The Evolution of Animals
Please see the extensive Web links on the Biology 404 HOL Chapter 4 Website
These include a link to Dr. Pamela Gore's helpful lecture notes on the
Precambrian-Cambrian Transition.
1. How are sponges like the single-celled protists known as choanoflagellates and, if they are so are similar to choanoflagellates, why are they considered members of the clade, Metazoa?
2. Compare and contrast a sponge, cnidarian, and a worm, such as a flatworm.
3. What are Hox genes? How are they used by animals?
4. Recent evidence has suggested a Precambrian interval of glaciation colder than anything since. It is thought to have occurred from about 750 to 600 MYA and has been dubbed "Snowball Earth" or "Slushball Earth." Explain competing hypotheses for how these conditions could be related to the evolution of animals either during this interval or after conditions warmed back up.
[Go to Previous: Review Questions for HOL Chapter 3]
[Go to Next: Review Questions for HOL Chapter 5]
[Go to History of Life listing for Chapter 4]
[Return to Honors 301T Home Page]