From Percept Mot Skills. 2008 Dec;107(3):737-46.

Twin and family study findings indicate a substantial heritability of digit ratio (2D:4D), a putative marker for the masculinizing effects of prenatal androgen exposure. Functional polymorphisms of the X-linked androgen receptor gene, i.e., androgen sensitivity, contribute somewhat to the expression of 2D:4D in men, but otherwise the genetics of 2D:4D is unknown. This study investigated differences in 2D:4D by self-reported ABO blood type and Rhesus factor, two easily collectible genetic traits, in two samples (combined N=1273). Effects of blood groups on 2D:4D were small and not significant in all tests in both samples; however, two consistent patterns emerged across samples. Of the ABO types, AB had the lowest right-hand 2D:4D, the highest left-hand 2D:4D, and the lowest right-minus-left difference in 2D:4D, and Rhesus factor Rh- had higher left-hand 2D:4D and lower right-minus-left difference in 2D:4D than Rh+. If replicable, this may suggest genes contributing to the expression of 2D:4D reside in the vicinity of the gene loci (chromosomal locations: 9q34.2 and 1p36.11) of these blood groups or pleiotropic effects of the blood-group genes.

PubMed Link

In addition to my feverish efforts to bring www.dadamo.com back into the Information Age ---the shoemaker's kids do in fact often lack shoes--- the so-called holiday week finds your humble blogger finally mastering the intricacies of Apple's wonderful Keynote presentation software. If like me you've always used PowerPoint, Keynote is indeed a revelation.

The purpose of using presentation software is to give presentations and my upcoming lectures in Arizona are providing the necessary threat-impetus.

At the request of the Arizona Naturopathic Medical Association (AzNMA) on Saturday, January 10, 2009 I'll be doing a total of four hours of lecturing to docs and a one hour public lecture (with a half hour reserved for questions and answers) at the Doubletree Paradise Valley in Scottsdale, AZ. If you are in the Phoenix area why not plan to stop by. I can promise you that the slide/multimedia/rumination presentation may well give old Al Gore a run for the money.

Any trip to Phoenix also affords the extra benefit of seeing our good friends Paul and Laura Mittman. I'm so proud of what Paul has accomplished at Southwest College.

Found this little unused snippet from the volumes of material that was prepared for The GenoType Diet but never used. Thought it might make for interesting reading.

The high water mark of hunter-gathering is often called the Mesolithic period ('Middle Stone Age') which began around 10,000 years ago and ended with the introduction of farming. The onset of farming differed from place to place, starting early in the Near East and much later in Europe. Hunter-gatherer technology reached its apex during the Mesolithic era; fishing tackle, stone adzes, canoes and bows have all been found preserved at various sites.

Popular culture tends to depict our Stone Age ancestors as crude, simplistic animals perpetually at the point of starvation. "Solitary, poor, nasty, brutish and short" as Thomas Hobbes had put it in 1651. Nothing could be farther from the truth. Though small in number, Paleolithic hunter-gatherers worked far fewer hours and enjoyed more leisure than typical members of industrial society, and they still ate well, satisfied with very little in the material sense. The transition from hunting and gathering to agriculture was not necessarily a one way process, and evidence seems to disprove any notion that hunter-gatherers were saved from extinction by the advent of farming technology. They seem to have been familiar with farming practices when it arose, but for the longest time simply rejected it, or used it as a marginal supplement to the diet.

As these late hunter-gatherer societies evolved, they began to develop specializations such as fishing and seafood collection, harvesting nuts and fruits, or trapping small animals. They often had simple forms of representative government, based around family or clan.

Perhaps it is not coincidental that the story of the Garden of Eden in the Bible shares some of the same elements in its storyline. Some anthropologists have hypothesized that the Garden of Eden does not represent a geographical place, but rather represents cultural memory of the simpler times of hunter-gathering, when man lived off God's bounty, as opposed to being civilized and toiling at agriculture.

A large percentage of the world's cultures have stories of a Great Flood that devastated earlier civilization. This flood is sent by God or the gods as an act of divine retribution to destroy civilization. Noah and the Ark in Genesis, Matsya in the Hindu Puranas and the Epic of Gilgamesh are among the most familiar versions of these myths, all of which divide prehistory into a pre-flood or Antediluvian and a post-flood world.

Certainly there were major changes to the planetary water table at the end of the last ice age, as melting waters for the rapidly diminishing glaciers would have caused the levels of the seas and oceans to rise about 125-150 feet, deluging and destroying many prior land bridges, such as that between Alaska and Siberia, and isolating many populations. The end of the last ice age was also accompanied by the mother of all volcanic eruptions as the movement of the African plate opened a fault-line under the Mediterranean Sea, creating a string of volcanoes that still exist, such as Vesuvius and Etna. There is some geological evidence suggesting that a massive prehistoric flood occurred around 8000 years ago as the Mediterranean Sea spilled into the present day Black Sea.

