February, 2010


24
Feb 10

Yes There Are Monogamous Amphibians

Frogs, salamanders, and other amphibians aren’t known as faithful lovers. They mate, then they scram. But researchers have now identified one species of poisonous Peruvian frog—Ranitomeya imitator—that has given monogamy a shot, the first amphibian known to do so. What’s more, the frogs seem Frogs, salamanders, and other amphibians aren’t known as faithful lovers. They mate, then they scram. But researchers have now identified one species of poisonous Peruvian frog—Ranitomeya imitator—that has given monogamy a shot, the first amphibian known to do so. What’s more, the frogs seem to be doing it for the kids: Limited resources keep them close to their offspring-and to each other-a condition that may have influenced the evolution of parenting strategies in other species as well.
to be doing it for the kids: Limited resources keep them close to their offspring-and to each other-a condition that may have influenced the evolution of parenting strategies in other species as well.

On the surface, R. imitator and its relative R. variabilis, are quite similar. They look alike, sharing the same poisonous skin, ostentatious coloring, and compact, 20-millimeter-long body. They mate alike, with a loud and elaborate courtship. And, at least at first, they treat their young alike: After the female deposits her eggs on a leaf, the male fertilizes them, and, when the eggs hatch, he coaxes each tadpole onto his back and ferries it to a nearby pool.

But then the two species’ approaches to parenting diverge. R. variabilis moms hit the road immediately after mating, and while dads guard the territory around their young, they largely leave tadpoles to fend for themselves. In contrast, parent R. imitator frogs coddle their young. Once tadpoles are safe in individual leaf-pools, “the work has just started,” says Kyle Summers, an evolutionary ecologist at EastCarolinaUniversity in Greenville, North Carolina. About once a week for the next few months, the R. imitator dad calls the mother back to the pool so she can lay a nutritious egg for the tadpoles to eat.

(Link)


23
Feb 10

General Intelligence Located In The Brain

There’s an interesting paper called "Distributed neural system for general intelligence revealed by lesion mapping". (It’s open access, so anyone can read it online.)

The paper claims to have found the regions of the brain associated with general intelligence.

Here’s an excepts from ScienceDaily….

A collaborative team of neuroscientists at the California Institute of Technology (Caltech), the University of Iowa, the University of Southern California (USC), and the Autonomous University of Madrid have mapped the brain structures that affect general intelligence.

The study, to be published the week of February 22 [2010] in the early edition of the Proceedings of the National Academy of Sciences, adds new insight to a highly controversial question: What is intelligence, and how can we measure it?

[The Scientists] examine[d] a uniquely large data set of 241 brain-lesion patients who all had taken IQ tests. The researchers mapped the location of each patient’s lesion in their brains, and correlated that with each patient’s IQ score to produce a map of the brain regions that influence intelligence.
[...]
The researchers found that, rather than residing in a single structure, general intelligence is determined by a network of regions across both sides of the brain.

“One of the main findings that really struck us was that there was a distributed system here. Several brain regions, and the connections between them, were what was most important to general intelligence,” explains Gläscher.

“It might have turned out that general intelligence doesn’t depend on specific brain areas at all, and just has to do with how the whole brain functions,” adds Adolphs. “But that’s not what we found. In fact, the particular regions and connections we found are quite in line with an existing theory about intelligence called the ‘parieto-frontal integration theory.’ It says that general intelligence depends on the brain’s ability to integrate — to pull together — several different kinds of processing, such as working memory.”

(Emphasis mine.)

Or in the words of the authors of the paper….

Distributed neural system for general intelligence revealed by lesion mapping

J. Gläschera, D. Rudraufc, R. Colome, L. K. Paula, D. Tranelc, H. Damasiof, and R. Adolphsa

Abstract

General intelligence (g) captures the performance variance shared across cognitive tasks and correlates with real-world success. Yet it remains debated whether g reflects the combined performance of brain systems involved in these tasks or draws on specialized systems mediating their interactions. Here we investigated the neural substrates of g in 241 patients with focal brain damage using voxel-based lesion–symptom mapping. A hierarchical factor analysis across multiple cognitive tasks was used to derive a robust measure of g. Statistically significant associations were found between g and damage to a remarkably circumscribed albeit distributed network in frontal and parietal cortex, critically including white matter association tracts and frontopolar cortex. We suggest that general intelligence draws on connections between regions that integrate verbal, visuospatial, working memory, and executive processes.


