So whereas the genetic information of a human only constitutes a small fraction of the storage capacity of a DVD disc of 4.7 Gigabyte, in order to store all the synaptic connections of a three-year-old child, around a million DVD discs are needed.
Congratulations Wolfgang - you have just proved that learning is impossible since all of the synapse connections in the brain are hard-coded in DNA!
What I have shown is this: If all the synaptic connections of a three-year-old child were hard-coded (ignoring details such as location in the brain, length of axons, synaptic plasticity, etc.), in the order of 10^16 byte = 10,000,000 Gigabyte would be needed. Yet the whole active DNA of a human is less than 10^8 byte = 0.1 Gigabyte. And this information is assumed to be responsible also for many thousand enzyme species, differentiation into more than two hundred cell types, the highly complex anatomy of the human body at all levels, human learning capacity, instinctive behaviour and even talents.
Or take the brain of a newborn instead of a three-year-old. The complexity of this brain is the main precondition for learning after birth.
As any biologist can tell you, neural development starts from a mostly random network of synaptic connections. Connections are then reinforced by learning.
An extract from your link (emphasis mine):
"Some landmarks of embryonic neural development include the birth and differentiation of neurons from stem cell precursors, the migration of immature neurons from their birthplaces in the embryo to their final positions, outgrowth of axons from neurons and guidance of the motile growth cone through the embryo towards postsynaptic partners, the generation of synapses between these axons and their postsynaptic partners, and finally the lifelong changes in synapses which are thought to underlie learning and memory.
Typically, these neurodevelopmental processes can be broadly divided into two classes: activity-independent mechanisms and activity-dependent mechanisms. Activity-independent mechanisms are generally believed to occur as hardwired processes determined by genetic programs played out within individual neurons. These include differentiation, migration and axon guidance to their initial target areas. These processes are thought of as being independent of neural activity and sensory experience. Once axons reach their target areas, activity-dependent mechanisms come into play. Neural activity and sensory experience will mediate formation of new synapses, as well as synaptic plasticity, which will be responsible for refinement of the nascent neural circuits."
Typically, these neurodevelopmental processes can be broadly divided into two classes: activity-independent mechanisms and activity-dependent mechanisms. Activity-independent mechanisms are generally believed to occur as hardwired processes determined by genetic programs played out within individual neurons. These include differentiation, migration and axon guidance to their initial target areas. These processes are thought of as being independent of neural activity and sensory experience. Once axons reach their target areas, activity-dependent mechanisms come into play. Neural activity and sensory experience will mediate formation of new synapses, as well as synaptic plasticity, which will be responsible for refinement of the nascent neural circuits."
Wikipedia on Axon guidance:
"Axon guidance (also called axon pathfinding) is a subfield of neural development concerning the process by which neurons send out axons to reach the correct targets. Axons often follow very precise paths in the nervous system, and how they manage to find their way so accurately remains a major puzzle."
One thing is sure: the information cannot come from the DNA, simply because the DNA does not contain enough information. If you try to understand the following quote from Psychons and their Evolution, you can resolve this major puzzle yourself.
The maturation of a protein from the corresponding amino acid chain can happen in the following way:
In important (evolutionarily older) sequences of the chain, amino acids become active, that is they get animated by psychons. Because of environment continuity these psychons are the ones which have built up the same protein (or the same sequence of different proteins) innumerable times. These psychons build up protein parts which can be animated as a whole by other psychons which then build up the complete protein.
So it also becomes comprehensible that RNA sequences (introns) are able to cut out themselves or that order is maintained during DNA recombination.Cheers, Wolfgang
Use as few hypotheses as possible, but not fewer!