Lecture - Phylogeny and Protozoa

Choanoflagellate (left), and colony

Traditional Metazoan Phylogeny

January 11 - 27, 2012

So far we have introduced the main animal phyla that we will cover in this course, introduced the basic concepts of cladistics and overall evolutionary view of diversity ("tree thinking"), and we have studied the most basic features of the Protozoa the informal (not taxonomically valid) grouping of protists that have "animal-like" characteristics.

Among the Protozoa, we considered some of the major groups, following the traditional (more like ancient) classification. The current classification has shifted to reflect evolutionary relationships, but in the scope of this class the traditional groupings will suffice.  The groups we considered were the flagellates, the ciliates, and the amoeboeoids.

The flagellates are of special interest since some of its representatives, the choanoflagellates, are considered, mostly based on molecular evidence, as the sister group of metazoa (more metazoa), and probably very similar to our last common ancestor.
We discussed the traditional metazoan phylogeny, and mentioned that the "new" metazoan phylogeny will be discussed over the course of the semester (it's not that new any more).

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