Putting a foot in lizard evolution reported in ScienceDaily and The Scientist 23 October 2014 and Science News Sifter 27 October 2014. Anoles are small tropical lizards that live on the islands of Florida. Until 1995 a green species named Anolis carolinensis had the islands to themselves, but then a brown species named Anolis sagrei from Cuba was introduced to some of the islands. The brown lizards were larger and more robust and rapidly flourished on the forest floor, so the smaller green lizards spent more time living in the trees of the invaded islands.
Yoel Stuart of University of Texas, Austin, and colleagues studied the feet of the green lizards living on islands that had been invaded by brown lizards and compared them to lizards living on uninvaded islands. They found the ‘challenged’ green lizards which spend more time in trees, have longer toes and more lamellae – ridges and grooves on the under-surface of the toes. These larger toe-pads enable the lizards to better grip the smaller, smoother branches higher in the trees.
To confirm that the larger toe-pads were an inherited trait, rather than an individual response to living in trees they took some females about to lay eggs to their lab and let the next generation grow up in the lab. The next generation of lizards from the invaded islands had larger toe-pads than those of the uninvaded islands. The researchers concluded that this was a newly evolved trait.
As it was only a matter of 15 years, or 20 generations, since the brown lizards were introduced, the research team claim the development of larger toe-pads is an example of rapid evolution. Stuart commented: “We did predict that we’d see a change, but the degree and quickness with which they evolved was surprising”.
According to ScienceDaily this change is an example of “character displacement” where “similar species competing with each other evolve differences to take advantage of different ecological niches”. The classic example of this is considered to be Darwin’s finches, which evolved different beak shapes to take advantage of different food sources on the same islands. The lizard research team suggest that competition for food and living space is driving the evolution of toe pads. They also note that adult lizards are known to prey on the hatchlings of the other species. Stuart commented: “So it may be that if you’re a hatchling, you need to move up into the trees quickly or you’ll get eaten. Maybe if you have bigger toe pads, you’ll do that better than if you don’t”. The Science News Sifter item ends with a warning not to tell creationists about this research.
Editorial Comment: The only reason for not telling creationists about this study is so the evolutionists can maintain their belief that the lizards have evolved. The creationists know better, and are not afraid to call the evolutionists’ bluff. All the data to date shows the lizards cannot even be labelled a new species and are exactly the same species as they were before they started living in trees, so therefore, they have not evolved at all. All that has changed is the average size of an already existing characteristic.
Stuart’s explanation is probably the truth here – the lizards which already had genes for bigger toes escaped being eaten and therefore survived to pass on these bigger toe genes to the next generation, while those with smaller toes were eaten before they could reproduce. Therefore, the succeeding generations inherited the tendency for larger toes. The “bigfoot” lizards are a good example of survival of the fittest, but not of Darwinian, Dawkinsian or any other type of evolution.
The comparison with Darwin’s finches is a good one, but that is not evolution either. In their case, the Galapagos Finches, which had appropriate beak shapes for the available food on the different islands, survived to pass on their genes, while those whose beaks were less appropriate died out, and experiments done on different islands show it can happen in less than 2 decades. For more details see our report Finch Evolution in the Act. (Ref. reptiles, natural selection, ecology)
Evidence News vol. 14 No. 20
19 November 2014
Creation Research Australia