21
Feb 10

Al Gore Bought $4M Condo In Area He Claimed Will Be Underwater Due To AGW

Al Gore bought a $4M condo feet from ocean in Fisherman’s Wharf, San Fransisco, a city he had explicitly warned about in An Inconvenient Truth. I heard about this from a couple people, but I finally found a source (from December 8th, 2009). Here’s an excerpt.

With the nations gathering in Copenhagen for their Climate Change Conference, I’m going to perform a little science experiment.

It’s based on what Al Gore said in his “Inconvenient Truth”: The polar icecaps will melt sending 20-plus-foot flood waves into coastal cities worldwide. [...]

“Did you know that he bought a property in San Francisco near Fisherman’s Wharf, only four feet from the ocean? I would say that if he believed that the seas were going to rise 23 feet, he would not have invested a great deal of money in such a property.”

Good point.

(Link)

Of course, none of this proves or disproves whether there is AGW. But only shows another example of the political and religious drama that is Greenism.


21
Feb 10

Midday Naps Make You Smarter?

If you see a student dozing in the library or a co-worker catching 40 winks in her cubicle, don’t roll your eyes. New research from the University of California, Berkeley, shows that an hour’s nap can dramatically boost and restore your brain power. Indeed, the findings suggest that a biphasic sleep schedule not only refreshes the mind, but can make you smarter.

Conversely, the more hours we spend awake, the more sluggish our minds become, according to the findings. The results support previous data from the same research team that pulling an all-nighter — a common practice at college during midterms and finals — decreases the ability to cram in new facts by nearly 40 percent, due to a shutdown of brain regions during sleep deprivation.

(Link)


21
Feb 10

Don’t Wake The Baby, So That He Can Learn And Retain New Information

Anyone who grew up in a large family likely remembers hearing “Don’t wake the baby.” While it reinforces the message to older kids to keep it down, research shows that sleep also is an important part of how infants learn more about their new world.

Rebecca Gomez, Richard Bootzin and Lynn Nadel in the psychology department at the University of Arizona in Tucson found that babies who are able to get in a little daytime nap are more likely to exhibit an advanced level of learning known as abstraction.

(Emphasis mine.)

(Link)


21
Feb 10

Dog Morality

Seems that dogs, wolves, and coyotes posses morality, and that morality is similar to human morality.

Looking for the roots of human morality in the animal kingdom? Focus on canines, who know how to play fair
[...]
Every dog owner knows a pooch can learn the house rules—and when she breaks one, her subsequent groveling is usually ingratiating enough to ensure quick forgiveness. But few people have stopped to ask why dogs have such a keen sense of right and wrong. Chimpanzees and other nonhuman primates regularly make the news when researchers, logically looking to our closest relatives for traits similar to our own, uncover evidence of their instinct for fairness. But our work has suggested that wild canine societies may be even better analogues for early hominid groups—and when we study dogs, wolves and coyotes, we discover behaviors that hint at the roots of human morality.

Morality, as we define it in our book Wild Justice, is a suite of interrelated other-regarding behaviors that cultivate and regulate social interactions. These behaviors, including altruism, tolerance, forgiveness, reciprocity and fairness, are readily evident in the egalitarian way wolves and coyotes play with one another. Canids (animals in the dog family) follow a strict code of conduct when they play, which teaches pups the rules of social engagement that allow their societies to succeed. Play also builds trusting relationships among pack members, which enables divisions of labor, dominance hierarchies and cooperation in hunting, raising young, and defending food and territory. Because this social organization closely resembles that of early humans (as anthropologists and other experts believe it existed), studying canid play may offer a glimpse of the moral code that allowed our ancestral societies to grow and flourish.

