1. Alternative Strategies: The Evolution of Switch Points
Derek A. Roff 
Current Biology 
Volume 21, Issue 8, Pages R285-R287 (April 2011)
DOI: /j.cub
Copyright © 2011 Elsevier Ltd Terms and Conditions

2. Figure 1 Wing dimorphism in the sand cricket.
Wing dimorphism is an example of variation generated by a threshold trait. The long-winged, flight capable morph on the left possesses both large, functional wings and the associated flight musculature and flight fuels, whereas the flightless, short-wing morph on the right lacks the flight musculature and invests more in reproduction rather than flight fuels.
Current Biology  , R285-R287DOI: ( /j.cub )
Copyright © 2011 Elsevier Ltd Terms and Conditions