In this activity, students use DNA sequences from marine mollusks to construct phylogenetic trees. This activity uses mollusks as model organisms to introduce phylogeny and the importance of evolutionary relationships in modern taxonomy.

In Part 1, students learn how DNA can be used to study evolutionary relationships. Part 2 introduces an online software (MAFFT) for generating DNA sequence alignments and phylogenetic trees. In Parts 3 and 4, students build and explore phylogenetic trees of different mollusks. In the optional inquiry-based extension, students apply the techniques they’ve learned to explore evolutionary relationships among species of their choosing.

This activity was designed to accompany the Click & Learn Sorting Seashells, in which students construct an evolutionary tree of the same mollusk species based on morphological characteristics.

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