Tobias, J. T, Jones D. Other work centers on a theoretical temperature dependent sex determination in birds in Salisbury the Charnov — Bull model  predicted that selection should favour TSD over chromosome -based systems when "the developmental environment differentially influences male versus female fitness";  this theoretical model was empirically validated thirty years later  but the generality of this hypothesis in reptiles is questioned.
Proceedings of the Royal Society B. In some species, including most mammals and insects, sex is determined solely by chromosomes; in other species, sex is a matter of environmental conditions. In this case—which governs all snake species—males are the homogametic sex ZZ and females are the heterogametic sex ZW.
Other species show disproportionately high female production at both high and low temperatures, with intermediate temperatures causing mostly male development. Over the next two decades, scientists worked to test mechanisms of sex differentiation in more species and to pinpoint pivotal temperatures, which are species-specific temperature ranges in which males and females are produced in equal number.
Reproductive investment when mate quality varies: differential temperature dependent sex determination in birds in Salisbury versus reproductive compensation. The estrogen synthesis inhibitors used in the experiments mentioned above worked by blocking the aromatase enzyme, showing that experimentally low aromatase conditions yield male offspring.
As ofsixty-five of seventy-nine tested species of turtles were found to exhibit TSD. Underground nesting in the megapodes.
In birds, males often have a more colourful appearance and may have features like the long tail temperature dependent sex determination in birds in Salisbury male peacocks that would seem to put the organism at a disadvantage e.
A low incubation temperature during the development of this lizard's egg reverses some genotypic females XX into "phenotypic" males—so that they have only functioning male reproductive organs. Sex Chromosomes and Sex-Linked Genes.
Wikimedia Commons Wikiquote. NIH, 3. This thermosensitive period occurs after the egg has been laid, so sex determination in these reptiles is at the mercy of the ambient conditions affecting egg clutches in nests. Molecular Cell Biology Fourth ed.
New Jersey: Prentice Hall, Pre-hatching exposure to water mold reduces size at metamorphosis in the moor frog. Therein it differentiates into a minute 1—3-mm-long male that is essentially a sperm-producing symbiont of the female see Figure 3.
Fertility and Sterility. After Crain and more New Jersey: Pearson Education,