Why very little of an organism's DNA seems to serve any useful function.

So, i found a little snip of really cool C code. But, look yourself:

Newsgroups: rec.humor.funny Subject: A little C programming... Keywords: computer, smirk Date: 4 Aug 91 23:30:05 GMT

For many years molecular biologists have been mystified by the fact that very little of an organism's DNA seems to serve any useful function.

I have solved the mystery.

The reason why only 30% of human DNA performs any useful function is that the rest of it is comments.

Once we decode a typical human genome, we see that the contents begin as follows:

/\\* HUMAN_DNA.H
 \\*
 \\* Human Genome
 \\* Version 2.1
 \\*
 \\* (C) God
 \\*/

/\\* Revision history:
 \\*
 \\* 0000-00-01 00:00  1.0  Adam.
 \\* 0000-00-02 10:00  1.1  Eve.
 \\* 0000-00-03 02:11  1.2  Added penis code to male version. A bit messy --
 \\*                        will require a rewrite later on to make it neater.
 \\* 0017-03-12 03:14  1.3  Added extra sex drive to male.h; took code from
 \\*                        elephant-dna.c
 \\* 0145-10-03 16:33  1.4  Removed tail.
 \\* 1115-00-31 17:20  1.5  Shortened forearms, expanded brain case.
 \\* 2091-08-20 13:56  1.6  Opposable thumbs added to hand() routine.
 \\* 2501-04-09 14:04  1.7  Minor cosmetic improvements -- skin colour made
 \\*                        darker to match my own image.
 \\* 2909-07-12 02:21  1.8  Dentition inadequate; added extra 'wisdom' teeth.
 \\*                        Must remember to make mouth bigger to compensate.
 \\* 4501-12-31 14:18  1.9  Increase average height.
 \\* 5533-02-12 17:09  2.0  Added gay option, triggered by high population
 \\*                        density, to try and slow the overpopulation problem.
 \\* 6004-11-04 16:11  2.1  Made forefinger narrower to fit hole in centre of
 \\*                        CD.
 \\*/

/\\* Standard definitions
 \\*/

#define SEX male
#define HEIGHT 1.84
#define MASS 68
#define RACE caucasian

/\\* Include inherited traits from parent DNA files.
 \\*
 \\* Files must be pre-processed with MENDEL program to provide proper
 \\* inheritance features.
 \\*/

#include &quot;mother.h&quot;
#include &quot;father.h&quot;

#infndef FATHER
#warn(&quot;Father unknown -- guessing\n&quot;)
#include &quot;bastard.h&quot;
#endif

/\\* Set up sex-specific functions and variables
 \\*/
#include

/\\* Kludged code -- I'll re-design this lot and re-write it as a proper
 \\* library sometime soon.
 \\*/
struct genitals
   {
#ifdef MALE
   Penis \\*jt;
#endif
   /\\* G_spot \\*g;   Removed for debugging purposes \\*/
#ifdef FEMALE
   Vagina \\*p;
#endif
   }

/\\* Initialization bootstrap routine -- called before DNA duplication.
 \\* Allocates buffers and sets up protein file pointers
 \\*/
DNA \\*zygote_initialize(Sperm \\*, Ovum \\*);

/\\* MAIN INITIALIZATION CODE
 \\*
 \\* Returns structures containing pre-processed phenotypes for the organism
 \\* to display at birth.
 \\*
 \\* Will be improved later to make output less ugly.
 \\*/
Characteristic \\*lookup_phenotype(Identifier \\*i);

...and so on.

[ Note that God uses three-space tabs ]