Charles Darwin proposed “natural selection” as the means by which new creatures evolve. The question then became, what does nature select? The reigning consensus is that nature selects individuals with genetic mutations, and that this eventually leads to the development of new life forms.
Few experiments, however, have tested whether or not nature could actually select a new trait even if it were developed. A new study has finally tested the concept of natural selection –and the results wouldn’t make Darwin happy.
Despite evolutionary biologists’ faith in the natural selection process, no experiment has ever demonstrated that mutations build new genetic information resulting in a new selectable trait–not even in bacteria, which can undergo tens of thousands of generations within just years.1 Leaving the question of mutations aside, a new experiment published in Nature explored whether nature, in the form of certain predators, could select lizard traits.2
The study’s scientists set up different environments for separate populations of brown anole lizards on six islands, each with a different population density. One island had birds as predators, another had snakes, and others had no predators. The scientists wanted to see whether or not predation (nature) was effective at causing (by selecting) different traits to become dominant or to even appear out of nowhere in the lizards.
The only difference that the predators made was that they ate lizards. So, there were fewer of them. On the bird-inhabited island, the lizards did spend more time clinging to the bottom of branches, but this was probably a behavior they already knew. The smaller population ended up with less diversity of body form than their forebears. The group that enjoyed the most variation in traits was the one with no predators and with the most individual lizards….
Continue Reading on www.icr.org