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Physiology InFocus: Novel Technologies in Physiology and Medicine
Experimental Evolution as a Tool of Physiological Analysis

One of the most traditional problems in physiology is to seek the functional purpose of a particular feature of an organism.  A traditional way to answer this question is to tamper with that feature and examine the consequences for the organism, where this tampering can be achieved by surgery, pharmacology, mutation, or genetic engineering.  An alternative approach is to look for the comparative correlates of such features.  E.g. cave dwelling animals tend to evolve blindness and atrophied retinas, suggesting the role of tissues that receive ambient photons in vision. 

Recently, evolutionary physiologists have developed what amounts to a synthesis of these two approaches:  imposing selection for particular physiological attributes on large laboratory populations for multiple generations, and analyzing the products of such selection.  This approach has many attractive features for physiological analysis: (a) appropriate controls are easily found – unselected control populations; (b) replication of the evolving populations, to control for accidental genetic fixation of confounded physiological changes; (c) the prospect of wholesale repetition of the evolutionary experiment, both by the same experimenter and by independent laboratories; (d) the use of genomic methods of analysis to identify loci involved in the physiological change; (e) selection for enhancement of function, which avoids the kind of correlated deleterious effects that arises with destruction of physiological features by surgery, mutation, etc.

The experimental systems covered by these talks range from E. coli to Drosophila to rats to mice.  Each of these investigators has been successfully combining selection with physiological research for some years, and as such are well-suited to conveying the power of this experimental approach for the analysis of physiological mechanisms.