Sunbathing slows evolution in island lizards: Study

Washington: A recent study has revealed that a slump in evolution in Anoles – a diminutive little tree lizard – could be linked to their affinity for basking in the sun.

Islands are considered to be hotspots for evolution in organisms, owing to the ecological opportunity presented by a simple environment with fewer competitors and predators.

However, in the case of Anoles, the ‘Island effect’ does not hold significance as the same ecological opportunity that frees island organisms from predators facilitates behavioural thermoregulation (maintaining body temperatures with physiological adjustments and behaviour).

“Mainland lizards spend most of their time hiding from predators, island lizards move around more, and are able to spend much of their day precisely shuttling between sun and shade,” said Muñoz, a researcher.

As per the study, which was published in the journal Evolution, island lizards find a shady location when it gets extremely hot, whereas, when it gets cold, they go to someplace sunny. In short, lizards shield themselves from natural weather conditions.

If lizards aren’t exposed to extreme temperatures, selection on physiology is weakened, thus resulting in slow physiological evolution, the study mentioned.

“We are discovering that organisms are the architects of their own selective environments meaning that behaviour and evolution are locked together in a delicate dance. This pas de deux tells us something important about how diversity arises in nature,” said Muñoz.