© Lori Lappin, the Witch of WITCHCRAFTS ARTISAN ALCHEMY®
Since the X-chromosome is related to "genetic memory", memory and cognition, I thought I'd take a look at my "cousin" X-chromosome matches at FTDNA and see if I could tease out if my active X-chromosome was a recombined mixture of genetic material from the X-chromosomes I received from both parents, or not a recombination of both parental X's (which is possible but unusual).
In a human female (who inherits two X-chromosomes, one from each parent), only one X-chromosome stays active and the other one becomes condensed and inactivated during embyogenesis. The inactivated, condensed X-chromosome is called a Barr Body.
Just looking at the ancestral surnames of my X-matches, it's clear to me that my active X-chromosome is a recombination of genetic X-material from both of my parents. All but two of my known ancestral surnames are present among my X-matches.
My ancestors having these surnames are now known to have contributed genetic material to my active X-chromosome: (maternal) Faulkner, Collins, Franklin, Turner, Grunwald; and (paternal) Taylor and Wallace. The two known ancestral surnames that I do not find among my X-matches are paternal: Sowers and Leverenz.
My X-match with the longest single block (54) of X-chromosome DNA shared with me is associated with the ancestral surname Faulkner.
So, I think it's pretty safe to think that the larger chunk of my active X-chromosome genetic material came from my maternal ancestors, with some of my active X-chromosome genetic material also being contributed by my paternal ancestors.
These are the kin-countries (where I may have relatives) of my "cousin" X-matches: England, Ireland, Scotland, Wales, Germany, Norway, Sweden, Finland, Ukraine, Netherlands, Israel, France, Switzerland, Canada, Mexico, Australia, Czechia and of course, the USA.
X-Chromosome Mediated Intelligence:
From the introduction to this book: Roderick Kaine - Smart and SeXy: Biological Differences Between Men and Women:
"The professor responded that it was a well-established fact in neuroscience that a large and inordinate number of nervous system genes map to the X chromosome. From there everything else fell into place, If the X chromosome possesses a relatively large number of recessive intelligence boosting alleles, as well as recessive intelligence lowering genes, then pseudo-dominance of X in males could easily explain the greater variability in the male intelligence distribution. To my knowledge, no other biological characteristic can explain this pattern."
So, what this means is that, to a large degree, intelligence is genetically inherited (especially boosted or diminished) from one's ancestral mothers (via the X chromosome).
WHY EVOLUTION FAVORS BOOSTING INTELLIGENCE IN A POPULATION VIA THE X CHROMOSOME - (16:22-18:10, Red Ice Interview of Roderick Kaine) "For one thing, the environment's constantly changing, so you don't know what kind of behaviors are going to be most successful ... the point is that this is a feature [of evolution], you expose the bad combinations [of mutations] to the environment so that they can be weeded out, and you expose the good combinations to the environment so that they can be enhanced. And it's beneficial [to expose the combinations to the environment] because it rapidly increases the rate of evolution., and increasing the rate of evolution is an important thing to do. It's useful because when the environment changes you want to be able to adapt to that environment quickly.. And if you have to wait for a particular new mutation [to be exposed to the environment] ... ok, if a mutation happens on the X chromosome and it's a good mutation, it is immediately exposed to natural selection [through exposure to the environment], and if it's a good one, it will propagate much faster. [on the X chromsome than it would on autosomal DNA]. If it's [the good mutation] on an autosome, and this is assuming it's recessive as well, if it's on an autosome, then it has to spread through the population, and who knows how many generations that would take, and then finally come together where there's two recessive mutations in the same individual for it to actually be exposed. So, you have a difference between ten generations [as with autosomal mutations] or more depending on the level of intermarriage versus immediate [as with X chromosome mutations] [exposure to the environment and natural selection]."
So, there may be an "autosomal genetic trigger" combined with recessive X-chromosome mutations responsible for the atypical experience of memory that I have (as well as a few others), given that this kind of memory is pretty infrequently phenotypically expressed in a population.