I have a fondness for graphs, especially ones that let you survey the sweep of life’s history in one glance. Here’s a new one, out today in the journal Science. It’s the latest look at the levels of biodiversity over the past half billion years. Scientists crunched the numbers on about 3.5 million fossils of ocean-dwelling invertebrates, using more detailed data than in previous surveys. (Some marine invertebrates leave fabulous heaps of fossils. Other species, like our own, are more delicate.) The horizontal axis marks time, and the vertical one marks the number of genera alive at any particular interval of about 10 million years. (Genera are groups of species. The genus Homo includes us, Neanderthals, and a few other extinct hominids, for example.)
Rebecca writes:
“Attached is a picture of my science tattoo. It is a Marsh Pick, with a series of Pentaceratops vertebra, and a blue peace sign. I am a vertebrate paleontologist and geologist who works on ceratopsid dinosaurs. Since I am a southerner, I choose a southern species of ceratopsian (Pentaceratops sternbergi), from New Mexico. I love the color blue, so I went with the blue peace sign. The whole design is based after the Society of Vertebrate Paleontology, but altered to fit my specific passions.”
I’m going to be posting my blogroll to my new digs as soon as I get the chance. And to that list I will be adding BdellaNea. It’s the work of Mark Siddall, a scientist at the American Museum of Natural History who specializes in leeches.
I wrote about Mark in this 2006 article for the New York Times, and last weekend at the meeting of the American Society for Parasitologists we caught up briefly. He’d been off to Zambia and various other seething leech hot spots since I’d last seen him, and at the meeting he and his students were presenting lots of new research, including some insights into how different species of leeches thin your blood.
Continue reading “A Leech Blog. If You Build It, We Will Come.”
Robert writes:
“Hi Carl,
I like your blog. It inspired me in some way to do the tattoo that I’ve been thinking of for several years 🙂
Here’s an explanation:
I have several reasons for choosing a sigma. The simple reason is that I think sigma is really beautiful, especially when using this LaTeX font 🙂 The tattoo also represents my love of mathematics in general, and of the beauty of abstract patterns in particular.
Scientific American, July 1, 2008
NATURAL SELECTION IS NOT NATURAL PERFECTION. Living creatures have evolved some remarkably complex adaptations, but we are still very vulnerable to disease. Among the most tragic of those ills—and perhaps most enigmatic—is cancer. A cancerous tumor is exquisitely well adapted for survival in its own grotesque way. Its cells continue to divide long after ordinary cells would stop. They destroy surrounding tissues to make room for themselves, and they trick the body into supplying them with energy to grow even larger. But the tumors that afflict us are not foreign parasites that have acquired sophisticated strategies for attacking our bodies. They are made of our own cells, turned against us.