Even though evolutionary biologists have long recognized the size discrepancy (sexual dimorphism) between male and female animals, they have struggled for decades to solve a major paradox: How can males and females of one species be of different sizes, given that they share the same genetic blueprints dictating their development and growth?
Manduca sexta) from the time they hatched, all the way through four molts and until they pupated.
Stillwell and Davidowitz discovered that female caterpillars initiate final larval stage a bit later than the males. By the time the female caterpillars pupate, they are larger, making for larger moths when they emerge.
"Biologists think selection favors large females because they can produce more offspring," Stillwell said. link
Modern Comics #78 (Oct. 1948); © DC Comics (probably).
Pencils by Reed Crandall; Inks by Chuck Cuidera
(Is it just me or do those henchmen look too much like they should be working for The Monarch from the Venture Bros. series?)
Ref.: A developmental perspective on the evolution of sexual size dimorphism of a moth. 2010. R. C.Stillwell and G, Davidowitz. Proc. Roy. Soc. B, published online before print on March 10.