The turtles were incubated at temperatures that produce solely males, both sexes, and solely females. Bull, James. Spencer and Janzen found that hatchlings from mixed-sex nests were less energy efficient and grew less than their same-sex counterparts incubated in single-sex producing temperatures.
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Spencer and Janzen found that hatchlings from mixed-sex temperature-dependent sex determination in crocodilians wikipedia in Colchester were less energy efficient and grew less than their same-sex counterparts incubated in single-sex producing temperatures. Very near or at the pivotal temperature of sex determination, mixed sex ratios and more rarely intersex individuals.
Temperature pulses during the thermosensitive period are often sufficient to determine sex, but after the TSP, sex is unresponsive to temperature. Non-genetic sex determination occurs when the sex of an organism can be altered during a sensitive period of development due to external factors such as temperature, humidity, or social interactions.
The adaptive significance of TSD is currently not well understood. In future, we would like to know how an unstable environmental factor such as incubation temperature was able to establish itself as a sex determination factor.
This evolutionary model, called the Charnov-Bull model, outlines the conditions under which the evolution of environmental sex determination occurs, and scientists later applied it to vertebrates with TSD. Guillette Jr. It has been proposed  that temperature acts on genes coding for such steroidogenic enzymesand testing of homologous GSD pathways has provided a genic starting point.
Surprisingly, the sex-determining mechanisms are not the same for all houseflies -- they depend on where the insects Archived from the original on Bibcode : Sci
Between these extremes, males predominate. External link. Guillette Jr, Taisen Iguchi. It is not thought that turtles can reverse their sex after this period. An Introduction to Behavioral Endocrinology. PhD student Ryohei Yatsu said, "Reptiles can be difficult to study at times, but we were delighted to obtain such an interesting result and elucidate part of the alligator TSD mechanism.