William Ryan and Walter Pitman, geologists from Columbia University proposed what came be called the 'Black Sea Deluge Theory' which hypothesizes that melting of the last great glaciers caused the rising Mediterranean to finally spill over a rocky sill at the Bosporus eventually flooding 155,000 square kilometers of land. Despite some supportive findings, the theory remains an active subject of debate among archaeologists.

Although by this time agriculture had already reached the plains of central Europe, the Ryan and Pitman linked its spread with farming people displaced by the flood. It has been suggested that the memories of these displaced survivors was the source of the Great Flood Legends.

It would be nice if all the type O’s lived in one part of the world, and all the type A’s in another. However, this does not happen --much. The various blood groups are found pretty much all over the world. However they are not found in the same frequency everywhere. It was this difference in the frequency of the different blood types that gave the early blood type detectives their first insights into human individuality.

Soon after the ABO blood groups were discovered by Karl Landsteiner in the early 1900’s, scientists began to think about using them as a tool to help study the differences between populations. One of the first to begin using blood type in this manner was a husband and wife team, Ludwik and Hanka Hirszfeld. During World War I, they took blood samples from the soldiers of three continents then assembled in the area of Greece called Macedonia as “The Allied Army of the East.” In reality this army was a hodgepodge of battered contingents and survivors from various Allied nations which did little more than stay put in camp and suffer from constant epidemics. However the Hirszfelds realized that the international nature of this army presented opportunities of examining the serological properties of the blood of a large number of soldiers or civilians belonging to very different races.

They established three categories: One marked by a high percentage of subjects of blood type A and a low percentage of blood type B and which seemed to include the majority of European races (European type); A second showing on the contrary a high percentage of blood type B and a low one of blood type A, comprising Asians and Ethiopians (Asian-African type); and a last category containing approximately equal quantities of blood types A and B made up of Russians, Turks, Arabs and Jews, which they called an intermediate type.

The Hirszfelds invented an interesting and useful tool called the Hirszfeld Biochemical Index and which conveniently lets us express the ratio of blood group A to B in any population. The formula is very simple; you add up the number of blood type A and AB individuals in a population and then divide it by the number of blood type B and AB individuals. As so:

Hirszfeld Biochemical Index = [A + AB] /[B + AB]

Thus, the higher the Hirszfeld Biochemical Index of a population, the more blood type A people in that population over blood type B people in it; the lower, the more blood type B over A. The highest number in the Hirszfeld Biochemical Index (most As, least Bs) was found among the English troops (4.5); the lowest (most Bs, least As) were found in the Indian (0.5) and Vietnamese troops (0.8).

The work of the Hirszfelds would look crude in comparison to later, more sophisticated methods, and it suffers from the problems of all single-gene examinations of human diversity, that is there a no “pure races” to be identified by a single marker. But their discovery, published in 1919, did give rise to a considerable number of subsequent investigations, producing an enormous mass of documents of varying merit.

The arrival of blood typing signaled a new era in physical anthropology, since up to now the field had been limited to many of the physical measurements that I’ve previously described. Here now was a serologic, or blood marker, simple and easy to perform.

One of the first to begin using blood types as an anthropological tool was none other than William Boyd, who I’ve mentioned early in connection with the debunking of racism. In the years after the First World War, Boyd compiled the abundant blood group data coming from transfusion centers throughout the world. With his wife Lyle, during the 1930's, Boyd made a worldwide survey of the distribution of blood types. On this basis, he divided the world population into 13 geographically distinct races with different blood group genetic profiles. He also studied the blood groups of Egyptian and Amerindian mummies.

William Boyd appears to be one of those fascinating people who go on to dominate an entire area of research for a generation. It seems as if his creativity knew no bounds: I’ve already mentioned of his important work with Isaac Asimov used his work with blood types in Races and People to demolish the racist notions then commonly believed in this country during the 1950's; and here we are discussing his work on blood types and anthropology. But William Boyd accomplished much, much more than that. In the 1940’s Boyd noticed that the protein agglutinin in lima bean would agglutinate red cells of human blood type A but not those of O or B; he had in fact discovered that many of the of these blood agglutinins were actually specific to one blood type or another. With Elizabeth Shapely he coined their modern-day name; lectins which is Latin for “to pick or choose.”

