Chapter 28 Lecture Enrichment Ideas
Describe the difference between "naming" (only one scientist gets to "name" a species); "identifying" (anyone can "identify" with a key), and "classifying" (grouping a species with its closest relatives). Yet in common life these are used almost interchangeably. It is important for biology majors to be more careful in their use of these terms.
Students may ask how we can "know" there are many more species yet to be described and named. From time to time, surveys of systematists are made asking how many species they estimate are yet to be described based on their current rate of work and collecting.
Why can't scientists arrive at one classification system (2-kingdoms, 5-kingdoms, now maybe 6-kingdoms!)?
Describing the problems with Aristotle's land-air-sea classification gives some idea of the limitations of some classification schemes. Describe how new research is constantly refining our understanding of the ever-more-complex relationships as new techniques (DNA hybridization, etc.) become available.
Ask students how drug research proceeds; why do they first test rats, then monkeys, before moving to human trials? Describe the predictive power of a phylogeny that is somewhat close to evolutionary similarity.
Note the caveats peppered throughout the text. Only a few years ago, some scientists predicted molecular systematics would provide the ultimate key to objective classification. If students fully comprehend the work of systematics, they will understand that this is a field that fully integrates all other biological knowledge, and there are no simple short cuts to figuring out this million-piece evolutionary puzzle.
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