Bacteria have way more DNA than we have. There appears to be no correlation between the complexity of an organism and the length of its DNA. The British biologist and philosopher Rupert Sheldrake argues that DNA does not encode information. It's more like a radio tuner. Human genes are *slightly* different from chimpanzee genes, but this difference is perfectly adequate, because, by analogy, two radio stations could be right next to each other while still playing quite different music. DNA distinguishes species from each other, and within species distinguishes individuals. You might have a gene that makes you near-sighted or gives you brown eyes. Does that mean DNA "encodes" the "blueprint" of your eyes? That's a bit of a leap. DNA is like when you go buy a car and you can get certain features, like a particular color or power steering or a CD player. The other function of DNA, according to Sheldrake, is to provide a template for chains of amino acids. After that, the amino acids are on their own. DNA has no effect on their ability to fold into protein. So everything in the body, starting with protein, functions independently of the actions of DNA.
Sheldrake argues persuasively that organic structures are influenced by their own activities in the past. In other words, what's driving it all is biological memory. Human DNA tunes the body into the memory of *human* ontogenesis (formation of the body). The more humans there have been, and the longer we've been around, the stronger the memory. It's a shared, composite memory, with differences in DNA serving to individuate us. Once ontogenesis gets going, every level of structure is guided into place by the memory of that particular level, on up to the whole body. DNA just distorts some of the effects.
Ted