Chromatin binding runs in families:
The word chromatin has a highly technical meaning which I interpret to mean the chromosomes you see under a microscope, although they are not usually so visible. The function of the DNA in the chromosome is to carry information that is transcribed onto a form of RNA that then moves out into the cell and is used there by the cell machinery to make proteins. For this to happen, chemicals called transcription factors must bind to the chromosomes. It turns out that this binding varies with structural variations in the chromosomes. And this, it is thought, may account for the fact that a gene can be expressed to different degrees in different individuals. This is one of the “epigenetic” pheromones – inheritable charactarisics that are not governed by classical Mendelian genes.
The work is described in Variations in Transcription Factor Binding Among Humans Maya Kasowski et al. SCIENCE vol. 328 no. 5975 April 9, 2010 page 232. This effect of chromatin structure on gene expression appears to be inheritable.
So there are a number of inherited things that make us different from each other as individuals. Genes can vary. Chromatin structure varies, affecting how the gene is expressed. And there are other epigenetic effects. That means processes like hooking an extra carbon atoms (with its complement of attendant hydrogen atoms together called a methyl group) onto the outside of DNA. Or sometimes it is an ethyl group, which would be two carbon atoms. The added group can alter the way the gene is expressed. The field of epigenetics is quite technical, but it does seem to permit a rapid inheritable change in gene function over one or a very few generations. DNA mutations apparently take a lot longer, and so - one might expect - would changes in chromatin structure. But that proves not to be the case. (Epigenetics as a Unifying Principle in the Aetiology of Complex Traits and Diseases Arturas Petronis of the Krembil Family Epigenetics Laboratory, Centre for Addiction and Mental Health, 2050 College Street, Toronto Ontario MST 1RB, Canada NATURE vol. 721 no. 7299 June 10, 2010 page 721)
What is more, since epigenetic signals are to a degree inheritable, and since they may be implicated in memory (Brain Function and Chromatin Plasticity Catherine Dulac, NATURE vol. 721 no. 7299 June 10, 2010 page 728) that leads us to a rather unnerving speculation. Can one inherit memory?
Suddenly reality seems squishy underneath. The idea is not new. The New England Transcendentalists thought perhaps babies came from heaven and having been there so recently might hold memories of such a place. New England born Edgar Allan Poe took the opposite view and thought those near death might gain insights from heaven. New England horror writer thought those who were about to die might know something of the afterlife. The hypothesis emerges that New England is a very strange place.
As a very young child I was as convinced that I had memories from before birth, things seen though my parents’ eyes, as I am convinced now that I did not. Of course for any such thing to be true there would have to be a way for epigenetic information from elsewhere to find its way to the gametes. Odd as it should seem, there is a name for that. The elements are called “pangenes.” These were thought to carry signals from the body to be encoded onto the egg and sperm. Mirth is pretty much the only use for pangenes these days, but we might be getting back there. Among people who believed in it or at least took it seriously was Charles Darwin. There is no such mechanism known, but epigenetics is just getting started. One can only hope that further study will eliminate the possibility. At all events, any such revenant memory would be uninterpretable. Even my own perinatal memories were poorly organized. They seemed mythic, charged with emotional intensity but not impelling any organized rational response. Remember, I was very young. Do not expect a lucid narrative from very early life, far less if it exists from any carryover from previous life. At all events they almost surely do not exist. But the existence of inheritable non-genetic traits seems to be fact.
It is all very intriguing and more than a little baffling. But somewhere in there is the source of the kin recognition system that produces the relationship between population size and fertility that has been seen.
The machine says there have been 4,031 different visitors since we got started. Yesterday it said 4.052, which means that either the machine is acting up again or we are being visited by negative people.