ABOVE: Wild water striders (Microvelia longipes) on a puddle. The animals with long third legs are the males; the others are females.
ABDERRAHMAN KHILA
Beetle horns and elk antlers are showy animal weapons that grow to outsized proportions: large beetles, for instance, have disproportionately larger horns than their smaller counterparts do. Although this phenomenon, known as hyperallometry, has been well-documented, the genetic basis for the evolution of hyperallometric traits remains incompletely understood.
Now, researchers at the Institut de Génétique Fonctionelle in Lyon, France, have discovered that the water strider Microvelia longipes’s massively exaggerated third legs, which males use to fight over access to females, are regulated by a gene called BMP11. That gene not only regulates both the size and the scaling pattern of the water strider’s weapon, but unexpectedly, is also involved in males’ fighting behavior, the researchers report in a study published today (May 11) in PLOS Biology.
“It’s ...