TY - JOUR
T1 - Cope’s rule and the universal scaling law of ornament complexity
AU - Raia, Pasquale
AU - Passaro, Federico
AU - Carotenuto, Francesco
AU - Maiorino, Leonardo
AU - Piras, Paolo
AU - Teresi, Luciano
AU - Meiri, Shai
AU - Itescu, Yuval
AU - Novosolov, Maria
AU - Baiano, Mattia Antonio
AU - Martínez, Ricard
AU - Fortelius, Mikael
N1 - Publisher Copyright:
© 2015 by The University of Chicago. All rights reserved.
PY - 2015/7/28
Y1 - 2015/7/28
N2 - Luxuriant, bushy antlers, bizarre crests, and huge, twisting horns and tusks are conventionally understood as products of sexual selection. This view stems from both direct observation and from the empirical finding that the size of these structures grows faster than body size (i.e., ornament size shows positive allometry).We contend that the familiar evolutionary increase in the complexity of ornaments over time in many animal clades is decoupled from ornament size evolution. Increased body size comes with extended growth. Since growth scales to the quarter power of body size, we predicted that ornament complexity should scale according to the quarter power law as well, irrespective of the role of sexual selection in the evolution and function of the ornament. To test this hypothesis, we selected three clades (ammonites, deer, and ceratopsian dinosaurs) whose species bore ornaments that differ in terms of the importance of sexual selection to their evolution.We found that the exponent of the regression of ornament complexity to body size is the same for the three groups and is statistically indistinguishable from0.25.We suggest that the evolution of ornament complexity is a by-product of Cope’s rule. We argue that although sexual selection may control size in most ornaments, it does not influence their shape.
AB - Luxuriant, bushy antlers, bizarre crests, and huge, twisting horns and tusks are conventionally understood as products of sexual selection. This view stems from both direct observation and from the empirical finding that the size of these structures grows faster than body size (i.e., ornament size shows positive allometry).We contend that the familiar evolutionary increase in the complexity of ornaments over time in many animal clades is decoupled from ornament size evolution. Increased body size comes with extended growth. Since growth scales to the quarter power of body size, we predicted that ornament complexity should scale according to the quarter power law as well, irrespective of the role of sexual selection in the evolution and function of the ornament. To test this hypothesis, we selected three clades (ammonites, deer, and ceratopsian dinosaurs) whose species bore ornaments that differ in terms of the importance of sexual selection to their evolution.We found that the exponent of the regression of ornament complexity to body size is the same for the three groups and is statistically indistinguishable from0.25.We suggest that the evolution of ornament complexity is a by-product of Cope’s rule. We argue that although sexual selection may control size in most ornaments, it does not influence their shape.
KW - Allometry
KW - Biological scaling
KW - Heterochrony
KW - Ornamental structures
KW - Sexual selection
UR - http://www.scopus.com/inward/record.url?scp=84937927733&partnerID=8YFLogxK
U2 - 10.1086/682011
DO - 10.1086/682011
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:84937927733
VL - 186
SP - 165
EP - 175
JO - American Naturalist
JF - American Naturalist
SN - 0003-0147
IS - 2
ER -