(Link)


21
Feb 10

Andrew Joseph Stack

You’re probably already heard of the late Andrew Joseph Stack who flew a plane into a building in Austin, Texas housing IRS offices.

Copies of what appears to be Andrew’s length diatribe have have been replicated all across the Internet. I’ve replicated it below too, for those interested in reading it.

If you’re reading this, you’re no doubt asking yourself, “Why did this have to happen?” The simple truth is that it is complicated and has been coming for a long time. The writing process, started many months ago, was intended to be therapy in the face of the looming realization that there isn’t enough therapy in the world that can fix what is really broken. Needless to say, this rant could fill volumes with example after example if I would let it. I find the process of writing it frustrating, tedious, and probably pointless… especially given my gross inability to gracefully articulate my thoughts in light of the storm raging in my head. Exactly what is therapeutic about that I’m not sure, but desperate times call for desperate measures.

We are all taught as children that without laws there would be no society, only anarchy. Sadly, starting at early ages we in this country have been brainwashed to believe that, in return for our dedication and service, our government stands for justice for all. We are further brainwashed to believe that there is freedom in this place, and that we should be ready to lay our lives down for the noble principals represented by its founding fathers. Remember? One of these was “no taxation without representation”. I have spent the total years of my adulthood unlearning that crap from only a few years of my childhood. These days anyone who really stands up for that principal is promptly labeled a “crackpot”, traitor and worse.

While very few working people would say they haven’t had their fair share of taxes (as can I), in my lifetime I can say with a great degree of certainty that there has never been a politician cast a vote on any matter with the likes of me or my interests in mind. Nor, for that matter, are they the least bit interested in me or anything I have to say.

Why is it that a handful of thugs and plunderers can commit unthinkable atrocities (and in the case of the GM executives, for scores of years) and when it’s time for their gravy train to crash under the weight of their gluttony and overwhelming stupidity, the force of the full federal government has no difficulty coming to their aid within days if not hours? Yet at the same time, the joke we call the American medical system, including the drug and insurance companies, are murdering tens of thousands of people a year and stealing from the corpses and victims they cripple, and this country’s leaders don’t see this as important as bailing out a few of their vile, rich cronies. Yet, the political “representatives” (thieves, liars, and self-serving scumbags is far more accurate) have endless time to sit around for year after year and debate the state of the “terrible health care problem”. It’s clear they see no crisis as long as the dead people don’t get in the way of their corporate profits rolling in.

And justice? You’ve got to be kidding!

How can any rational individual explain that white elephant conundrum in the middle of our tax system and, indeed, our entire legal system? Here we have a system that is, by far, too complicated for the brightest of the master scholars to understand. Yet, it mercilessly “holds accountable” its victims, claiming that they’re responsible for fully complying with laws not even the experts understand. The law “requires” a signature on the bottom of a tax filing; yet no one can say truthfully that they understand what they are signing; if that’s not “duress” than what is. If this is not the measure of a totalitarian regime, nothing is.

How did I get here?

My introduction to the real American nightmare starts back in the early ‘80s. Unfortunately after more than 16 years of school, somewhere along the line I picked up the absurd, pompous notion that I could read and understand plain English. Some friends introduced me to a group of people who were having ‘tax code’ readings and discussions. In particular, zeroed in on a section relating to the wonderful “exemptions” that make institutions like the vulgar, corrupt Catholic Church so incredibly wealthy. We carefully studied the law (with the help of some of the “best”, high-paid, experienced tax lawyers in the business), and then began to do exactly what the “big boys” were doing (except that we weren’t steeling from our congregation or lying to the government about our massive profits in the name of God). We took a great deal of care to make it all visible, following all of the rules, exactly the way the law said it was to be done.

