Mediocre Poison Eaters And The Imperfection of Evolution

Posted on by Matt Kristoffersen

It’s easy to forget sometimes that evolution is always a work in progress. We contemplate the eye or look upon an oak tree, and ask, how could they be any better? Somehow, in those moments of awe, we forget about detached retinas and sudden oak death. The evolutionary race is not in fact won by the perfect, but by the good-enough. And it just so happens that one of the best illustrations of evolution’s mediocrity is unfolding in front of us right now.

This episode of evolution is entirely of our own doing. In 1936, a chemical called pentachlorophenol went on the market. It was hugely popular as a way to preserve telephone poles and lumber against fungi and termites. Unfortunately, it also turned out to be toxic to humans, and once it got into the soil it could contaminate the ground for years. That’s because the molecule–five chlorine atoms decorating a ring of carbon atoms–had not previously existed in nature. Microbes had not evolved to feed on it before. It was as toxic to them as it was to us.

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From Fearsome Predator to Man’s Best Friend

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The New York Times, May 16, 2013

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Imagine a wolf catching a Frisbee a dozen times in a row, or leading police officers to a stash of cocaine, or just sleeping peacefully next to you on your couch. It’s a stretch, to say the least. Dogs may have evolved from wolves, but the minds of the two canines are profoundly different.

Dog brains, as I wrote last month in The New York Times, have become exquisitely tuned to our own. Scientists are now zeroing in on some of the genes that were crucial to the rewiring of dog brains.

Their results are fascinating, and not only because they can help us understand how dogs turned into man’s best friend.

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How To Evolve a Dog’s Brain (And A Human One, While We’re At It)

Posted on by Matt Kristoffersen

It’s Thursday, and that means that I’m publishing my next piece for Matter, my weekly column for the New York Times. Today, I take a look at dogs. Last month I wrote in the Times about cognitive scientists playing games with dogs to probe their behavior. But that’s just part of the story of canine research these days. There are also geneticists out there looking at the same question from a different perspective. They want to find the genes that evolved over the past 30,000 years or so to turn the brain of a wolf into the brain of a dog. The answers are now starting to emerge, and they’re fascinating. They may, in fact, tell us a lot about how we became humans. Check it out!

Originally published May 16, 2013. Copyright 2013 Carl Zimmer.

Tracing Breast Cancer’s History

Posted on by Matt Kristoffersen

In today’s New York Times, the actress Angelina Jolie published a remarkably forthcoming op-ed about getting a double mastectomy. Jolie carries a variant of a gene called BRCA1 that makes women highly likely to develop breast and ovarian cancer. Her mother, who also carried the variant, died of ovarian cancer at age 56. Like a number of other women with her condition, Jolie decided to get a mastectomy as a preventative measure.

A number of studies have shown that bilateral risk-reducing mastectomies (the official term) do indeed reduce the risk of breast cancer in women with the BRCA1 mutation. In a study published last month in Annals of Oncology, a team of Dutch medical researchers tracked 570 women with BRCA1 (or a mutation in the related gene BRCA2). At the start of the study, all the women were healthy; 212 of them later chose to get risk-reducing mastectomies. Over the next few years, the researchers followed their progress. Sixteen percent of the women who didn’t get risk-reducing mastectomies developed breast cancer; of the women who went Jolie’s route, none did.

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