CHRISTINE KENNEALLY

The sins of the fathers may be visited on the deoxyribose nucleic acids of the sons. I wrote about the "Epigenetics: The Ultimate Mystery of Inheritance" for Slate.

Since 2004, I’ve spent a lot of time staring at the ceiling thinking about tsunamis and earthquakes. The monster wave that hit Indonesia that year was caused by a earthquake so violent it shifted the axis of the earth a few centimeters. Now I can’t get this out of my mind: The planet literally shook.

Everyone has one--whether its global warming, phthalates, flu, or junk food--it's that thought that makes them quake. Still, despite the fear, most people do their best to live sustainably, heal naturally, and raise their children right.

But how often is it that one's efforts feel good enough? For the most part, the solutions are inadequate or unachievable or overwhelmingly, confusingly both. If you turn on the air conditioner because you are too warm, you cause global warming. If you vaccinate your children to protect them, you fear the vaccine may hurt them, and yet if you get cancer, it’s your fault for being so angry and fearful all the time. What if you don’t actually want to walk to the local abattoir and slaughter your own pig so you can eat your sausages morally? What does that even mean?

You could consider optimism, for a change. I thought about it a lot when I reviewed Matt Ridley's "The Rational Optimist."

The New York Times Science section has an excellent evolution special this week. Of particular interest is Nicholas Wade's article on the very recent evolution of human populations. There is more and more evidence that culture has shaped the human genome. Also fascinating is Cornelia Dean's inquiry into what has happened to the human soul. Evolve locally, Science of the Soul.

Two variants of the genes ASPM and Microcephalin may make it easier to learn tone languages. If you have the tone-versions, as do most speakers of Chinese (and other languages such as those found in South East Asia and sub-Saharan Africa), you may be more adept at learning languages that distinguish words with pitch as opposed to those that don't. This is the first time it's been shown that possessing a particular form of gene, let alone two, may impact the way we learn language.  The dogma has always been that we are all born with precisely the same genetic program which builds exactly the same neural equipment for language. The Times, Scientific American, PNAS.