TY - JOUR
T1 - Allometric analysis of sexual dimorphism and morphological variation in two chromosome races of the Sceloporus grammicus complex (Squamata: Phrynosomatidae) from Mexico
AU - Lozano, Abraham
AU - Sites, Jack W.
AU - Ramírez-Bautista, Aurelio
AU - Marshall, Jonathon C.
AU - Pavón, Numa P.
AU - Cruz-Elizalde, Raciel
N1 - Publisher Copyright:
© 2023 Senckenbergische Naturforschende Gesellschaft. All rights reserved.
PY - 2023
Y1 - 2023
N2 - Sexual dimorphism is a widespread feature in the Animal Kingdom. In lizards of the Sceloporus grammicus complex, studies of sexual dimorphism that analyze the allometric trajectories of body traits remain unexplored. Here we investigate sexual dimorphism in key phenotypic traits, including body size (snout-vent length, SVL) as well as head length (HL), head width (HW), and forearm length (FL). We use an allometric approach to detect differences in scale relationships among body parts in the S. grammicus complex in Mexico. We focus on two chromosomal races within this complex, F5 (2n = 34) and FM2 (2n = 46). In the complex, we found that males are larger than females in all morphological variables, and this pattern was confirmed in both races. We determined negative allometric trajectories (SVL vs. HL and HW), isometry (SVL vs. FL) and intersexual differences in the slopes of the SVL vs. HL and HW; the males showed steeper slopes. Thus, the growth of the head is more pronounced in males than females. Additionally, we found between-race differences in these trajectories (SVL vs. FL) and in all morphological variables (F5 lizards are larger than those of the FM2 race), which correlate with their chromosomal divergence. We discuss biological implications of our findings in relation to sexual selection and natural selection.
AB - Sexual dimorphism is a widespread feature in the Animal Kingdom. In lizards of the Sceloporus grammicus complex, studies of sexual dimorphism that analyze the allometric trajectories of body traits remain unexplored. Here we investigate sexual dimorphism in key phenotypic traits, including body size (snout-vent length, SVL) as well as head length (HL), head width (HW), and forearm length (FL). We use an allometric approach to detect differences in scale relationships among body parts in the S. grammicus complex in Mexico. We focus on two chromosomal races within this complex, F5 (2n = 34) and FM2 (2n = 46). In the complex, we found that males are larger than females in all morphological variables, and this pattern was confirmed in both races. We determined negative allometric trajectories (SVL vs. HL and HW), isometry (SVL vs. FL) and intersexual differences in the slopes of the SVL vs. HL and HW; the males showed steeper slopes. Thus, the growth of the head is more pronounced in males than females. Additionally, we found between-race differences in these trajectories (SVL vs. FL) and in all morphological variables (F5 lizards are larger than those of the FM2 race), which correlate with their chromosomal divergence. We discuss biological implications of our findings in relation to sexual selection and natural selection.
KW - Lizards
KW - morphology
KW - natural selection
KW - sexual selection
KW - shape
KW - size
UR - http://www.scopus.com/inward/record.url?scp=85148293416&partnerID=8YFLogxK
U2 - 10.3897/vz.73.e94004
DO - 10.3897/vz.73.e94004
M3 - Artículo
SN - 1864-5755
VL - 73
SP - 23
EP - 34
JO - Vertebrate Zoology
JF - Vertebrate Zoology
ER -