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Tree thinking cannot taken for granted: challenges for teaching phylogenetics.

Sandvik H - Theory Biosci. (2008)

Bottom Line: Unfortunately, however, this does not imply that tree thinking can be taken for granted.It is quite common for students to encounter anthropocentric trees and even trees containing stem groups and paraphyla.While these biases originate from the unconscious philosophical assumptions made by authors, the findings suggest that presenting unbiased evolutionary trees in biological publications is not merely a philosophical virtue but has also clear practical implications.

View Article: PubMed Central - PubMed

Affiliation: Institutt for Biologi, Universitetet i Tromsø, 9037, Tromsø, Norway. hanno@evol.no

ABSTRACT
Tree thinking is an integral part of modern evolutionary biology, and a necessary precondition for phylogenetics and comparative analyses. Tree thinking has during the 20th century largely replaced group thinking, developmental thinking and anthropocentrism in biology. Unfortunately, however, this does not imply that tree thinking can be taken for granted. The findings reported here indicate that tree thinking is very much an acquired ability which needs extensive training. I tested a sample of undergraduate and graduate students of biology by means of questionnaires. Not a single student was able to correctly interpret a simple tree drawing. Several other findings demonstrate that tree thinking is virtually absent in students unless they are explicitly taught how to read evolutionary trees. Possible causes and implications of this mental bias are discussed. It seems that biological textbooks can be an important source of confusion for students. While group and developmental thinking have disappeared from most textual representations of evolution, they have survived in the evolutionary tree drawings of many textbooks. It is quite common for students to encounter anthropocentric trees and even trees containing stem groups and paraphyla. While these biases originate from the unconscious philosophical assumptions made by authors, the findings suggest that presenting unbiased evolutionary trees in biological publications is not merely a philosophical virtue but has also clear practical implications.

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Related in: MedlinePlus

Example phylogeny, where letters symbolise species. Not a single student (n = 31) was able to give the correct answer to the question “which species is/are most closely related to species B”
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Related In: Results  -  Collection


getmorefigures.php?uid=PMC2254468&req=5

Fig1: Example phylogeny, where letters symbolise species. Not a single student (n = 31) was able to give the correct answer to the question “which species is/are most closely related to species B”

Mentions: “Given the following evolutionary tree [reproduced in Fig. 1], where letters symbolise species: which species is (are) most closely related to species B?”1(The correct answer was “C, D, E and F”.)


Tree thinking cannot taken for granted: challenges for teaching phylogenetics.

Sandvik H - Theory Biosci. (2008)

Example phylogeny, where letters symbolise species. Not a single student (n = 31) was able to give the correct answer to the question “which species is/are most closely related to species B”
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2254468&req=5

Fig1: Example phylogeny, where letters symbolise species. Not a single student (n = 31) was able to give the correct answer to the question “which species is/are most closely related to species B”
Mentions: “Given the following evolutionary tree [reproduced in Fig. 1], where letters symbolise species: which species is (are) most closely related to species B?”1(The correct answer was “C, D, E and F”.)

Bottom Line: Unfortunately, however, this does not imply that tree thinking can be taken for granted.It is quite common for students to encounter anthropocentric trees and even trees containing stem groups and paraphyla.While these biases originate from the unconscious philosophical assumptions made by authors, the findings suggest that presenting unbiased evolutionary trees in biological publications is not merely a philosophical virtue but has also clear practical implications.

View Article: PubMed Central - PubMed

Affiliation: Institutt for Biologi, Universitetet i Tromsø, 9037, Tromsø, Norway. hanno@evol.no

ABSTRACT
Tree thinking is an integral part of modern evolutionary biology, and a necessary precondition for phylogenetics and comparative analyses. Tree thinking has during the 20th century largely replaced group thinking, developmental thinking and anthropocentrism in biology. Unfortunately, however, this does not imply that tree thinking can be taken for granted. The findings reported here indicate that tree thinking is very much an acquired ability which needs extensive training. I tested a sample of undergraduate and graduate students of biology by means of questionnaires. Not a single student was able to correctly interpret a simple tree drawing. Several other findings demonstrate that tree thinking is virtually absent in students unless they are explicitly taught how to read evolutionary trees. Possible causes and implications of this mental bias are discussed. It seems that biological textbooks can be an important source of confusion for students. While group and developmental thinking have disappeared from most textual representations of evolution, they have survived in the evolutionary tree drawings of many textbooks. It is quite common for students to encounter anthropocentric trees and even trees containing stem groups and paraphyla. While these biases originate from the unconscious philosophical assumptions made by authors, the findings suggest that presenting unbiased evolutionary trees in biological publications is not merely a philosophical virtue but has also clear practical implications.

Show MeSH
Related in: MedlinePlus