Fish Phylogenetics

Graduate Fellow Tristan Carland & Teacher Partner Tom McElfresh

Phylogenetics, dichotomous keys, and shark diversity.

This activity yields experience with dichotomous keys and a fundamental understanding of DNA based evolutionary trees (phylogenetic trees). The students begin by sorting fishes based on their morphology, formalize this into an evolutionary tree, and this is used as a transition point to DNA based trees (of which there is a live example) and dichotomous keys.

ABSTRACT

This activity yields experience with dichotomous keys and a fundamental understanding of DNA based evolutionary trees (phylogenetic trees). The students observe a genetic algorithm at work, sort fishes based on their morphology, formalize this into an evolutionary tree, and this is used as a transition point to DNA based trees (of which there is a live example).

LEVEL: 9-12^th Grade Biology Students

DURATION: One 50 minute class period can suffice, more than 60 minutes would be better

LEARNING OBJECTIVES:

At the end of this activity students should be able to use a dichotomous key to identify species, infer evolutionary relationships from observations of morphology, draw representative cladograms and understand the basis for molecular studies of evolution.