Most DNA sequences are poly-functional and so must also be poly-constrained. This means that DNA sequences have meaning on several different levels (poly-functional) and each level of meaning limits possible future change (poly-constrained).  For example, imagine a sentence which has a very specific message in its normal form but with an equally coherent message when read backwards. Now let's suppose that it also has a third message when reading every other letter, and a forth message when a simple encryption program is used to translate it. Such a message would be poly-functional and poly-constrained. We know that misspellings in a normal sentence will not normally improve the message, but at least this would be possible. However, a poly-constrained message is fascinating, in that it cannot be improved. It can only degenerate. Any misspellings which might possible improve the normal sentence from will be disruptive to the other levels of information... Trifonov (1989) has shown that probably all DNA sequences in the genome encrypt multiple codes (up to 12). ~ John Sanford



S A T O R
A R E P O
T E N E T
O P E R A
R O T A S


Like puns, palindromes, and other word puzzles, DNA contains poly-functional letters, words, and phrases. Such sequences can only arise by very careful design. Once they are created, they cannot be “mutated” to make them better. An excellent example is the painstakingly crafted poly-functional Latin phase shown above. This ancient word puzzle (dating back to 79 AD) has a translation something like, “THE SOWER NAMED AREPO HOLDS THE WORKING OF THE WHEELS.” It reads the same, four different ways: left to right, up to down, and starting at the lower right, down to up, right to left. Any single letter change in this system destroys all four messages simultaneously (all four of which happen to be the same in this example). Similarly, a simple sentence palindrome would be: ABLE WAS I ERE I SAW ELBA, which reads the same forward or backwards. Any letter change destroys both messages. A simple example of a poly-functional word would be LIVE, which backwards is EVIL. To change LIVE to HIVE might be desirable, but it turns EVIL which has meaning, to EVIH, which is meaningless. So this dual-meaning word, like the other examples above, is poly-constrained, precisely because it is poly-functional.John Sanford


No, I save on final perusal – a sure plan if no evasion.

[a spine]

Name no side in Eden, I’m mad! A maid I am, Adam mine; denied is one man.

[seen mad]

Madam in Eden, I’m Adam

[amen]

It is a challenge to find even single short words. There are some others -- can you find them? The exercise gives an appreciation for the difficulty in finding (let alone creating) overlapping code -- especially code that will yeild a meaningful/coherent/complex/aesthetic result. It also illustrates the constraints on mutations -- any letter changed will cause confusion on more than just one level.

Name no side in Eden, I’m sad! A maid I am, Adam mine; denied is one man.
Name no side in Eden, I’m mad! A maid I am, Adas mine; denied is one man.
seen sad

In the example above "mad" has an unusually high number of variations that could "work" (11/25). It could also be "bad", "cad", "dad", "fad", "had", "lad", "pad", "rad", "sad", "tad", or "wad". "Sad" is even similar to "mad", but who is "Adas"? Even if  it turns out that "sad" is an acceptable substitute, is it a better substitute? Remember: this is a best case scenario. It is easy to see how other scenarios would not fare as well -- especially when multiple mutations are introduced.

see also:
Animation  Haldane's Dilemma  Intelligent Design  Junk DNA  Mendel's Accountant  Monkeys and Shakespeare 2 3  Palindromes 2 3  Sudoku 2