Dodson, E. O. and P. Dodson. 1985. Evolution: Process and Product. (Ch. 11, pp. 235-246; Ch. 12, pp. 247-264).

Because of their important consequences to the concept of the biological species, be critical of your reading on isolating mechanisms.

While you are reading these chapters, keep in mind what will be our working definition of the biological species, "one or more populations of organisms, members of which can potentially interbreed to produce fertile offspring and which are reproductively isolated from other such groups."

Questions and Thoughts

1. Just how "good" is our working definition of a species?
2. Are there problems with this definition? If so, are they merely ones of semantics or are there real biological problems, i.e., can it be applied to observable populations in nature?
3. Can we come up with a better definition or should we even really worry about defining a species?
4. Try to create your own definition of a species.
5. Can one definition of a species serve the needs of all branches of science, whether biological or otherwise?