Boyd wrote some excellent science fiction (under the name Boyd Ellanby) including two well-known books, 'Category Phoenix' in 1952 and 'Chain Reaction' in 1956. He also authored the Fundamentals of Immunology, one of the first Immunology textbooks for medical students.

By 1950 Boyd had determined about 20 genes for outward appearance traits that are recessive for typical Asians and/or Europeans but homozygous dominant for Africans. These recessive genes include the 6 to 8 genes for light skin color, the genes for blue eyes, gray eyes, blond hair, red hair, thin lips, straight hair, sacral spot, lack of facial hair (beards), narrow nose shape, and some others.

After the Second World War, William Boyd's baton as compiler of blood group data from around the world passed to the Englishman Arthur E. Mourant.

A native of Jersey in the Channel Islands, Mourant received a degree in geology, but as this was Depression-Era Britain, he was unable to find a job. His very strict Methodist upbringing had caused him considerable emotional unhappiness, which he hoped to resolve by becoming a psychoanalyst. To that end he decided to begin by first study medicine.

To avoid the German bombing raids on the capital, his medical school was moved from London to Cambridge, and it was here that he met Ronald Fisher, the most influential geneticist of his day. Fisher, a brilliant eccentric who we will meet again, had been working out the genetics of the new blood groups which were being discovered, and he had become fascinated by the particularly convoluted inheritance of one of them – the Rhesus blood group. Fisher found him a job at once, and the meticulous Mourant spent the rest of his working life compiling and interpreting the most detailed blood group frequency distribution maps ever produced. He never did become a psychoanalyst.

In the early 1600’s Pierre De Lancre, a French witch hunter, speculated why the Basque area seemed to harbor so many witches. He thought the problem stemmed from their great numbers in the various Jesuit missionaries, with all their evangelizing, which had affected them with demons from far-off places that they had carried back to Spain. De Lancre also thought that there early adoption of tobacco use may also be working on their minds. He held Basque women in special contempt, saying that they produced only undersized and cursed children who died.

As Mark Kurlansky recounts in The Basque History Of The World, this last accusation may have had a ring of truth to it, since Basques are renowned among anthropologists for their strikingly high percentage of individuals who have the Rhesus Negative (Rh-) blood type genotype (dd): 60% compared to an average of 16% for the rest of Europe. When a mother is Rh- and she gives birth to Rh+ children, an immune reaction can occur which gives rise to a hemolytic (“blood destroying”) anemia, and often would lead to the death of the child.

Mourant suggested that modern day Basques have other characteristics which may mark them as descendants of the late Paleolithic population of Western Europe: They share a skeletal resemblance to Cro-Magnon man and they are the only Western European people who do not speak a Indo-European language.

One way to truly screw up the truth is to subject it to public debate; since our minds want some sort of resolution, but out of inbred nicety we often want consensus as well. Problem is, as Winston Churchill so accurately pinned it, consensus is often “the sum total of everyone’s fears.”

People seem to have a love-hate relationship with genetics, or perhaps more accurately, an “awe-hate” relationship. Ask the average person what genetics means to them, and they will typically respond with a litany of dread, largely courtesy of the news media. Cloning. Stem cells. Genetically modified “Frankenfoods.” Yet ask that same person where they envision science will find the cure for cancer, or aging, or diabetes, and they will probably answer genetic research as well.

There are indeed aspects of genetics that are potentially disturbing. Consider the genetic modification of our foods. To a certain degree we are becoming one big uncontrolled experiment, as biotechnology inserts genes from one species into another, often for supercilious reasons. Do we need pesticide-resistant plants, courtesy of genetic engineering, or do we need more pesticide-free organic gardening?

It is precisely when biotechnology becomes the enabler of our existing bad habits that we lead ourselves into uncharted territory. It is also the time when the counter argument in favor of genetic modification of foods, that “nature does it all the time” rings hollow. “Nature” is a vast, living breathing mega-structure. To me Nature might more likely try to destroy pesticide manufacturers rather than re-engineer everything to be able to withstand their wares. It would certainly be easier.

In addition, we have the problem of the politically correct scientific conclusion. Scientists are human beings just like anyone else (stupider actually, if DNA pioneer James Watson were to be believed) and the pressure to conform or arrive at conclusions that are not socially distasteful (and hence not publicly fundable) is great.

But here’s what should be the goal: Take the gobs of generalized information out there, filter and analyze it, then let it guide our actions through the process of making the sort of useful decisions and actions that can produce positive change in public health. Our goal is not Eugenics (getting rid of genetic undesirables, like what the Nazis tried to do), but rather Yougenics --the science of studying yourself. As long as our fact-finding is based on the results that pertain only to you, the individual reading this blog, we will always remain on a strong, fair and firm ethical base.

