Saturday, March 6, 2010
Smooth v. Erratic Evolution
On pages 29-30, Jerry Coyne uses the example of the marine organism Globorotalia conoidea to explain how tracing a single fossil species can help geologists to see how that species evolved. In this particular example, the number of chambers in the final whorl of the plankton shell decreases gradually and smoothly over time. However, Coyne goes on to say that "evolution, though gradual, need not always proceed smoothly, or at an even pace." What factors determine how smoothly or erratically evolution occurs in a particular species? Provide examples and compare and contrast the environmental conditions in which a certain species can undergo smooth evolution and erratic evolution.
Posted by Sara Bahmanyar at 10:00 PM