"Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteers be at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe."
From this rather dated article:
If You Can Raed Tihs, You Msut Be Raelly Smrat | Fox News
Written language (as well as spoken language, but it’s much harder to demonstrate) can suffer a great many mutations without any loss of information. This is primarily due to its being highly redundant. This redundancy makes it very robust in the face of errors which is very important since language is a basic form of communication and can be essential for survival.
A species genome is also essential for survival and must therefore be very robust in the face of all sorts of insults that result in changes. One form of this robustness is an elaborate (but mechanistically simple) edit and repair process. But for a second form it would be surprising if genomes are not highly redundant and able to incur extensive changes without compromising the viability of the organism/species.
So maybe it’s not so surprising that random sequences of bases can yield useful dna since, in a real sense, the original dna is highly random to start with and only a few key elements have to be maintained. This is shown in the molecular homology maps of proteins, which compare the amino acid sequences for proteins from different species that perform the same function. These sequences can vary widely and even be of different lengths with only a few short regions (that interact with the ligands the protein contacts) being very similar.
This robustness through redundancy also applies to our bodies as a whole and well engineered products. (As an example, the solid-state-drive of the computer I’m typing this on has 20% spare memory).