The Tree-Thinking Challenge

Abstract

In 2000, Jamaica ranked third in the world in murders per capita (2). By the end of 2005, police crime data indicated a record number of annual homicides (63.0 per 100 000 inhabitants), a rate

Understanding Evolutionary Trees

“…2 The quiz used by Meir et al (2007) is available to instructors upon request by email (info@simbio.com). See also the "Tree Thinking Challenge" supplemental quiz by Baum et al (2005). 3 For the purposes of this discussion and regardless of whether this will annoy some specialists, "evolutionary tree," "phylogenetic tree," and "phylogeny" are used interchangeably.…”

“…In this regard, it is not so much the technical aspects of phylogenetic analysis 1 that are of interest but a more practical understanding of what evolutionary trees represent and, at least as important, what they do not represent. As Baum et al (2005) continued, Tree thinking does not necessarily entail knowing how phylogenies are inferred by practicing systematists. Anyone who has looked into phylogenetics from outside the field of evolutionary biology knows that it is complex and rapidly changing, replete with a dense statistical literature, impassioned philosophical debates, and an abundance of highly technical computer programs.…”

“…As Baum et al (2005) recently pointed out, "Phylogenetic trees are the most direct representation of the principle of common ancestry-the very core of evolutionary theory-and thus they must find a more prominent place in the general public's understanding of evolution." In this regard, it is not so much the technical aspects of phylogenetic analysis 1 that are of interest but a more practical understanding of what evolutionary trees represent and, at least as important, what they do not represent.…”

Why coelacanths are not ‘living fossils’

“…In addition, Gould [47] and Kimura [6], have reinforced the idea that evolution is a bushy process that has not stopped in any lineage (see [48] for review). However, the phylogenetic paradigm, also called 'tree-thinking' point of view [49], has encountered difficulties in spreading outside the community of evolutionary researchers [50,51]. The most common misunderstanding of tree-thinking and evolution is the remnant misinterpretation of biodiversity as a 'ladder of progress' [52], a concept that originated in the preevolutionist idea of scala naturae that came from antiquity as it appeared in Figure 1.…”

Penser la biologie dans un cadre phylogénétique

“…Notre expérience d'enseignant-chercheur nous a appris qu'au-delà des difficultés réelles qui existent pour bien comprendre les méthodes employées, peu familières à la plupart des biologistes, le problème récurrent le plus grave est la mauvaise compréhension de la méthode de lecture des arbres. Dans les copies de nos étudiants, nous retrouvons régulièrement des erreurs bien identifiées [14][15][16] qui sont dues à la persistance du concept obsolète d'échelle des êtres (scala naturae) [17]. Malheureusement, ce biais d'interprétation des arbres phylogénétiques est Les arbres phylogénétiques permettent de décrire de façon très synthétique et facile à lire les deux principaux processus de l'évolution : (1) l'anagenèse ou évolution dans une lignée qui est représentée par une branche, et (2) la cladogenèse ou spéciation, qui est représentée par un noeud d'où sont issues deux espèces à partir d'un ancêtre commun.…”