---Pop,here are my thoughts and reactions to that 'Big Numbers' computation
Andy
---Problems with this computation:1) It is massivly over simplified, rendering it inefficient. IF DNA didspecify exactly the length and spacial direction of all the dendrites inthe human brain, then the Base Pair chain could be as long ascalculated, also since DNA is inherited, this would mean that childrenwould show identical dendrite length and spacial orientation (or simplecombination) of their parents dendrite lenthn and spacial orientation. This is clearly NOT seem. 2) DNA sequences provide information for nucleotide sequences, which inturn produce protien and other molecules which then determine dendritegrowth. The way these molecules react with each other to producedentrite characteristics is determined by the molecules physical andchemical properties. These molecules have, because of their nucleotidechain sequences, unique shapes sizes and electron cloud density &distribution. The environment affects the way these molecules areoriented in relation to each other (spacial distance and orientation)this inturn affects how they react with each other. So two sets ofidentical protiens, produced from a the exact same piece of DNA canreact differenly because the environment may orient them in differentways to each other. So DNA does not need to carry all the informationfor all the dendrites. Just carrying th information for molecules thatmake a dendrite is enough, the microenvironment around the chemicalswill cause different dendrites to form from the same information.
To have all the information to fully predict how all the dendrites willform, we need to know every quantum mechanical detail of every moleculeinvolved and the other environmental details: light, gravity, ect. Considering that we can't know the exact position, velocity, and spin ofthe electrons around a single hydrogen atom, there is no way we can gainall the information needed to predict exact biological growth. Isuppose that if we could find the mechanics of the most sub-atomicparticles, such that we could not break it down any further, andincluded every detectable environmental variable (on this sub-atomiclevel) we could build a computational model that would exactly predicteverything from electron spin to the exact formation of biological formsin a closed system. Since the only truly closed system consists ofeverything, we would have to keep track of ever sub-atomic particle. Toconsider this even theorectically possible my a species that has troublekeeping track if it socks is thinking way to highly of the human race.
---> > "If you want to specify the connections of the human brain you need, a> 10 > billion numbers one for each cell, and then 4 numbers for each dendrite.> One > number specifies the length of the dendrite and three numbers specify> the > direction it is supposed to grow. We will assume that each neuron has> 2000 > synapses and each number requires only 11 bits of information. (this > actually is favorable to the design crowd. This eleven bits is only> enough > to represent numbers between 0 an 2048) The quantity of numbers> required to > specify the wiring diagram for the brain is > > 10 x 10^9 x 2000 x 3 = 6 x 10^13 numbers.> > I am going to rework the DNA code to encode the requisite information.> We > need to have numbers between 1 and 2000 so the triplet code won't work > because it will only represent numbers between 1 and 64. A six> nucleotide > code is required. As in the triplet code there will be some positions> not > needed. Now to represent the wiring diagram for the brain requires a> string > of DNA which is> > 6 x 6 x 10^13= 3.6 x 10^14 nucleotides long Just for the dendrites. > > The total human genome is only 3.5 x 10^9 nucleotides long. Obviously, > there is not enough information in the entire genome to encode for our> human > brain. Thus, since I believe that God did design us, the design must> lie > somewhere below this level. > > > **> The fourth number comes from this: there are 10^10 numbers needed to > specify the individual neuron from which the dendrite grows. To> represent a > number as large as 10 billion in base four (which is what DNA> is)requires a > 17 digit number. thus to ennumerate each neuron with a unique number > requires an additional 170 billion dna locations. I hope this is correct> As > with last night, I did it in a hurry. Corrections will be appreciated.>
-- Brian W. Neuschwander