My ancestry forms a smear across northern and central Europe, a region of the world where many people have a peculiar gift: they can drink milk as adults. Almost all people can digest milk sugar (lactose) as babies, but in many parts of the world they lose this ability after they stop nursing. The change is due to an enzyme called lactase, which breaks down lactose into digestible fragments. Most people stop making lactase as they grow up. If they drink milk, the lactose builds up in their guts, where it can be devoured by microbes that produce gas and other discomforts. (It’s not so unpleasant for such people to eat cheese or yogurt that’s low in lactose or which contains bacteria that make their own lactase.)

Continue reading “In the footsteps of my lactose-intolerant ancestors” →

Tomorrow I’m heading down to New York to take part in the “Inside Out” speaker series at New York University’s Department of Journalism. John Rennie, editor-in-chief at Scientific American, and I will try to answer the question, “Can two prominent magazine journalists find happiness blogging?” The inquisition, run by LA Times reporter and NYU writer-in-residence Lee Hotz is open to journalism students and faculty. It will take place the fifth floor atrium of 10 Washington Place, at 6 p.m on Tuesday. See you there. 

Originally published February 26, 2007. Copyright 2007 Carl Zimmer.

Loyalty, teamwork, cruel deception: welcome to robot evolution.

Living things communicate all the time. They bark, they glow, they make a stink, they thwack the ground. How their communication evolved is the sort of big question that keeps lots of biologists busy for entire careers. One of the reasons it’s so big is that there are many different things that organisms communicate. A frog may sing to attract mates. A plant may give off a chemical to attract parasitoid wasps to attack the bugs chewing its leaves. An ant may lay down pheromone trails to guide other ants to food. Bacteria emit chemical signals to each other so that they can build biofilms that line our lungs and guts.

Continue reading “Evolving Robotspeak” →

The Koufax awards are among the biggest honors out here in the blogmos. It just came to my attention that the Loom has been nominated in the category of best writing. Of course, I’m packed in with lots of excellent blogs, so if you plan to vote, you’ve got lots of reading ahead of you. When voting does open up, prepare for a not-so-subtle reminder…

Best Writing Nominations | The Koufax Awards 

Originally published February 23, 2007. Copyright 2007 Carl Zimmer.

There was a time–in the 1960s and 1970s–when the phrase “Man the Hunter” enjoyed a lot of popularity. Some researchers claimed that the evolution of hunting played a key role in the origin of our lineage. That’s what we made tools for, and that’s how we got all the extra energy to fuel our big brains. Much of our anatomy, according to the Man-the-Hunter theory, was the result of adaptations for hunting. You have to stand tall above the savannah grass, for example, to spot your game. You need to make weapons. And a bloody-minded psychology helped too.

Continue reading “Woman the Hunter?” →