A trade-off is a situation that involves exchanging one desirable quality or aspect of something in return for another quality or aspect. In an evolutionary sense it is often presumed that every advantageous alteration of a phenotype comes with a disadvantage since energy invested in one feature cannot be invested in another. The Incredible Shrinking Man is interested in those cases where the biological trade-off involves body size. Large body size may be traded for a number of advantages such as the speed of reproduction, food requirements, time to maturity, stamina, and longevity. In terms of evolution decreased size is often the prize to be paid, which presumes that body size is a desirable quality in itself. However, in many environments smaller body size is not a sacrifice but a gift. Our pre-occupation with growth and bigger size as a quality that needs no further explanation positions the research regarding trade-offs in a dialectical framework, using such words as sacrifice, giving-up and loss vs. gaining, overcoming and winning. It’s difficult to ignore such win or lose linguistics, but we must.
In our series on biological trade-offs we’ll try to figure out a way to engage in a discussion regarding size without falling into this pre-fabricated notion that becoming smaller is somehow a negative consequence of some other positive gain. Leading us in this research are the Mth fruitfly, the chuckwalla, large dogs, and the completely indifferent DNA which doesn’t care about any of this.