Testosterone stress does not increase asymmetry of a hormonally mediated sexual ornament in a lizard

被引:14
作者
Veiga, JP
Salvador, A
Martin, J
Lopez, P
机构
[1] Depto. de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, C.S.I.C., E-28006 Madrid
关键词
fluctuating asymmetry; ornament size; Psammodromus algirus; testosterone;
D O I
10.1007/s002650050376
中图分类号
B84 [心理学]; C [社会科学总论]; Q98 [人类学];
学科分类号
03 ; 0303 ; 030303 ; 04 ; 0402 ;
摘要
The theory that fluctuating asymmetry is sensitive to both environmental and genetic stress is gaining acceptance among evolutionary biologists. Most empirical work has focused on ornamental traits on the assumption that they are more susceptible to stress. Integumentary coloration is a common ornament in nature, and frequently has a hormonal basis. Earlier studies in the lizard Psammodromus algirus indicate that testosterone induces the development of head nuptial coloration in large males and, at the same time, produces an increase of the ectoparasite load and higher mortality. Hence, the manipulation of testosterone levels may be a way to increase ornament expression and simultaneously create conditions that may make symmetrical development difficult. This positive covariation between character size and symmetry is opposite to that expected in theory for sexually selected traits, so the predicted elevation of asymmetry due to the treatment cannot be confounded by any intrinsic association between symmetry and character size. We firstly consider the effect that testosterone supplementation has on two variables that reflect the symmetry of bilateral throat nuptial coloration in large P. algirus males. Also, we examine whether ornament symmetry is positively associated with reproductive success, a prediction of theory of sexually selected symmetry. Testosterone treatment did not increase the fluctuating asymmetry of throat coloration. Size asymmetry increased with character size in individuals with a fragmented colour pattern, but changed suddenly to a highly symmetric pattern in individuals with non-fragmented coloration. Mirror asymmetry decreased steadily with character size. These results suggest that the development of coloration on both sides of the throat midline follows a random pattern. Asymmetry did not correlate with variables that estimated reproductive success, suggesting that asymmetry is not affected by physiological stress and that this trait is not a sexually selected signal in P. algirus.
引用
收藏
页码:171 / 176
页数:6
相关论文
共 40 条
[1]   Sexual selection [J].
Andersson, M ;
Iwasa, Y .
TRENDS IN ECOLOGY & EVOLUTION, 1996, 11 (02) :53-58
[2]  
Andersson Malte, 1994
[3]  
[Anonymous], [No title captured]
[4]   FEMALE CHOICE IN A FERAL GUPPY POPULATION - ARE THERE MULTIPLE CUES [J].
BROOKS, R ;
CAITHNESS, N .
ANIMAL BEHAVIOUR, 1995, 50 :301-307
[5]   INDUCTION OF ORANGE HEAD COLORATION AND ACTIVATION OF COURTSHIP AND AGGRESSION BY TESTOSTERONE IN THE MALE BROAD-HEADED SKINK (EUMECES-LATICEPS) [J].
COOPER, WE ;
MENDONCA, MT ;
VITT, LJ .
JOURNAL OF HERPETOLOGY, 1987, 21 (02) :96-101
[6]  
Cooper WE, 1992, BIOL REPTILIA HORMON, V18, P298
[7]  
Darwin G., 1871, P423
[8]   EFFECTS OF STEROID-HORMONE INTERACTION ON ACTIVITY AND HOME-RANGE SIZE OF MALE LIZARDS [J].
DENARDO, DF ;
SINERVO, B .
HORMONES AND BEHAVIOR, 1994, 28 (03) :273-287
[9]   BREEDING COLORATION, MATING OPPORTUNITIES, ACTIVITY, AND SURVIVAL IN THE LACERTID LIZARD PSAMMODROMUS-ALGIRUS [J].
DIAZ, JA .
CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE, 1993, 71 (06) :1104-1110
[10]   REGIONAL DISTRIBUTION OF A MEDITERRANEAN LIZARD - INFLUENCE OF HABITAT CUES AND PREY ABUNDANCE [J].
DIAZ, JA ;
CARRASCAL, LM .
JOURNAL OF BIOGEOGRAPHY, 1991, 18 (03) :291-297