The intent of this exercise and our efforts was to bring about a much-needed re-evaluation of the laws that allow the monsters of organized religion to make such a mockery of people who earn an honest living. However, this is where I learned that there are two “interpretations” for every law; one for the very rich, and one for the rest of us… Oh, and the monsters are the very ones making and enforcing the laws; the inquisition is still alive and well today in this country.

That little lesson in patriotism cost me $40,000+, 10 years of my life, and set my retirement plans back to 0. It made me realize for the first time that I live in a country with an ideology that is based on a total and complete lie. It also made me realize, not only how naive I had been, but also the incredible stupidity of the American public; that they buy, hook, line, and sinker, the crap about their “freedom”… and that they continue to do so with eyes closed in the face of overwhelming evidence and all that keeps happening in front of them.

Before even having to make a shaky recovery from the sting of the first lesson on what justice really means in this country (around 1984 after making my way through engineering school and still another five years of “paying my dues”), I felt I finally had to take a chance of launching my dream of becoming an independent engineer.

On the subjects of engineers and dreams of independence, I should digress somewhat to say that I’m sure that I inherited the fascination for creative problem solving from my father. I realized this at a very young age.

The significance of independence, however, came much later during my early years of college; at the age of 18 or 19 when I was living on my own as student in an apartment in Harrisburg, Pennsylvania. My neighbor was an elderly retired woman (80+ seemed ancient to me at that age) who was the widowed wife of a retired steel worker. Her husband had worked all his life in the steel mills of central Pennsylvania with promises from big business and the union that, for his 30 years of service, he would have a pension and medical care to look forward to in his retirement. Instead he was one of the thousands who got nothing because the incompetent mill management and corrupt union (not to mention the government) raided their pension funds and stole their retirement. All she had was social security to live on.

In retrospect, the situation was laughable because here I was living on peanut butter and bread (or Ritz crackers when I could afford to splurge) for months at a time. When I got to know this poor figure and heard her story I felt worse for her plight than for my own (I, after all, I thought I had everything to in front of me). I was genuinely appalled at one point, as we exchanged stories and commiserated with each other over our situations, when she in her grandmotherly fashion tried to convince me that I would be “healthier” eating cat food (like her) rather than trying to get all my substance from peanut butter and bread. I couldn’t quite go there, but the impression was made. I decided that I didn’t trust big business to take care of me, and that I would take responsibility for my own future and myself.

Return to the early ‘80s, and here I was off to a terrifying start as a ‘wet-behind-the-ears’ contract software engineer… and two years later, thanks to the fine backroom, midnight effort by the sleazy executives of Arthur Andersen (the very same folks who later brought us Enron and other such calamities) and an equally sleazy New York Senator (Patrick Moynihan), we saw the passage of 1986 tax reform act with its section 1706.

For you who are unfamiliar, here is the core text of the IRS Section 1706, defining the treatment of workers (such as contract engineers) for tax purposes. Visit this link for a conference committee report (http://www.synergistech.com/1706.shtml#ConferenceCommitteeReport) regarding the intended interpretation of Section 1706 and the relevant parts of Section 530, as amended. For information on how these laws affect technical services workers and their clients, read our discussion here (http://www.synergistech.com/ic-taxlaw.shtml).

SEC. 1706. TREATMENT OF CERTAIN TECHNICAL PERSONNEL.

(a) IN GENERAL – Section 530 of the Revenue Act of 1978 is amended by adding at the end thereof the following new subsection:

(d) EXCEPTION. – This section shall not apply in the case of an individual who pursuant to an arrangement between the taxpayer and another person, provides services for such other person as an engineer, designer, drafter, computer programmer, systems analyst, or other similarly skilled worker engaged in a similar line of work.

(b) EFFECTIVE DATE. – The amendment made by this section shall apply to remuneration paid and services rendered after December 31, 1986.

Note:

· “another person” is the client in the traditional job-shop relationship.

· “taxpayer” is the recruiter, broker, agency, or job shop.

· “individual”, “employee”, or “worker” is you.

