Friday, May 14, 2010


Lately astonishing amounts of insights have been coming from the study of the genome. Things that genes do and don’t do, that you might like them to do. These things are so complex that only computers make it possible to interpret them from traces of molecular code so tiny that only e.coli amplification make them accessible.

One of my recent favs is how mastodons keep their feet warm. They’re elephants, of course, which have evolved for cold weather by modifying their ear radiators. Tropical elephants have heat-carrying blood vessels for big thin ears that they flap all the time to disperse heat, but glacier elephants have dinner-plate ears with narrower blood sources. I was looking forward to information about how to keep my feet warm, but it turns out to be complicated. The first mutation is engineering like that of the ears: “Essentially the blood vessels taking the warm, oxygen-laden arterial blood down into the legs and feet pass very close to the veins carrying colder, venous blood back to be re-oxygenated. The close contact between the two types of vessels allows the arterial blood to pass its warmth on to the venous blood headed back to the heart and lungs.”

The next mutations have to do with hemoglobin molecules in the red blood cells. How these atom-by-atom changes were discovered is a whole ‘nother post. The bottom line is “. . . The mammoth hemoglobin doesn't need as much energy [heat] to offload oxygen as the Asian elephant hemoglobin does.. . . Interestingly, the mammoth DNA had two separate mutations that are different from those seen in mammals today.” Reindeer, arctic foxes, and so on. "They used a completely different way to solve the hemoglobin problem to adapt to the cold, Campbell said. ” . . . Why not humans? . . . ‘Humans could never even evolve this because if they did they would all be anemic,' Campbell said.” So back to the socks, slippers, and the foot-warmer under my computer. (Humans compensate with brains -- and paychecks.)

But “humans” is a category that has taken on new meaning since the discovery that modern humans in Europe are walking around with Neanderthal genes. Though some people have always considered “Neanderthal” to be a term of insult, the visionary comic strip “Prince Valiant,” which channels Euro history in Odyssean fashion, has for some time included “Og,” clearly a pure Neanderthal. The new scientific story line is that the Neanderthals were established in Europe when Homo Erectus (not Viagra-aided -- the term refers to the guys’ posture) made another evolutionary jump just before they emigrated out of Africa.

Exactly “how” the Neanderthals mixed with Homo Sapiens is open to speculation and, of course, everyone interprets according to their world view, writing alternative stories in their imaginations. Rape, generosity, true love, and sleep-walking all appear. But the bottom line is that Euros have maybe 2% Neanderthal in them. (About the same as the diff with chimps?) If it was the mother who was the Neanderthal, they must also have Neanderthal mitochondria, the power pack of the cells.

These lines of thought go everywhere. For instance, all the local tribal people with great-great-grandmothers who were indigenous will have their mitochondria. (It’s much more rare for a pair to have a male indigenous matched with a Euro female.) So are indigenous mitochondria an advantage or is that where the vulnerability to diabetes lives? The problem is both lack of evidence and too much evidence.

The woman who wrote “The Male Brain,” which is a roundup of genetic information, has been talking about the study of prairie voles, a little rodent which pair-bonds for life, as compared with meadow voles, which carry a slightly different gene that means promiscuity. If you put that gene into a prairie vole, it becomes promiscuous. If you put the prairie vole gene version into a meadow vole, it pair-bonds. Humans seem to have both variations. The question is how the mechanism of the molecules actually affects behavior which is often governed as much by one’s internal chemistry stream as by events out in the world.

So my next question is whether we’re talkin’ prairie Neanderthals or meadow Neanderthals. When I did some reading about them a while back, it appeared that they were gentle souls who lived in family groups in caves along rivers and strewed their dead with flowers before burying them. They had fire, made art, and probably spoke. Their bones suggest they did a lot of sitting. (I think I got that gene.)

And then the next question is whether “modern” humans could prevent war by creating a race of peaceful, bonded, “knock-out gene” people the way we create “knock-out gene” mice. Or whether we might simply “vaccinate” people against war. Or at least have a potential spouse checked for the bonding gene. (Assuming you WANT to bond and interpret that as the meaning of marriage.)

The altering of internal states that are controlled by genes is much complicated by the epigenes. It appears that the epigenes, which exist as molecules that are NOT inherited but exist as a sort of aura or “sock” or sleeve around the double-helix code, is largely able to turn genes on and off as well as modify their action. There is some evidence or opinion (which tend to interact) that environment can affect the epigenes and that they are to some extent “heritable” or contagious. One suggestion was that trauma syndromes may be rooted in the epigene, which appears to be not the keyboard of inheritance, but the piano player.

Some afflictions that are caused by an epigene that’s turned off a gene when it should be on, or vice versa, have been “cured” by finding the malfunctioning epigene and replacing it with a better version. This is, of course, near-science-fiction, more imagined than practical. Still, what if such a thing as a “make love not war” (assuming those two things are not totally entwined) gene or epigene existed and such things as “love potions” (Cree medicine) were possible?

Perhaps more to the point might be the “shape” of sexuality, bonding, territoriality, level of intensity, commitment to children, and so on. These are probably the result of interacting genes and epigenes. Same-sex attraction, disparity of need inside economically locked relationships, expression in cultural gender roles and a lot of other things might be far more the product of molecular variation than perverse defiance. Facing this might take the prudery and censorship level way down, which would be a good thing.

After all, if mastodons can evolve enough to live happily in a cold climate, why can’t Republicans evolve to live happily in a pluralistic culture? With a little help from mutations.


Anonymous said...

Hello again Mary. I am still reading your column every day, though i think i must usually be reading yesterday's column since i am usually reading before you start typing today's. It is the cold feet problem that i am writing to you about. The best thing for those cold toes is a pair of sheepskin slippers with the fleece inside. I even use wool socks inside them, and once i got that combination, i put away the hotpad that used to sit under my computer desk for chilly days. Only problem is the price of sheepskin slippers, they tend to run about $50. Mine are all holes now, but i plan to buy a sheepskin and take it to my local cobbler's shop to be made up into slippers using any moccasin pattern he happens to like. I am in Maine and i think our weather is something like yours. Warm weather is almost here, hope it is with you too.
Peggy Merrill

Alprazolam said...
This comment has been removed by a blog administrator.