## Evolution can progress relatively quickly and similar features of various organisms can develop independently of each other

We cannot consider evolution as a purely random process. The occurrence of mutations is random, but the selection in favour of a certain variant is always determined by something. An example is the work of the prominent American evolutionary biologist Jonathan Losos, who devoted most of his scientific career to the study of the ecology and evolution of lizards of the genus Anoles. About 400 species of these lizards live in South and Central America, while about 200 live on islands in the Caribbean Sea. Such islands represent huge "test tubes" for terrestrial animals, where it is possible to independently observe how a given species develop under harsh conditions. The islands in the Caribbean Sea offer different ecological environments, different types of predators, and competitors, and are often hit by tropical storms. In the 1980s, Losos and his colleague conducted an experiment in which they brought lizards to islands where no lizards had previously lived and observed what changes they would undergo. They observed the signs of the environment that the lizards inhabit (tops of trees, grass or the ground, etc.), they also observed the joints of the legs, length of the digits and the colour of the chin lobe of the lizards. After approximately 10 years, they evaluated how the lizards performed in this new environment. They found that all the lizards chose a certain type of environment for their new life, while lizards living in the same conditions on different islands independently developed similar behavioural traits. For example, lizards living on the ground have longer limbs that allow them to escape from predators faster, while lizards living in treetops have shorter limbs to be more agile when moving. In addition, the lizards living in the treetops have longer last digits (toes) so that they can better hold on to the branches. Lizards on islands where hurricanes are more frequent also have longer toe joints. As for the chin lobe, which they use as a warning against enemies, but also to attract attention during mating, the lizards living in darker environments had a paler chin lobe, so that the environment would have a stronger contrast. On the other hand, lizards living in sunny places had their chin lobes more prominently coloured. The experiments by Losos showed that evolution can be relatively fast if the selection pressure is very strong. Moreover, if the selection conditions are the same, organisms can independently acquire the same characteristics (we call this phenomenon convergent evolution).