I would go so far as to say that the absence of Yougenics is the main problem with nutrition as it is practiced today. All too often we read studies done on large groups of individuals and can only be left wondering if these results apply to us. Since nutrition began its meteoric rise in the public consciousness thirty years ago, we’ve been barraged with studies that have lead to sweeping conclusions and have then seen these same conclusions laid to rest, one after the other.

A lot of this is the result of nutrition being largely disease-based, a legacy of its years of discovery centered on finding the cause of deficiencies. Conventional nutritional wisdom came to define health as the absence of nutritional deficiency. Some of this is probably a ripple effect from the major developments that have taken place in the field of pharmaceutical drugs. But foods work differently than drugs. For example, we don’t make energy out of drugs; they don’t fuel or cellular processes. Foods are functional entities in our bodies, not drugs that prevent deficiencies, and our reactions to food are much more individualized than those we have to drugs.

Since nutritional science has such a rudimentary approach to food, it is not surprising that most nutrition research yields results that typically conflict with other results. And although it will eventually be yanked, no doubt kicking and screaming, into the genomic age, nutritionists still clamor for the next “one size fits all approach”, substituting one fad for another, each with its own army of disciples and detractors, the cycle to be repeated again and again.

An interesting observation on the Autism website points to the possibility that The Blood Type Diets can be helpful in managing kids with autism. We've seen some indication of this in the Clinic, and I've speculated in at least one book (Live Right For Your Type) that lectin avoidance may be the mechanism by which this occurs. Would be nice to see a good independent study on this. We can at least hope!

Many common folk also have a decidedly deterministic, perhaps fatalistic opinion of genetics. “It’s in the genes. There’s not much that you can do about it.” Nothing could be further from the truth; and although I can easily genuflect at the altar of genetics, I do not worship there. Your genes are just a reasonable plan for a particular way things can happen. Genes are just cogs in the wheel of life. They’re not here to cause disease; they are part of the structure of life.

For something so important to life, it’s quite surprising that there are so few of them; we humans have somewhere in the vicinity of 35,000 genes. Indeed when the human genome was first published scientists were incredulous to find that the number was so low (prior estimates were that there were at least 100,000.) And as if to prove that numbers aren’t everything, we humans don’t even measure up in this department as well; the average rice plant has around 40,000 genes. But then again, it’s not what you’ve got; it’s what you do with it.

It’s true, you can’t change your genes, but we are beginning to discover that Nature and Nurture do need each other. You can affect the way that your genes function. Matter of fact you do it all the time. For example, it may turn out that that dirty door knob your mother touched while she was pregnant with you may have had more influence in certain areas than all your DNA and RNA combined. As we move further into the meat and bones of this book, you will see how and why.

Genetics is typically thought of as being very complicated and difficult for the average person to understand, and this may well be true. However, the goal of this book is not to turn you into a geneticist, but rather give the advantages of conducting your life in such a way as to benefit from the knowledge of genetics.

Car showrooms can cast an interesting light on human behavior. While waiting my turn in a local dealership to buy a car, I had the chance to observe the interaction between the salesman and the young couple that he was attending to. Diligently he spouted out facts and details about the engine torque and horsepower, the suspension, and steering as the husband stood by obviously not understanding an iota of it all, but duly shaking his head and feigning great interest.

At the end of the soliloquy, our salesman of course asks if there are any questions. Not wanting to be seen as unintelligent, the young husband say no, he doesn’t have any. The young wife, on the other hand, had a burning question:

Where were the cup holders?

This simple interaction not only changed the way that I chose to write books, but changed my way of communicating in my medical practice. Most people who buy cars don’t want to repair them; they want to drive them. Yes, there is probably a very nice motor under the hood, but most intelligent people do not need convincing that there is a squirrel on a treadmill instead. For them the car is a means to an end; a way to get someplace. So, if you are willing sometimes to suspend disbelief that I am making this all up, I will repay the favor by spending the majority of our short time together teaching you how to get someplace with The Genotype Diet, rather than bludgeoning you with details that you could have easily gotten someplace else.

However, facts do make for the best stories, and I fancy myself a bit of a storyteller. However I do promise to try and keep the terminology down to a reasonable minimum, while keeping the nomenclature at the level where the names of things could at least serve as an interesting name for a pet.

“Here, Allele! Sit! Good doggy! That’s a good Allele!”

Gillian Roberts sent along this link to an interesting article about how the human genome changes with age. Sound like it is right out of The GenoType Diet if you ask me.