Going beyond

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.

Modern agriculture

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.

Under pressure

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.)

Transportable

Christopher Joyce and Bill McQuay inaugurate the series Close Listening. The editing on the piece is a little Radiolab-ish for my taste, but the sounds of science are ear-opening.

[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.

The city that never sleeps

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.

Plunging

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.”

VNPS Winter Workshop 2015

A really strong workshop, with four good speakers, hosted by Virginia Native Plant Society at the University of Richmond. A theme emerged: interactions of plants with other organisms in the landscape, be they herbivorous White-tailed Deer (Odocoileus virginianus) (as discussed by Henry Wilbur, emeritus at the University of Virginia), or pollinating Eastern Tiger Swallowtails (Papilio glauca), who pick up pollen from Flame Azalea (Rhododendron calendulaceum) on their wings (only the second such association known, as discovered by Mary Jane Epps, postdoc at North Carolina State University [her work will soon be published]), or the unexpected linkage (through soil pH) of invasive Garlic Mustard (Alliaria petiolata) and the tiny arthopods known as springtails (Collembola), brought to us by Anne Alerding of Virginia Military Institute.

For me, the most interesting talk (and most challenging to follow along with) was Karen Barnard-Kubow‘s explication of her dissertation research on the genetics of American Bellflower (Campanulastrum americanum). This species has a range from the Virginia Coastal Plain to the breadbasket Midwest. Barnard-Kubow’s work has identified distinct clades: one in the East, one or two in the Appalachian Mountains, and one in the Midwest. Cross-breeding experiments on these populations suggests that the plant might be in the process of speciation. Her work also indicates that genetic material in the plant’s chloroplasts is sometimes inherited from the male parent, rather than strictly from the female, as received wisdom has it.

Some links: 71

Catching up on a lot of bookmarks, so this will be a bit of a link dump.

  • Reduced-meat or meatless diets (Mediterranean, pescetarian, vegetarian) are both better for your health and more sustainable for the environment, as David Tilman and Michael Clark find in a recent paper, and as Elke Stehfest summarizes.
  • I am loving Nature‘s new sharing tools. Susannah Locke explains the journal’s move toward more open access.
  • Emily Dreyfuss signed up to give Wikipedia six bucks a month.

    …Wikipedia is the best approximation of a complete account of knowledge we’ve ever seen.

    It’s also the most robust. The most easily accessed. And the safest. It exists on servers around the world so, unlike the library at Alexandria, it can’t be burned down.

    You should chip in, too. kottke.org

  • The Biodiversity Heritage Library has opened an online exhibit dedicated to women in science who began working before 1922. Some of my recent subjects are there, including Florence Merriam Bailey and Mabel Osgood Wright.