Phylogenetics Worksheet:
Name: ____________________
1. Did the construction of the phylogenetic tree based solely on the 14 living Caminalcules
change the way you would have grouped the Caminalcules species in your taxonomic
classification (chart) if you had it to do over? What does this suggest about
classification based strictly on similarity versus evolutionary relationship?
2. Did the phylogeny of the 14 living Caminalcules you made in week 1 based on their
morphological similarity differ from their relationships in the phylogenetic tree with all 71
Caminalcules, both living and fossil? Which do you have more confidence in? What do
fossils add to our understanding of Caminalcules evolution in terms of rates and
direction of evolutionary change?
3. Identify the most recent common ancestor of any two species. (answer should read like
“species 5 is the most recent ancestor of species 2 and species 4”)
4. You will notice that some lineages branched many times in a relatively short time period
and are represented by many living species. Provide an example from your phylogenic
tree of this rapid diversification.
5. Some lineages change very little over time. A good example of this would be “living
fossils” like sharks, the horseshoe crab, or cockroaches whose fossils. Provide an
example from your phylogenic tree of evolutionary stasis. Discuss what types of
ecological conditions might result in this sort of long-term evolutionary stasis.
6. Some Caminalcules went extinct without leaving descendents. In the real world, what
characteristic of a species life history (not of their environment) might increase the
probability of that species going extinct?
7. Find two examples of convergent evolution among the Caminalcules. This means
finding cases where two or more species have a similar characteristic that evolved
independently. The wings of bats, birds and bees are an example of convergence since
the three groups did not inherit the characteristic from their common ancestor. Write
your answers in complete sentences (e.g. “Species x and y both have ____ but their
most recent common ancestor, z, did not”).
8. Describe two examples of vestigial structures that you can find among the
Caminalcules. These are structures that have become reduced over time to the point
that they are virtually useless. Ear muscles and the tail bones are examples of vestigial
structures in humans.
Explain how vestigial structures provide clues about a species’ evolutionary past.
Illustrate your argument with vestigial structures found in humans or other real species.