Philosophy of Genetics

Genetic differences help explain variation in political participation

According to an article in the American Political Science Review:

...individual genetic differences make up a large and significant portion of the variation in political participation, even after taking socialization and other environmental factors into account.

The authors give no explanation of how differences in our DNA are responsible for such an effect. 

But the answer is not difficult, when you realize that variations in motivation are genetic.  Not everyone wants to be President.  Most of us seek a "just master".  We would rather be followers, not leaders. You just can't teach motivation.

Our genes are responsible for identifying what makes us happy.  Some people are happy being altruistic.  Some are happy being ambitious.  The differences in "wants" and "desires" are accounted for by our genes.  As Schopenhauer wrote, you can do what you want, but you can't want what you want.

I assume people are attracted to the Democratic party (and left-leaning Public Radio) because they feel good about what it stands for.  Others (with a different set of genetic variants) are attracted to the Republican party (and Fox News).

I think the more interesting question is: how do our genes affect the construction of our mind and brain, to account for these differences in desires, pleasures, motivators?  How did our DNA create the brain in such a way that we can differentially get motivated by different qualities of political parties?

Why can't a mouse be more like a man?

New drugs are usually tested and perfected in mice, before they are ever given to humans.  Mice make dependable subjects in a lab, and a drug that proves safe and effective in a mouse may very well be safe for humans.

But, alas, a mouse is not a man.  Too often, drugs show an effect in animals, but have little effect in humans. More importantly, drugs that prove safe for animals may have unwanted side-effects in humans.

For this reason, scientists are trying to make mice more "human-like", to make their drug response more predictive of human drug response.  Mice have different genes from humans (although there is at least a 95% DNA similarity), and this leads them to metabolize drugs differently.  So mice with more human-like genes are being genetically engineered for use in drug-testing.  A mouse can be more like a man, after all.

Yet any study (whether mouse or human) adds to the cost of developing new drugs.  So some scientists are also attempting to develop predictive computer models (in silico), to simulate (on a computer) the drug's effect on the body (such as "predicted liver toxicity"), without requiring as many animal studies.

But human studies will always be needed to test new drugs.  The human body is too complex and our genes are too unique from other animals to fully rely on other predictive models.

Out of Africa

In the beginning, there were no Whites and no Asians.  We were all Africans.

According to genetic studies, all humans evolved from a single female (named “Eve”) who lived in Africa 200,000 years ago.

How do we know?  Each generation, there are subtle changes in our DNA, which normally have little effect.  These DNA changes accumulate over time, as they are passed down from one generation to the next, and their frequency can be used for analysis of human migrations through history.  The further away from Africa you travel, the less genetic variability you see, implying that Africa was the ancient birthplace of modern man.

Sometimes these small DNA changes (or “genetic drifts”) are given specific names, to represent family branches, especially when new human migrations occur:

• After Eve, the L1 lineage branched off (some 125,500–165,500 years ago).  Today, the San and Mbuti peoples of Africa are Eve's direct descendants.  They set the stage for behavioral modernity between 100,000-50,000 years ago, when humans began to think more abstractly, engage in bartering and trade, and develop language and music
• Then, the L2 line branched off from the L1 line (around 70,000 years ago), and populated parts of western Africa.
• Another lineage, L3, also branched off from L1 (around 60,000 years ago), and populated parts of northeastern Africa

The L* lines are now largely confined to Africa (except those people who emigrated in the last 400 years, or, in that terrible chapter of human history, were captured and sold elsewhere as slaves).

• Around 60,000 years ago, a new branch, the M lineage, split from the L3 line and departed from Africa and crossed the Red Sea into the Middle East.
• From there, the M lineage migrated to Asia, and a new N lineage migrated to Europe. There are very few of the M lineage in Europe, but there are N's mixed with M's in Asia.
• Later (14,000 years ago, although some say it was 30,000 years ago), some Asians migrated across the Bering Straight to populate North and South America.  These are the American Indians, and other native peoples

In summary, if someone asks you where you're from originally, you'd never be wrong to say "Africa".