Admittedly, you need to read the treatment to understand what it is saying but it’s not very complicated. The bottom line is that they may as well have put my name right in the text of section (d). Moreover, they could only have been more blunt if they would have came out and directly declared me a criminal and non-citizen slave. Twenty years later, I still can’t believe my eyes.

During 1987, I spent close to $5000 of my ‘pocket change’, and at least 1000 hours of my time writing, printing, and mailing to any senator, congressman, governor, or slug that might listen; none did, and they universally treated me as if I was wasting their time. I spent countless hours on the L.A. freeways driving to meetings and any and all of the disorganized professional groups who were attempting to mount a campaign against this atrocity. This, only to discover that our efforts were being easily derailed by a few moles from the brokers who were just beginning to enjoy the windfall from the new declaration of their “freedom”. Oh, and don’t forget, for all of the time I was spending on this, I was loosing income that I couldn’t bill clients.

After months of struggling it had clearly gotten to be a futile exercise. The best we could get for all of our trouble is a pronouncement from an IRS mouthpiece that they weren’t going to enforce that provision (read harass engineers and scientists). This immediately proved to be a lie, and the mere existence of the regulation began to have its impact on my bottom line; this, of course, was the intended effect.

Again, rewind my retirement plans back to 0 and shift them into idle. If I had any sense, I clearly should have left abandoned engineering and never looked back.

Instead I got busy working 100-hour workweeks. Then came the L.A. depression of the early 1990s. Our leaders decided that they didn’t need the all of those extra Air Force bases they had in Southern California, so they were closed; just like that. The result was economic devastation in the region that rivaled the widely publicized Texas S&L fiasco. However, because the government caused it, no one gave a shit about all of the young families who lost their homes or street after street of boarded up houses abandoned to the wealthy loan companies who received government funds to “shore up” their windfall. Again, I lost my retirement.

Years later, after weathering a divorce and the constant struggle trying to build some momentum with my business, I find myself once again beginning to finally pick up some speed. Then came the .COM bust and the 911 nightmare. Our leaders decided that all aircraft were grounded for what seemed like an eternity; and long after that, ‘special’ facilities like San Francisco were on security alert for months. This made access to my customers prohibitively expensive. Ironically, after what they had done the Government came to the aid of the airlines with billions of our tax dollars … as usual they left me to rot and die while they bailed out their rich, incompetent cronies WITH MY MONEY! After these events, there went my business but not quite yet all of my retirement and savings.

By this time, I’m thinking that it might be good for a change. Bye to California, I’ll try Austin for a while. So I moved, only to find out that this is a place with a highly inflated sense of self-importance and where damn little real engineering work is done. I’ve never experienced such a hard time finding work. The rates are 1/3 of what I was earning before the crash, because pay rates here are fixed by the three or four large companies in the area who are in collusion to drive down prices and wages… and this happens because the justice department is all on the take and doesn’t give a fuck about serving anyone or anything but themselves and their rich buddies.

To survive, I was forced to cannibalize my savings and retirement, the last of which was a small IRA. This came in a year with mammoth expenses and not a single dollar of income. I filed no return that year thinking that because I didn’t have any income there was no need. The sleazy government decided that they disagreed. But they didn’t notify me in time for me to launch a legal objection so when I attempted to get a protest filed with the court I was told I was no longer entitled to due process because the time to file ran out. Bend over for another $10,000 helping of justice.

So now we come to the present. After my experience with the CPA world, following the business crash I swore that I’d never enter another accountant’s office again. But here I am with a new marriage and a boatload of undocumented income, not to mention an expensive new business asset, a piano, which I had no idea how to handle. After considerable thought I decided that it would be irresponsible NOT to get professional help; a very big mistake.

When we received the forms back I was very optimistic that they were in order. I had taken all of the years information to Bill Ross, and he came back with results very similar to what I was expecting. Except that he had neglected to include the contents of Sheryl’s unreported income; $12,700 worth of it. To make matters worse, Ross knew all along this was missing and I didn’t have a clue until he pointed it out in the middle of the audit. By that time it had become brutally evident that he was representing himself and not me.

