Water Walking Lizards

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Water walking lizards described in BBC News 13 October 2009. The BBC Natural History unit have filmed two reptiles that are able to walk on water. One is a tiny gecko that is “so small it could be battered by a raindrop and risk drowning in even the smallest pool of water.” Therefore, according to the BBC “it has evolved to be essentially waterproof, which in turn allows it to walk across the surface of any puddle it encounters.” The geckos have a highly hydrophobic skin that repels water like a waterproof coat. Scientists have suggested that as the geckos became smaller, they needed to evolve a way to float, to avoid drowning when it rains. Simon Blakeney, a film producer who helped film the reptiles, explained: "Because they are so tiny, they are able to float on the surface of the water like a pondskater, so they don't break the surface tension. I've never seen anything like that to be honest.”

The other lizard that uses water as a footpath is the basilisk lizard, a rainforest dweller that lives along the edge of rivers and ponds and runs, rather than walks, on water. In fact, it runs so fast that a high speed camera was needed to show how it was done. Simon Blakeney explained: “Because they run so fast they create a bubble as their feet hit the water and then they push off from this bubble before it bursts. If they were going any slower, for example, they wouldn't stay upright, they would slip into the water and would have to swim.” Therefore, they have no option but to run. According to the BBC “The lizards need to bask in the sun to warm up each day, which leaves them vulnerable to being caught by predators, such as large birds of prey hunting from the air, or carnivores such as cats living on the jungle floor. So the lizards have evolved an extraordinary escape mechanism.” Although Simon Blakeney observed "Around 80% of the time when they are escaping from things, they don't run, they swim. So filming them running was quite a difficult thing in itself."


Editorial Comment: We wonder how many lizards drowned while they were waiting to evolve the right kind of skin, feet and behaviour. Simon Blakeney’s difficulty in getting the lizards to run on the water for his film refutes the belief they evolved their feet along with their strange behaviour as an escape mechanism. As he observed they usually swim to avoid predators – surely a much safer option than running on the water where they would be more visible and easier to catch. Furthermore, if they really wanted to escape predatory cats and birds they would be better off running into the vegetation which would totally hide them. These observations show the foolishness of trying to explain the structure and function of living things in terms of surviving environmental hazards and predation. The fact that an animal can use features it already has to survive in a hazardous, degenerate world does not explain how those features came into being. Darwinian survival of the fittest does not explain the origin of anything. (Ref. reptiles, design, locomotion)

Evidence News 17 Feb 2010