TY - CHAP
T1 - On the origin and evolutionary diversification of beetle horns
AU - Emlen, Douglas J.
AU - Lavine, Laura Corley
AU - Ewen-Campen, Ben
N1 - Publisher Copyright:
© 2007 by the national Academies of sciences. All rights reserved.
PY - 2007/12/28
Y1 - 2007/12/28
N2 - Many scarab beetles produce rigid projections from the body called horns. The exaggerated sizes of these structures and the staggering diversity of their forms have impressed biologists for centuries. Recent comparative studies using DNA sequencebased phylogenies have begun to reconstruct the historical patterns of beetle horn evolution. At the same time, developmental genetic experiments have begun to elucidate how beetle horns grow and how horn growth is modulated in response to environmental variables, such as nutrition. We bring together these two perspectives to show that they converge on very similar conclusions regarding beetle evolution. Horns do not appear to be difficult structures to gain or lose, and they can diverge both dramatically and rapidly in form. Although much of this work is still preliminary, we use available information to propose a conceptual developmental model for the major trajectories of beetle horn evolution. We illustrate putative mechanisms underlying the evolutionary origin of horns and the evolution of horn location, shape, allometry, and dimorphism.
AB - Many scarab beetles produce rigid projections from the body called horns. The exaggerated sizes of these structures and the staggering diversity of their forms have impressed biologists for centuries. Recent comparative studies using DNA sequencebased phylogenies have begun to reconstruct the historical patterns of beetle horn evolution. At the same time, developmental genetic experiments have begun to elucidate how beetle horns grow and how horn growth is modulated in response to environmental variables, such as nutrition. We bring together these two perspectives to show that they converge on very similar conclusions regarding beetle evolution. Horns do not appear to be difficult structures to gain or lose, and they can diverge both dramatically and rapidly in form. Although much of this work is still preliminary, we use available information to propose a conceptual developmental model for the major trajectories of beetle horn evolution. We illustrate putative mechanisms underlying the evolutionary origin of horns and the evolution of horn location, shape, allometry, and dimorphism.
UR - http://www.scopus.com/inward/record.url?scp=84988642921&partnerID=8YFLogxK
U2 - 10.17226/11790
DO - 10.17226/11790
M3 - Chapter
AN - SCOPUS:84988642921
SN - 030910405X
SN - 9780309104050
VL - 1
SP - 257
EP - 281
BT - Adaptation and Complex Design
PB - National Academies Press
ER -