Developmental Model Of Static Allometry In Holometabolous Insects

Biological diversity is dominated by variation in the relative sizes of different body parts. For example, we humans are characterized by our proportionally bigger brains compared to other primates, while butterflies are recognized by their proportionally larger wings compared to other insects. Nevertheless, almost nothing is known of the developmental mechanisms that regulate the relationship between organ and body size, and how they evolve.

http://www.medicalnewstoday.com/articles/107167.php