Temperature-dependent sex determination
Introduction
Temperature-dependent sex determination (TSD) is a type of environmental sex determination in which the temperatures experienced during embryonic/larval development determine the sex of the offspring. It is a phenomenon observed in some reptiles, fish and insects.
Biological Mechanism
The exact mechanism of TSD is not fully understood, but it is known to involve the expression of temperature-sensitive genes during a critical period of development known as the thermosensitive period. During this period, the temperature of the environment influences the activity of enzymes that are involved in steroid hormone synthesis, which in turn influences the development of the gonads.
Evolutionary Significance
From an evolutionary perspective, TSD is thought to have advantages in certain ecological contexts. For example, in species where males and females have different ecological roles or life history strategies, TSD can allow for the production of the sex that is most beneficial in a given environmental context.
Implications for Conservation
TSD has important implications for conservation, particularly in the context of global climate change. As global temperatures rise, populations of species with TSD may become increasingly female-biased, potentially leading to population declines or even extinction.