There are, however, gaps in the fossil record that remain controversial both in the scientific and philsophical communities. The religious right believes that the world is relatively young and the fossil record is only a few thousand years old, just pre-Noah flood. Gaps in the fossil record tend to suggest abrupt transitions in species. There are, however, several reasons for gaps/abrupt transitions in the fossil record that are scientific in nature:
Logistical -- there is clear bias in the record because many species are underpresented or have not yet been found. Not all organisms preserve the same, and many simply were never preserved. Not all bones survive well, some are scavanaged- indeed it is rare to find fossils at all.
Statistical -- When only a few species are found of an organism it is hard to decide just how representative they are of the species in total. It takes quite a number of fossils to make a picture of the species over time.
Climatological -- Depending on the extinction event, the animal's death, etc. conditions may or may not have been appropriate for preservation. The climnate has changed many, many times; often resulting in a lack of fossils rather than a dearth (O'Neill, 2010).
While it seems that abrupt changes are the rule rather than the exception, there simply may be unfound fossils, or evolution could work in a way that causes species to remain stagnant for a time, but move quickly -- in other works, the punctuated version is more correct (The Quote Mine Project, 2006).
REFERENCES
"The Quote Mine Project." (2006). Talk Origons Archive. Retrieved from:
http://www.talkorigins.org/faqs/quotes/mine/part3.html
Understanding Evolution." January 2006. University of California Berkeley. Retrieved from:
http://evolution.berkeley.edu/.
Gould and Eldredge. (1972). Puntuated Equilibria: An Alternative to Phyletic Gradualism. In T.E. Schopf, Models in Paleobiolgy (pp. 82-115). San Francisco, CA: Freeman, Cooper and Company.
O'Neil, D. (2010). Interpreting the Fossil Record. Palomar.edu. Retrieved from:
http://anthro.palomar.edu/time/time_1.htm
Pojeta, J. And Springer, D. (2005). Evolution and the Fossil Record. AGIWEB.ORG. Retrieved
from: http://www.agiweb.org/news/evolution/index.html
