra le jeudi 03 mai '07.
Eric BAPTESTE (IHPST) nous parlera de "Pourquoi l'évolutionnisme
devrait se préparer à se passer de l'Arbre du Vivant?"

Vous trouvez bientôt le résumé de son intervention dans le site du
séminaire www.philbio.info.

Pour le moment, voici une référence intéressante et l'abstract de l'article:

Doolittle WF, Bapteste E.  Pattern pluralism and the Tree of Life hypothesis.
Proc Natl Acad Sci U S A. 2007 Feb 13;104(7):2043-9.

Department of Biochemistry and Molecular Biology, Dalhousie
University, Halifax, NS, Canada B3H 1X5
Contributed by W. Ford Doolittle, December 5, 2006 (received for
review November 11, 2006)

Darwin claimed that a unique inclusively hierarchical pattern of
relationships between all organisms based on their similarities and
differences [the Tree of Life (TOL)] was a fact of nature, for which
evolution, and in particular a branching process of descent with
modification, was the explanation. However, there is no independent
evidence that the natural order is an inclusive hierarchy, and
incorporation of prokaryotes into the TOL is especially problematic.
The only data sets from which we might construct a universal hierarchy
including prokaryotes, the sequences of genes, often disagree and can
seldom be proven to agree. Hierarchical structure can always be
imposed on or extracted from such data sets by algorithms designed to
do so, but at its base the universal TOL rests on an unproven
assumption about pattern that, given what we know about process, is
unlikely to be broadly true. This is not to say that similarities and
differences between organisms are not to be accounted for by
evolutionary mechanisms, but descent with modification is only one of
these mechanisms, and a single tree-like pattern is not the necessary
(or expected) result of their collective operation. Pattern pluralism
(the recognition that different evolutionary models and
representations of relationships will be appropriate, and true, for
different taxa or at different scales or for different purposes) is an
attractive alternative to the quixotic pursuit of a single true TOL.

La séance se tiendra de 14h à 15h30 dans la Grande Salle de l'IHPST.