Color change in Gecko

Several time-based and ecological factors promote speciation, although divergent selection often initiates the process of speciation, it often fails to complete it.
The Wall Gecko shows heterogeneous colour pattern, which may vary among individuals, depending on the time of day and on the habitat segregation. Nocturnal pale geckos live exclusively on walls. Diurnal dark geckos preferentially live on olive tree trunks, demonstrating a superior ability to change skin colour than the pale gecko, becoming camouflaged on the diverse substrates occupied during the day.
In our study, the nocturnal/pale/wall and diurnal/dark/trunk geckos could be considered the extremes of an ecological cline of morphological variation, on which divergent selection may be acting.
Experimental data show that diurnal and nocturnal geckos never exchange their own niches, because the predation pressure causes severe selection for background.
Genomic analysis of complete mtDNA suggests that nocturnal geckos seem to be under-balancing selection according to the narrow niche in which they live, whereas the daytime population has more opportunity in fitting into the multiple available niches, undergoing the action of positive selection.
Combining the effect of balancing selection on nocturnal geckos and disruptive selection between two sympatric populations, could lead to speciation.

Scientific publications

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