This left me stuck in the middle of this disaster trying to defend transactions that have no relationship to anything tax-related (at least the tax-related transactions were poorly documented). Things I never knew anything about and things my wife had no clue would ever matter to anyone. The end result is… well, just look around.

I remember reading about the stock market crash before the “great” depression and how there were wealthy bankers and businessmen jumping out of windows when they realized they screwed up and lost everything. Isn’t it ironic how far we’ve come in 60 years in this country that they now know how to fix that little economic problem; they just steal from the middle class (who doesn’t have any say in it, elections are a joke) to cover their asses and it’s “business-as-usual”. Now when the wealthy fuck up, the poor get to die for the mistakes… isn’t that a clever, tidy solution.

As government agencies go, the FAA is often justifiably referred to as a tombstone agency, though they are hardly alone. The recent presidential puppet GW Bush and his cronies in their eight years certainly reinforced for all of us that this criticism rings equally true for all of the government. Nothing changes unless there is a body count (unless it is in the interest of the wealthy sows at the government trough). In a government full of hypocrites from top to bottom, life is as cheap as their lies and their self-serving laws.

I know I’m hardly the first one to decide I have had all I can stand. It has always been a myth that people have stopped dying for their freedom in this country, and it isn’t limited to the blacks, and poor immigrants. I know there have been countless before me and there are sure to be as many after. But I also know that by not adding my body to the count, I insure nothing will change. I choose to not keep looking over my shoulder at “big brother” while he strips my carcass, I choose not to ignore what is going on all around me, I choose not to pretend that business as usual won’t continue; I have just had enough.

I can only hope that the numbers quickly get too big to be white washed and ignored that the American zombies wake up and revolt; it will take nothing less. I would only hope that by striking a nerve that stimulates the inevitable double standard, knee-jerk government reaction that results in more stupid draconian restrictions people wake up and begin to see the pompous political thugs and their mindless minions for what they are. Sadly, though I spent my entire life trying to believe it wasn’t so, but violence not only is the answer, it is the only answer. The cruel joke is that the really big chunks of shit at the top have known this all along and have been laughing, at and using this awareness against, fools like me all along.

I saw it written once that the definition of insanity is repeating the same process over and over and expecting the outcome to suddenly be different. I am finally ready to stop this insanity. Well, Mr. Big Brother IRS man, let’s try something different; take my pound of flesh and sleep well.

The communist creed: From each according to his ability, to each according to his need.

The capitalist creed: From each according to his gullibility, to each according to his greed.

Joe Stack (1956–2010)

02/18/2010


21
Feb 10

Making Life From Scratch

There is a hypothesis that there was a world filled with life based on RNA which predates our current world where life is based on DNA and protein. Given this hypothesis, this experiment in trying to make life from scratch, based on RNA, is an interesting one indeed.

For the first time, scientists have synthesized RNA enzymes – ribonucleic acid enzymes also known as ribozymes – that can replicate themselves without the help of any proteins or other cellular components.

What’s more, these simple nucleic acids can act as catalysts and continue the process indefinitely.
[...]
The researchers began with ribozymes known to occur naturally, and put these in a growth medium, heated them and allowed the ribozymes to replicate until they had exhausted their fuel – usually within an hour.

The team then extracted a random subset, and put them in a new medium: ribozymes then competed with each other to consume as much of the medium as possible.

Eventually more successful ribozymes came to dominate the culture, and as the process continued, the ribozymes – undergoing evolution – grew in complexity, blindly finding solutions that made them more successful.

“The key thing is it replicates itself, and passes information from parent to progeny down the line,” Joyce told Cosmos Online.

“There’s roughly 30 bits of information passed. Some functions are more fit than others, and those that are more fit ‘breed’ more, and are perpetuated more efficiently, and so it goes Darwinian.”

The ultimate goal is to create genetic systems that behave like life, and are for all intents ‘life’ as we know it, but arose without using biological systems.

