Climate a major factor in lizard’s sex

LONDON - A new study has revealed that the sex of snow skink lizards is influenced by climate.

As part of the research, Ido Pen of the University of Groningen in the Netherlands and colleagues studied two clans of snow skinks, Niveoscincus greeni, living at low or high altitude in the mountains of Tasmania, Australia.

The researchers captured pregnant skinks from each clan and allowed half of each group to lie in the sun for 10 hours per day, while the others were restricted to 4 hours. When the skinks gave birth, the scientists sexed their offspring, report New Scientist.

Litters born to the lowland clan had a greater proportion of females after long days in the sun, compared to short days. In contrast, the sex ratio of the highland litters remained equal.

This suggests that temperature drives the sex of low altitude litters, while genes determine gender further up the mountain.

Pen thinks climatic pressures are behind these different systems. At low altitudes, females born early under warm conditions have more time to grow large and produce offspring, so it is advantageous for these skinks’ gender to be temperature-sensitive.

At higher altitudes, however, erratic annual temperatures mean that the timing of birth may not affect reproduction rates, so the skinks rely on genes to produce a balanced sex ratio.

The study has been published in the Nature journal. (ANI)