Sexual reproduction provides the possibility to store the genetic properties of the entire human race in one single individual. Suppose you are God and you are preparing germ cells for the two humans in the ark of Noah-the-second.
E.g. suppose the alleles of hair color provide black, brown, blond and red hair. Take 4 germ cells, sperm or ova. In cell 1 is put at its proper place the allele for black hair, in cell 2 the allele for brown hair, in cell 3 blond and in cell 4 the red hair allele.
Then take the alleles of eye color, e.g. brown, green, blue and gray. Put in cell 1 the brown eye color allele, in cell 2 the green, cell 3 blue, cell 4 the gray eye color allele.
Suppose there are 6 different alleles for 6 different skin colors. Then you need 2 extra germ cells to store the 6 alleles in the way shown. The extra 2 locations for hair color and eye color are filled in with copies of already used alleles.
The number of alleles of a property cannot exceed the number of the ova in the woman then. Or the number of sperms in the man.
The prepared germ cells are put in one single individual, or in both the man and the woman. But then again, how to get all these properties out into different people again?
Spreading out again
Suppose there is a family with good property number 1. Suppose there is another family with desirable property 2. And there are families 3 and 4 with still different properties 3 and 4.
The sexual matrix mixing of genes brings fast (fastest?) properties 1, 2, 3 and 4 together within one single family.
Mental diseases like psychosis, depression and all the others seem to indicate that brain development is given a lot of freedom to deviate from the
These days we know we have genes that do not work anymore. They are there in our genome, more or less intact, but they have no function anymore. In a number of cases we found the same gene working well in animals and we were able to precisely point at the defect in the human gene why it doesn't work in us anymore. That's how nature works.
Maybe it is the same with brain parts. Maybe we have some parts in the brain that are there but inoperative, inactivated, maybe with errors too. In the course of millions of years those brain parts and the genes that steer their growth, are slowly decaying, diminishing and finally disappearing.
The reviving (repair the genes and bring them to expression) and subsequent activation of such an ancient brain part might reveal a lot about the evolution of the human brain.
But suggesting is one thing, proving it is something different. I am afraid we have to wait 100 up to 200 years until there are nanorobots with which we will be able to see what precisely is happening there in the brain and handle it properly.
See the storyline EXISTENCE, starting at page 4 of this storyline.