TY - JOUR
T1 - On the origin and evolutionary diversification of beetle horns
AU - Emlen, Douglas J.
AU - Lavine, Laura Corley
AU - Ewen-Campen, Ben
PY - 2007/5/15
Y1 - 2007/5/15
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 sequence-based 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 sequence-based 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.
KW - Allometry
KW - Development
KW - Phenotypic plasticity
KW - Sexual selection
KW - Weapons
UR - http://www.scopus.com/inward/record.url?scp=34547436949&partnerID=8YFLogxK
U2 - 10.1073/pnas.0701209104
DO - 10.1073/pnas.0701209104
M3 - Review article
C2 - 17494751
AN - SCOPUS:34547436949
SN - 0027-8424
VL - 104
SP - 8661
EP - 8668
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - SUPPL. 1
ER -