Cats and Isotopes

A domestic cat in a bag.

A domestic cat in a bag.

Cats. The very mention of them has the power to generate innumerable lazy hits on a blog post. If one were to do an anthropological study of cats using only the Internet as source material, one might be lead to believe that we worship them as deities.

We wouldn’t be the first culture, either. The ancient Egyptians held them in pretty high regard. Their goddess of justice and execution, Mafdet, was a feline-headed creature who protected against snakes and scorpions. Baset, another feline goddess, represented protection, fertility, and motherhood.

Despite the high regard humans have had for cats since at least the dawn of written history, we know very little about how or when they became domesticated. We are pretty sure that the housecat is descended from the African wildcat (Felis silvestris lybica), and people generally assume the process involved a mutually beneficial relationship between farmers and felines in which the cats protected the farmer’s grain from vermin, and the grain provided for a steady supply of vermin for them to eat.

But it is really hard to figure out when that would have happened, and even harder to figure out if that general picture, which makes a great deal of heuristic sense, is accurate.  A recent study on this subject published by a team of archeologists got a great deal of press. They found a small Chinese farming village dated to about 5300 years ago with cat and rodent fossils (among others) discovered at the site.

The basic gist of the study was that chemical analysis of the animal bones found at the site revealed that the rodents ate grain, and that the cats ate those rodents or the grain products directly—suggesting a mutually tolerant relationship between human and cat. Other wild animals found at the site, like deer and hares, didn’t seem to eat any grain, suggesting their food web was independent of any human influence. It’s a fascinating and impressive result, and it seems to be consistent with the generally accepted theory of cat domestication.

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Science Smackdown: Tattoos Vs. Piercings


Lauren’s shoulder, freshly inked.

The needle doesn’t even hurt—it just scratches meekly at my shoulder blade, like the world’s most gentle kitten sharpening its claws. I relax my grip on my friend Lauren’s hand just enough to give her back her pulse. Fifteen minutes later and it’s over. “All done,” says Kevin, my tattoo artist, and before I know it I’m climbing off the green surgical bed with a Band-aid and a distinct sense of anti-climax.

I suppose I’d expected my first tattoo to feel a bit more … momentous. Instead, it was basically like when I was 16 and got my nose pierced. That experience went something like this:





Actually, when I thought about it, the two were quite similar. Both involved needles, pain, and permanence. Both, teenage me thought, would help me express to the world how special and unique I was through my most easy-to-access canvas: my skin. Both have been practiced for thousands of years, and disapproved of for just as long. “Ye shall not make any cuttings in your flesh for the dead, nor print any marks upon you,” says the Bible (Leviticus 19:28). “Whyyyy?!” says my mom.

They can’t be all that bad, I thought. So I decided to consult science on the matter: Which is worse, a piercing or a tattoo? Read the rest of this entry »

What are we missing?

House Fire

A house on Edgewood Avenue (I think) north of Baltimore in 2009. A found story for a community newspaper reporter. More often than not, however, science writing offers few “found” news stories.

I sometimes worry that important discoveries, breakthroughs, and innovations are happening and no one is writing the stories. What might be a historic moment might be barely recorded, and will appear in high school textbooks 100 years from now looking like this:

While the dual-chronograph, high-alpha wormhole inducer remains the keystone technology making interstellar travel commonplace today, few accounts remain of its creation or whether the inventors recognized its significance at the time.

When I was a community newspaper reporter, I sometimes found story topics by bumping into them. On one telling occasion I was driving through my coverage area, probably to or from an interview — I can’t remember the scenario because it was a few years ago — and I must have made a wrong turn because I can’t remember why I was on a certain street just north of Baltimore. I then passed a burned out house. I pulled over, walked through the house, took photos inside and out, and asked neighbors about the person who lived there.

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Beautiful Starling Murmurations Use Rome As A Toilet

It was dusk and mildly chilly in Rome when I stepped out of Roma Termini, the city’s busy central train station, and heard relentless screeching noises from above. I looked up to see thousands of birds covering the treetops like bees on a honeycomb. A cloud of them sprang from one tree only to quickly dissolve into another. Bigger clouds of black specks curled and twisted even higher, over rooftops and looming cranes.

Starlings. Thousands of them, and just a small portion of the 1 to 5 million that overwinter in Italy’s capital.

To nature lovers, starling swarms – called “murmurations” – are fascinating and beautiful. Stunning videos of murmurations have captured the admiration of the Internet. They’re also a favorite example of swarming science, each individual bird following cues on speed and direction from its neighbors to form a massive, swirling shape in the sky.

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Human Minds Vs. Large Numbers, Round 2

Meet Bob. He’s in his late fifties, a quiet guy, wears rimless spectacles, and likes to read poetry. Do you think Bob is a classics professor or a truck driver?


If you answered classics professor, you’re with the vast majority of people asked this question. Quiet, spectacles, poetry reader, all of it pretty well fits the common image of a classics professor and not so much our image of a truck driver. But while there are approximately 7500, maybe at a stretch 10000 classics professors in the US, that number is blown out of the water by a couple orders of magnitude when compared with how many truck drivers there are. The American Trucking Association’s website says there are 3,500,000 truck drivers in the country, making it much, much more likely that Bob is a quiet, poetry-reading truck driver. He may not fit the NASCAR-loving truck driver stereotype, but it’s still more likely.

It’s much more likely, but that’s not the way we think. Humans look for patterns, make categories, and form stereotypes in order to make sense of the world. If our early ancestors heard a scream, they did not sit down to calculate the probability that their friend Og had trod on a surprise thorn bush versus the probability that Og had just been snack for a saber-toothed tiger. No, they used their learned pattern of scream = bad and got the hell out of there.

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