- Nothing more until the summer!
Category Archives: Natural Sciences
Life achievement unlocked: today for the first time I marched in a major political protest on the streets of Washington, D.C. As a member of the March for Science, I walked from the Washington Monument grounds, within sight of the White House, down Constitution Avenue to 3rd Street, on the fringe of the Capitol grounds. Weather conditions at the rally were less than ideal (drizzle and showers), but I stuck to the principle that there is no such thing as bad weather, just inappropriate clothing.
I walked with a group well-organized by Audubon Naturalist Society (that’s us mustering on the steps of the National Museum of Natural History). ANS’s march leaders had the brain wave of bringing decorative bird spinners as a rallying point. The spinners (and the stylin’ t-shirts) brought us lots of attention, especially from journalists major and minor.
That’s how it was. It was like we had had something in Jefferson for eighteen years and whether it has been right or whether it had been wrong to begin with didn’t matter anymore now because it was ours, we had lived with it and now it didn’t even show a scar, like the nail driven into the tree years ago that violated and outraged and anguished that tree. Except that the tree hasn’t got much choice either: either to put principle above sap and refuse the outrage and next year’s sap both, or accept the outrage and the sap for the privilege of going on being a tree as long as it can, until in time the nail disappears. It dont go away; it just stops being so glaring in sight, barked over; there is a lump, a bump of course, but after a while the other trees forgive that and everything else accepts that tree and that bump too until one day the saw or the axe goes into it and hits that old nail.—William Faulkner, The Town, chap. 19
Dan Pletscher remembers wildlife biologist John Craighead, in conversation with John Burnham.
Ed Yong has put together an excellent background piece about the outbreak of Proliferative Kidney Disease that has killed whitefish and threatens trout species. The fish kills led Montana Fish, Wildlife and Parks (FWP) to shut down of 183 miles of the Yellowstone River. The coverage elsewhere that I saw simply repeated the FWP statement that a “microscopic parasite” was responsible and left it at that. But Yong did the reading, and used it to describe the peculiar morphology and life cycle of the infectious parasite Tetracapsuloides bryosalmonae, a jellyfish relative and one of the myxozoans.
Myxozoans have performed a crazy evolutionary double-back:
In this free-swimming form, they look very jellyfish-like, with identifiable tentacles, mouths, and guts. Perhaps the ancestors of myxozoans went through a similar phase in their evolutionary history, when they were already devoted parasites, but still kept some obvious traces of their cnidarian heritage.
As they evolved further down the parasitic path, they lost these ancestral physical features. They did away with many genes too. “They have the smallest known animal genomes,” says [Paulyn] Cartwright [at the University of Kansas], “and they lack some of the genes that we consider hallmarks of animal development.” For example, the all-important Hox genes, which direct the construction of animal bodies… are simply missing in myxozoans.
Emily Helliwell explains her approach to talking with creationists. In short, focus on the concepts that are important to the here and now:
If we want to get back to the dinosaurs, we can say the cumulative effect of billions of years of changing environments have allowed for some pretty amazing creatures to come and go. But, let’s resist the urge to talk about that, and stay focused on the small-scale stuff. Because if there is any concept necessary for our modern, developed society to believe in and understand, it’s microevolution.
Through microevolutionary principles, we would not have developed two of the most important contributions to society, antibiotics and pesticides. Without antibiotics, we would be subject to horrible infections, and without pesticides, we would be subject to devastating crop failures. Many of us would be dead or suffering.
Callan Bentley turns the screws on a diamond anvil cell. Pressures inside the cell, a little gizmo smaller than a snow dome, are on the order of 60 GPa. He writes:
- 60 gigapascals is therefore a pressure equivalent to about 2100 kilometers of depth in the planet – most of the way through the mantle, though not quite to the outer core (which is at ~2900 km depth).
- A pressure cooker cooks at 0.0001 GPa.
- Your car’s tires are inflated to a pressure of 0.0002 GPa (2 bars, or ~30 psi).
- 60 GPa is a lot more than 0.0002 Gpa.
(Sorry, but I had to go to that song.)
A couple of orb weaver spiders have taken up residence in webs strung across my back door. This one is a bit longer than a centimeter from head to abdomen; the other is significantly smaller, but its markings are similar. Here’s hoping that someone familiar with mid-Atlantic arachnids can help me out with an ID.
The complete Macaulay Library of natural sounds, with some recordings going back to 1929, has been fully digitized by the Cornell Lab of Ornithology and made available online.
[Trevor] Pinch has made a career of studying how scientists listen. He notes that listening has certain advantages over vision. “The visual field is kind of in front of us — like a kind of screen,” he says, while sound is “all around.”
If seeing is like being in an art gallery, hearing is more like being in a swimming pool — where we’re swimming all the time.
Dave Taft offers a splendid 24-hours sampler of the wildlife to be found within New York City, be it animal, vegetable, or fungal; native or alien invasive. He even finds something remarkable about the ickiest species on his list, Macrobdella decora:
Generally an animal no one wants to find, the American medicinal leech is attractive, as far as leeches go. Green or dark brown overall, this native leech has orange spots with a lighter belly.
The color illustrations by Matt McCann, in the online edition of this story, really pop.
Oh, one more from the links pile: a gorgeously illustrated post by Scott K. Johnson about the geology of California’s Sierra Nevada. Is the mountain range rising or falling? We still don’t really know.
That might disappoint people who just want a simple answer, but messy fields of research are interesting fields of research. As Greg Stock [geologist for Yosemite National Park] described it, “Part of what’s been fun about being involved in this issue of Sierra uplift, for a couple of decades now, is that every so often—actually pretty often—a paper will come out that really challenges a lot of what we thought we had accepted before. Even though I know it’s a little frustrating for our interpreter rangers here [at Yosemite], who kind of want a nice clean story to tell the public, I have to tell them—no, no, this is great, because this is the way science works. And it’s a great thing to be involved in a field of study that is this turbulent.”