By analyzing genetic material on $1 bills, the NYU researchers identified 3,000 types of bacteria in all — many times more than in previous studies that examined samples under a microscope. Even so, they could identify only about 20% of the non-human DNA they found because so many microorganisms haven’t yet been cataloged in genetic data banks.

Easily the most abundant species they found is one that causes acne. Others were linked to gastric ulcers, pneumonia, food poisoning and staph infections, the scientists said. Some carried genes responsible for antibiotic resistance. (WSJ)

Children with a parent who has a specific chronic health condition are at least 100% more likely to have the same condition themselves. To assess the role of genetic mechanisms in generating these strong correlations, I estimate models using a sample of approximately 2,400 adoptees, and find that genetic transmission accounts for only 20%-30% of the baseline associations.

Paper. HT: Jason Shafrin.

To a striking extent, your overall life chances can be predicted not just from your parents’ status but also from your great-great-great-grandparents’…The fortunes of high-status families inexorably fall, and those of low-status families rise, toward the average — what social scientists call “regression to the mean” — but the process can take 10 to 15 generations (300 to 450 years), much longer than most social scientists have estimated in the past…

Does this imply that individuals have no control over their life outcomes? No. In modern meritocratic societies, success still depends on individual effort. Our findings suggest, however, that the compulsion to strive, the talent to prosper and the ability to overcome failure are strongly inherited. We can’t know for certain what the mechanism of that inheritance is, though we know that genetics plays a surprisingly strong role. Alternative explanations that are in vogue — cultural traits, family economic resources, social networks — don’t hold up to scrutiny…

The notion of genetic transmission of “social competence” — some mysterious mix of drive and ability — may unsettle us. But studies of adoption, in some ways the most dramatic of social interventions, support this view. A number of studies of adopted children in the United States and Nordic countries show convincingly that their life chances are more strongly predicted from their biological parents than their adoptive families. In America, for example, the I.Q. of adopted children correlates with their adoptive parents’ when they are young, but the correlation is close to zero by adulthood. There is a low correlation between the incomes and educational attainment of adopted children and those of their adoptive parents.

These studies, along with studies of correlations across various types of siblings (identical twins, fraternal twins, half siblings) suggest that genetics is the main carrier of social status.

Full piece worth reading.

…”[G]enome-wide” surveys examine the links between a trait and all of the 20,000 or so human genes.

This has been an extraordinarily powerful approach. For the most part, what has emerged from these studies is evidence of the minimal extent to which some trait is “in your genes” and of how relatively unimportant any given gene is.

Height:

The single genetic variant that was most powerfully associated with growth explained just 0.4% of the variation in growth, and all the hundreds of identified variants put together explained only about 10% of the variation — which is not a lot of explanatory power.

Body Mass:

An equally acclaimed study used similar techniques to study body-mass index (BMI). After research on nearly 250,000 subjects, the genetic variant most clearly identified with BMI accounted for only 0.3% of the variation.

Educational attainment:

The most predictive single genetic variant accounted for 0.02% of the variation between individuals. Putting together all of the identified genetic variants explained only about 2% of the total variation.

Source: The Wall Street Journal.

Yale law professor Stephen Carter reports:

The U.K. may soon approve a regulatory proposal that would allow scientists to create a human embryo using the DNA of three individuals. The idea is to remove damaged maternal DNA and replace it with genetic material from another woman, in order to reduce the risk of transmitting a mitochondrial disorder.

And here’s the rub:

This all sounds on the surface very clean and high-tech and altruistic. Yet it turns out that lots of people oppose it, including members of the Parliamentary Assembly of the Council of Europe and members of the European Parliament involved in its Bioethics Intergroup. What’s striking is how the opponents span the political spectrum. The open letter from the Bioethics Intergroup, for example, was signed by representatives of both the Conservative and Green parties.

Full piece is worth reading. Then tell us what you think in the comments.

The first IVF baby to be screened using a procedure that can read every letter of the human genome has been born in the U.S.

Connor Levy was born on 18 May after a Philadelphia couple had cells from their IVF embryos sent to specialists in Oxford, who checked them for genetic abnormalities. The process helped doctors at the couple’s fertility clinic in the U.S. select embryos with the right number of chromosomes. These have a much higher chance of leading to a healthy baby.

The birth demonstrates how next-generation sequencing (NGS), which was developed to read whole genomes quickly and cheaply, is poised to transform the selection of embryos in IVF clinics. Though scientists only looked at chromosomes — the structures that hold genes — on this occasion, the falling cost of whole genome sequencing means doctors could soon read all the DNA of IVF embryos before choosing which to implant in the mother. (More)