What I'm saying here is just a personal reflection, that might turn to be gravely erroneous, actually I'm asking that because I didn't see it presented elsewhere.
Evolution is propelled by two directions. The first one is a process that is novel in producing genetic variation, which includes: Mutation and Migration. The second is a clearing up process, something that wash out results from the first process, and those are: Natural Selection and Genetic drift.
Natural selection is more functional in the sense that it only preserves traits that are adaptive to the environment. Genetic drift is not discriminating in that sense, so it can wash out any result of process 1 whether its harmful or beneficial.
It's clear that the primary source of evolution is the first process (i.e.; mutation and genetic migration), since the second process (i.e.; natural selection and drift) only acts on what results form it.
[Note: by primary "source" of evolution, its meant here to be what's responsible for producing the basic material upon which evolution works, since evolution is change in genetic variation over generations, then "genetic variation" is the basic material for evolution, and this is produced by mutation and migration. Natural selection and drift don't produce genetic variation, they change it by an act to decrease it, and a process that acts to decrease something, can hardly be viewed as a producer of that thing. A butcher is not the primary "source" of meat, the cow is!]
Now in principle the more we have production of genetic material the more is the chance of getting a genetic change that is useful. Of course increase in mutation rates can result in injurious traits, those would be washed out by selection and drift, however its the higher probability of having a beneficial mutation that is the primary concern here.
The male spermatogenesis in mammals supplies the impression that it is the MALE sex that is the Ore of evolution. The incomparably high cell production rate of all stages of spermatogenesis as compared to Oogenesis, tends to make one think that the chance of mutation arising in spermatogenesis is ought to be much higher than that arising in Oogenesis.
The testis seems to be the Oven in which genetic variation is baked. The rapid turnover of spermatogenesis, whereby each primary spermatocyte finally results in 4 sperms (Compared to One Ovum resulting from each primary Oogonia), that's beside the very large number of sperms produced daily, that continues for years and year. While with the Oogenesis everything really finishes at the foetal life, the remaining is just maturation steps, nothing is new as far as change of genetic material inside the Oocytes is concerned, this is the state throughout most of the female's life.
When I look at the seminiferous tubules, and see all those layers of spermatocytes leading to sperms, I tend to think that there is even some small scale natural selection, that bad mutated germline cells would die off, and only the ones with good genomes would survive all the stages of spermatogensis, and possibly the ones with beneficial mutation might have an advantage in survival in that milieu and even might have better chances of fertilizing the ovum?
Not only that, the testis seems to be more exposed to stressors inside the body and even to direct external environmental stressors, while the Ovaries lying deep inside, seem to be more protected. The Oocyte actually "selects" one sperm, so it's rule is selective rather than productive of change.
All of that makes one think that it is the male germline cells that could mediate high mutation rate in response to stressors, or even without stressors by virtue of the very high production rate of germline cells for very long periods of time. It seems that this is the real source of beneficial mutations that would ultimately drive evolution.
Four connected questions:
Is the mutation rate in male germline higher than in female germline?
If Yes, then doesn't this mean that Males are more likely the source of most beneficial genetic mutations, which is the main drive for evolution?
If 1 and 2 are true, then are we justified in inferring that "being the main source of beneficial genetic mutations" is the main purpose behind evolution of a Male sex?
Was this idea proposed before?