“The aim is to create systems that have inventive capabilities, that can develop novel solutions to challenges posed by the environment. But that we don’t have yet,” he said.

“What we do have is a self-sustained chemical system that undergoes Darwinian evolution.
[...]
They are synthetic genetic systems, and they are evolving. But they’re not living because they don’t yet show the capacity to invent a whole cloth of functions.

(Emphasis mine.)

(Link)


17
Feb 10

Mood And Purchasing Behavior

Seems that a person’s mood can affect their purchasing behavior.

The paper is called "The Many Shades of Rose-Colored Glasses: How Positive Emotions Influence Desire for Consumer Products". Here’s an excerpt from ScienceDaily about it….

The authors studied how product preferences changed depending on whether a person was feeling pride, contentment, or a neutral emotional state. Some participants read a short story in which they imagined doing well on an exam, which is known to elicit pride. “We found that pride enhanced desire for public display products,” the authors write. “Feeling pride led people to want nice watches, shoes, and clothing for going out. However, pride did not enhance desire for home products.”

In contrast, the emotion of contentment led people to want products for their homes. “When people felt contentment, they were more attracted to products such as beds, dishwashers, and clothing for lounging around the house,” the authors write. They were less enthusiastic about public display products.

“Our findings suggest that shoppers are likely to want to buy different products depending on the specific emotions that they are feeling,” the authors write. “If a retailer is selling products that allow the consumer to ‘show off’ to other people, this retailer may want to induce feelings of pride through store atmospherics or advertising. In contrast, a retailer selling primarily home furnishings might want to try to induce feelings of contentment.”


17
Feb 10

Looks vs Genes

A nice excerpt from Razib Khan

For whatever reason many salient physical traits which we use to classify populations don’t exhibit the pattern of the total genome, whereby all non-Africans are a branch of the tree of H. sapiens, which mostly consists of African lineages which are much more variegated. Likely new environmental selection pressures once populations left Africa play a role in this.

But there may also be other factors. Biological anthropologist Henry Harpending once explained to me that even if populations exchange genes regularly so as to become indistinguishable on their total genome content, there may be social selection for particular traits correlated with group membership. Harpending explained that on many neutral markers, such as mtDNA lineages, the Bushmen and their Bantu neighbors seem to be relatively undifferentiated. But when it came to physical appearance there was a sharp distinction. Why? Harpending suggested that perhaps there is a strong fitness advantage for someone of mixed ancestry to look more like the group they’re born into. For example, imagine a Bushman man takes a Bantu wife, some of his children favor the father, some the mother. In terms of total genome content all the offspring reflect the parental populations, but on the subset of genes which control traits salient in marking Bushmen-Bantu differences (e.g., epicanthic eye fold) there may be greater fitness to those who carry genotypes which reflect the group into which they’re born.*

Obviously genetics is fascinating to me, and probably you if you’re reading this weblog. When applied to humans it has a very strong emotional impact, consider the popularity of genealogical companies which utilize genetic methods. But it is important to remember that our own intuitive model of our species is to some extent pre-scientific, and mapping colloquial concepts and preconceptions onto scientific findings can result is less than perfect clarity. In this, the 1980s hullabaloo over mitochondrial Eve served as simply a foretaste of what was to come.

* As a toy example, imagine that the epicanthic eye fold is monogenic, controlled by a locus which comes in two flavors, E & e. Those with EE have the fold, those with ee do not, while those with Ee are somewhere in the middle. Imagine that the Bushmen have very high frequencies of EE, while their Bantu neighbors have lower frequencies of the E allele, but not trivial. Imagine if a Bantu woman is of the genotype Ee, while her Bushmen husband is EE. 50% of the offspring would exhibit the Bushmen epicanthic eye fold phenotype. In terms of total genome content these individuals would be no more Bushmen than their Ee siblings, but they would look more Bushmen to others of the tribe, and so might have more success finding a mate due to lower levels of social exclusion. Extrapolate this process generally and you can see how genes which control outwardly salient traits may exhibit more between group difference than the overall genome.

(Link)