Sunday, March 14, 2010


I have a geek question in search of a serious answer or a fresh theory: I just read this article at Eureka! Science News about how the genome of an entire family has been sequenced to track how genetic mutations are handed on. The article states "Scientists long had estimated that each parent passes 75 gene mutations to their children." However, the actual rate of passing on was less than half of what had been estimated -- "By comparing the parents' DNA sequences to those of their children, the researchers estimated with a high degree of certainty that each parent passes 30 mutations — for a total of 60 — to their offspring."

My question is, why was the erroneous estimate so high to begin with? What were they observing that caused them to attribute a passing on of mutations at this level? And if the mutations are present but not being transmitted via our parents' DNA (which seems likely), then what IS causing the mutations?

I'm theorizing it is genetic reconfiguration that is the result of environment in early development. Cultural biological mutation, a la epigenetics. Which biological determinists and essentialists of all stripes do NOT want to admit is the case -- especially all those among us obsessed with "masculinity" as if it has authentic biological reality, instead of being a pathological cultural construct in the midst of epic fail. I am as interested in hearing "examinations of masculinity" as I am in hearing about exploring white supremacy -- i.e., it has shot its wad and we can't afford to waste any more time pretending it has value to impart. Yes, my generation looked at "femininity" which had been crammed down our throats (sometimes literally) as part of girl conditioning, but we quickly understood it was a bogus binary and instead began focusing on what was HUMAN -- and reclaiming humanity for women.

I feel this morning as if we have lost an entire generation to the rabbithole of feminist denial and a lopsided, desperate clutch at keeping the gender binary alive through the pretense of "subverting" it.

The silver lining is that money has been poured into scientific studies which hope to bolster biological determinism, and the vast majority of them (except for the tiny ones done on selected populations of adults) keep proving that culture and environment are the major factors in determining "identity". Truth will out, even if it is funded by the boys (and boy fetishists) who want to prove their definition of boy is triumphant.

NOTE: Here's another recent article from The New York Times, Human Culture Plays A Role In Natural Selection, which states that genetic adaptation to sustained cultural change "works more quickly than other selective forces, 'leading some practitioners to argue that gene-culture co-evolution could be the dominant mode of human evolution'". Yep.

[Cross-posted at Group News Blog.]


Kendra Bonnett said...

Maybe the original number was a guess or a phony science dating from a time before anyone had the actual means to count the mutations. It's happened before. Someone's original guess gets passed around long enough (like a game of telephone) and then one day it pops up as fact.

I'm glad the number is so much lower!

Maggie Jochild said...

Kenda, you could be right. Reminds me that before the human genome was sequenced, it was assumed we (humans) would have many tens of thousands more genes than we do. Many folks found our sharing about the same number of genes as much other life on earth, including flatworms, to be an ugly surprise.

Now we know that the real differentiator in DNA is not what genes are present but which ones are expressed. A lot of what was considered to be "junk" DNA is now understood to be a sort of store room of possibilities, mutations picked up along the way which can be switched on or off by that individual. And what flips the switch seems to be complicated little proteins whose number and function are exponentially more complicated than the gene itself.

I wonder why you're glad the mutation number is less. Mutations have as great a chance at being beneficial as being the stuff of nightmares. The main reason why I find epigenetics so hopeful is because it explains the apparent leaps in human development which occur too swiftly to fit into the old Darwinian natural selection model. Most of what I value most about being human vs being merely animal is the result of mutation along the way. The idea that we have created or enhanced a mechanism (culture) which can accelerate mutation is exciting and positive, once we accept that good tends to flow from good (i.e., adequate nutrition and nurturing during pregnancy and early years will produce a mutation which favors healthier future generations.)