Unlikely Sister Taxa – a Tree Drawing Activity That Facilitates Students’ Understanding of Analogous and Homologous Structures

 

Malin J Hansen

Advances in Biology Laboratory Education, 2022, Volume 42

https://doi.org/10.37590/able.v42.art29

Supplemental Materials: https://doi.org/10.37590/able.v42.sup29

Abstract

The misconception that organisms with similar morphology are closely related is common among students. While students may memorize the definitions for analogous and homologous structures, many students find it difficult to understand how these terms relate to convergent and divergent evolution. This activity, which can be implemented into either lab or lecture, gives students an introduction to analogous and homologous structures as well as convergent and divergent evolution. It can also be used as a practice in tree thinking and an introduction to multiple sequence alignment. Students first predict the evolutionary relationship between six organisms by constructing a phylogenetic tree that they think best reflects the evolutionary relationship between them. Thereafter students verify their prediction by comparing DNA sequences using an online software. They then discuss reasons why their original prediction may not be correct. The activity can be expanded upon in several ways, which makes it suitable for introductory as well as upper level courses.

Keywords:  phylogeny, evolutionary relationships, analogous and homologous structures, convergent and divergent evolution

Virtual ABLE (ViABLE) (2021)