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AMONG‐FAMILY VARIATION FOR ENVIRONMENTAL SEX DETERMINATION IN REPTILES
Author(s) -
Rhen Turk,
Lang Jeffrey W.
Publication year - 1998
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.1998.tb02034.x
Subject(s) - chelydra , alligator , turtle (robot) , painted turtle , biology , sex ratio , american alligator , zoology , variation (astronomy) , ecology , demography , population , physics , sociology , astrophysics
Unlike birds and mammals, in many reptiles the temperature experienced by a developing embryo determines its gonadal sex. To understand how temperature‐dependent sex determination (TSD) evolves, we must first determine the nature of genetic variation for sex ratio. Here, we analyze among‐family variation for sex ratio in three TSD species: the American alligator ( Alligator mississipiensis ), the common snapping turtle ( Chelydra serpentina ) and the painted turtle ( Chrysemys picta ). Significant family effects and significant temperature effects were detected in all three species. In addition, family‐by‐temperature interactions were evident in the alligator and the snapping turtle, but not in the painted turtle. Overall, the among‐family variation detected in this study indicates potential for sex‐ratio evolution in at least three reptiles with TSD. Consequently, climate change scenarios that are posited on the presumption that sex‐ratio evolution in TSD reptiles is genetically constrained may require reevaluation.