- Mayr, Ernst, What Evolution Is, Basic Books, 2001.
- Zimmer, Carl, Smithsonian Intimate Guide to Human Origins, Smithsonian Press,
2008. - http://en.wikipedia.org/
Vocabulary
Cambrian explosion A sudden burst of evolution that may have been triggered by some
environmental changes that made the environment more suitable for a wider variety of
life forms.
extinct Something that does not exist anymore; a group of organisms that has died out
without leaving any living representatives.
mass extinction An extinction when many species go extinct during a relatively short
period of time.
radiometric dating A method to determine the age of rocks and fossils in each layer of
rock; measures the decay rate of radioactive materials in each rock layer.
stromolites Fossils made of algae and a kind of bacteria; some of the oldest fossils on
Earth.
Points to Consider
The next chapter focuses on prokaryotic organisms. Remember, prokaryotes lived on this
planet for two billion years before eukaryotic cells even existed.
- Discuss with your class what you think are some of the characteristics, and some of
the differences, of prokaryotic organisms.
Image Sources
(1) http://en.wikipedia.org/wiki/Image:Isotope_ratio_ms.jpg. Public Domain.(2) http://commons.wikimedia.org/wiki/File:
Huxley_-_Mans_Place_in_Nature.jpg. Public Domain.(3) http://www.bringyou.to/apologetics/HorseEvolution.gif.