Scutigera coleoptrata


Photograph by Mark Sturtevant.
Photography contest, Honorable Mention.

Scutigera coleoptrata. Dr. Sturtevant writes, "The charming face of a house centipede. The ‘fangs’ are actually a modified pair of front legs. House centipedes originated in the Mediterranean region, but are now friendly household guests around the world."

Is editing germ cells ethical?


Readers know by now that a Chinese scientist, He Jiankui, announced to the press that he and his team had genetically modified the DNA of twin baby girls. Specifically, his purpose was to delete a certain gene and render the girls immune to infection by HIV. The fathers of both girls were HIV-positive, but the mothers were not. Questions immediately arose as to the ethics of the procedure, which many experts thought was premature. You may find good articles in Science, The Los Angeles Times, and Nature, and a good radio program on NPR.

The LA Times article features an interview with Michael Snyder, the director of the Center for Genomics and Personalized Medicine at Stanford University. Dr. Snyder notes that germ-line editing, such as Dr. He performed, is “more consequential” than editing somatic cells in an individual. He notes, as do others, that editing the germ cells can result in unintended changes elsewhere in the DNA. These unintended changes can be harmful and may be passed from generation to generation. Further, the procedure has not been tested on primates to ensure its safety. At best, then, Dr. He’s procedure was premature.

I was surprised to learn from the Science article that the risk of transmitting HIV from the father to the children was negligible. Unless I missed it, I did not encounter that claim anywhere else. To my mind, that changes the ethics greatly: The procedure was not, as I had incorrectly inferred, a last-ditch effort to allow these men to have children (there were a number of unsuccessful attempts before the researchers achieved success). Dr. He explained that he only wanted to protect the babies from contracting HIV when they were older. I find it hard to argue with Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, who told Science, “There are so many ways to adequately, efficiently, and definitively protect yourself against HIV that the thought of editing the genes of an embryo … in my mind is unethical.”

In my mind too. What do others think? Would it be ethical if it were protecting the babies from immediate harm?

Climate Assessment published, rejected

Report cover
Photograph credit: National Park Service.

I think it was Jared Diamond (though it may have been me) who said that the person who cut down the last palm tree on Easter Island was probably simultaneously calling for another study. The Fourth National Climate Assessment has been published, and it seems fairly definitive. David Malakoff, writing in Science, calls it a sobering message and says,

Climate change is already being felt in communities across the United States, and will cause growing harm to the economy, infrastructure, and human and ecological health—unless the United States and other nations take concerted action to reduce emissions of warming gases and adapt to a warmer world.

Far from calling for another study, the White House, having released the report the day after Thanksgiving, essentially rejected its conclusions. The website FYI: Science Policy News from AIP [The American Institute of Physics] comments,



Photograph by Dan Phelps.

Moldavite. Mr. Phelps writes, "I’ve had this moldavite for a number of years. I showed it in class today during my discussion of tektite formation. I used one of those ultra bright tactical flashlights to backlight the specimen ... (taken with my iPad)." The fingers belong to the photographer.