Is there scientific evidence suggesting that genetic code in the DNA can form gradually?

The genetic code contains complex and specific coded information. An example is that of the SETI project, an American research for an extraterrestrial existence in which space signals are recorded in an attempt to discover an intelligent life form. In their web site, one of the frequently asked questions is about the way they act to determine whether a signal can come from an intelligent source or if it is just a background noise. The answer is that if that signal is an encoded one, it is an unequivocal evidence that it is connected to a form of intelligence. We can ask ourselves why if we receive an encoded signal coming from the space, it means that it is linked to an intelligence, but if we speak about the thousands and thousands of cells that compose our body and about the billions of copies of genetic code they contain, it is thought that there is no intelligence behind them. Speaking about mutations, they confirm that in the species a loss of information is taking place. This means that mutations lead almost always to a loss of. So, basically the information contained in the DNA cannot be generated by chance. This is what all the laboratories and the scientific research have shown so far.