Harvey, Christine Janis, and John Heiser. Information about an opponent can decrease aggression in male common gobies competing for nest sites. Reptiles in which both incubation temperature and sex chromosomes interact to determine sex may represent "transitional" evolutionary states between two end points: complete GSD and complete TSD.
Andreas Svensson Authors Topi K. Notably, male exhibited aggression at a lower level in a high than low salinity, and this overall difference was mostly driven by a lower level of aggression after having encountered a female potential mate under high salinity conditions Fig.
We then gave the males several days 4. Lizard threat display handicaps endurance.
Biol Reprod 90 2 :1—11 Google Scholar. Nature Pokorna MJ, Kratochvil L What was the ancestral sex-determining mechanism in amniote vertebrates? Bull, James, and Richard Vogt. Get the most important science stories of the day, free in your inbox.
One remarkable finding is that the injection of an aromatase inhibitor into the eggs of an all-female parthenogenetic species of lizards causes the formation of males Wibbels and Crews Sexual Development. Besides simple energy depletion, aggression and fighting may also result in other negative metabolic consequences, such as elevated oxygen consumption [ 41 ] and the accumulation of lactate and other metabolic products [ 10 ].
They conjectured that disruptive selection produced by variation in the environment could result in an evolutionary transition from ESD to GSD Bull, Vogt, and Bulmer, Retrieved April 16, — via ETI. Recent studies Bergeron et al.
The gene that encodes for the male-determining factor is considered to have an optimum temperature 33 degrees C.
This model indicates that there is no genetic predisposition for the embryo of a temperature-sensitive reptile to develop as either male or female, so the early embryo does not have a "sex" until it enters the thermosensitive period of its development.
Annual Review of Genetics. Synergism between temperature and hormones has also been identified in these systems. They concluded that this differentiation in climate causes divergent selection on regulatory elements in the sex-determining network allowing for the emergence of sex chromosomes in the highlands.
Turtles of the World. Pieau and his colleagues focused on defining the TSD thermosensitive period, or the time of development during which changes in temperature can alter sexual organ growth.