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 Science
Daily 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.
Links:
ScienceDaily,
Science
News Sifter
ED. COM. 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) Creation
Research.