Al Gore's DNA

Former vice president Al Gore recently helped launch Navigenics, a new personal genomics service.  According to Gore, "on all these new genetic breakthroughs, there is always some resistance culturally, and then, where there's an evaluation of the inherent value, if the ethics are right, if the surrounding culture is right, then it just breaks through ... I think it's going to be a fantastic success."

Using Navigenics' service, you can determine your projected lifetime risk for certain conditions like heart disease, based on your personal genetic differences.

The Personal Genome Project

Harvard's George Church (with help from Google) plans to identify the genetic variations of 100,000 people (and perhaps eventually 1,000,000 people), and associate their gene variants with their health and family disease history.

According to a recent article in Bloomberg:

By matching genetic data from each person with his or her health history, Church would build a database that would link DNA variations and disease for scientists and drugmakers, the first step in deciding on treatments that can block the mutations or adjust how they work within the body. Church also said he'll explore other human traits under genetic control. Participants will give facial and body measurements, tell researchers what time they get up in the morning, and detail other behaviors, he said.

Previously, it's been difficult for scientists to determine which specific gene variants are responsible for disease, without having this much data to analyze.  There are 3 million "single letter" DNA differences between people (which account for 10% of the total genetic variation).  In order to make statistically valid associations between genetic variation and disease, you need to study the gene variants of hundreds of thousands (if not millions) of people.

Google is positioning itself to help consumers keep track of their complex genetic data, and self-manage their electronic healthcare records.  The U.S. Congress is lagging behind the rapid technology advances, and should immediately pass legislation that prohibits any genetic discrimination, especially by insurance providers.

What is a Chimera?

According to the New England Journal of Medicine, a woman named Lydia Fairchild gave birth to her own child in 2002, but genetic tests performed on her skin and hair did not match her child (except to the degree a grandmother might match).

However, DNA from other tissue in Fairchild's body did match her child. Lydia carried two distinct sets of DNA within her body, the defining characteristic of a chimera.

The most likely explanation is that Lydia Fairchild herself was a fusion of two sets of chromosomes from her parents, when she was born. Her mother simultaneously ovulated two eggs, which were both fertilized by different sperm from her father.  Then the two eggs fused into a single embryo, which grew up to be Lydia.

In other words, as Lydia Fairchild developed, both types of cells within her participated in constructing her various organs, but not all the DNA was represented in all her organs.  She had two distinct sets of DNA, as if she had twins inside her own body.

So when Lydia Fairchild had a child of her own, the child inherited one set of her DNA, but not the other set.

How many genes does it take to create life?

How many genes does it take to create life? Mycoplasma genitalium bacteria has 485 genes, and this is the fewest for any free-living organism. But 103 of its genes can be individually removed without killing it, so 382 genes seem to be essential for life.

At the J. Craig Venter Institute, scientists are assembling those 382 genes from scratch to synthesize new organisms. Their hope is to insert additional genes along the way, to generate useful bi-products.  Synthetic bacteria with added genes could become "trillion dollar organisms". For example, large vats of "enhanced" bacterium could produce bio-fuels (or any other organic product), and launch entirely new industries.

1000 Genomes Project

An international research consortium has announced it will sequence the complete DNA of 1,000 people.  The goal is to "catalog [DNA] variants that are present at 1 percent or greater frequency in the human population". The project will focus not only on mapping single-letter differences in DNA, but also "structural variants" such as DNA rearrangements, deletions or duplications of segments.

According to ScienceDaily: "It is important to understand the small fraction of genetic material that varies among people because it can help explain individual differences in susceptibility to disease, response to drugs or reaction to environmental factors."

Effects of variations in your DNA

If you like Wikipedia, you'll love the new SNPedia, which lists the effects of variations in your DNA (known as SNPs). Want to know what gene variants you have? Subscribe to 23andme.com. For the intrepid, you can also try the new Personal Genome Explorer.

Dusty old volumes from our Genetic Library

It seems that the process of evolution makes good use of old knowledge, stored away in our DNA library.  A new study shows how ancient DNA fragments (which are really just encapsulated knowledge from the pre-historic past) can be revived and applied, to design new forms of life, through changes to the genetic regulatory system.

Apologies for my lack of posts recently.  I'm writing a novel, based on this blog!  Should have something to show for it in the next month or two.