Category: Natural Sciences

Some links: 103

Some links: 100

  • Walter Shawlee, slipstick reseller, has passed.

    Over time, his customers included a weather station in Antarctica, where many electronic gadgets could not take the cold; photo editors responsible for adjusting image sizes (they like slide rules for their clear displays of different values for the same ratio); an archaeologist who found that calculators got too dusty to work properly during digs; the drug company Pfizer, which gave away slide rules as gifts during a trade show; slide rule enthusiasts in Afghanistan and French Polynesia; and “guys from NASA,” Mr. Shawlee told Engineering Times in 2000.

  • Sorry, overwintering turtles don’t breathe through their butts.

    The notion that cloacal gas exchange helps North American turtles survive long winters trapped under the ice is pervasive in pop science, but to date, there is no solid evidence that hidden-necked turtles use cloacal gas exchange. The skin and mouth lining are where gas exchange happens during winter hibernation.

  • The Old English for spider is gange-wæfre (“walker-weaver”).
  • From Zack Stanton for McSweeney’s, “Morrissey or Trump?”

    This could only happen to me / Who has been through anything like this?

  • Guest column for Washington Business Journal by Alan Berube and Tracy Hadden Loh: “Caps and Wizards moving to Virginia isn’t ‘regionalism.’ It’s gaslighting.”

Some links: 98

Some links: 92

  • Ted Williams puts in a good word for—euyurrgh—sea lampreys.

    In their native habitat, marine lampreys are “keystone species” supporting vast aquatic and terrestrial ecosystems….

    Environmental consultant Stephen Gephard, formerly Connecticut’s anadromous-fish chief, calls lampreys “environmental engineers” as important to native ecosystems as beavers.

  • Rhitu Chatterjee reports on a low tech-low cost (less than two bucks) intervention that can dramatically reduce maternal deaths due to postpartum hemorrhage.
  • May Truong’s photos, Sarah Lyall’s words: Striker, the Samoyed who never won Westminster’s best in show. But he still pauses to strike a pose.
  • This is why I leave little notes: T. Rex reckons with the afterlife.
  • One more bit of the hot type era is gone: the New York Times is dispensing with datelines. Hanaa’ Tameez has the writeup.

Some links: 91

  • Mr. and Mrs. Pickles have three baby tortoises! Cuter than cute.
  • They were gone before I knew what to call them: David W. Dunlap of The New York Times remembers reader ads.
  • “I can’t define it, but I’m against it.” Also from the Times, Nate Cohn attempts a definition of woke and what it portends.

    … much of what woke is grasping toward: a word to describe a new brand of righteous, identity-conscious, new left activists eager to tackle oppression, including in everyday life and even at the expense of some liberal values.

    * * *

    In the most extreme case for Democrats, the backlash against the new left could end in a repeat of how New Left politics in the 1960s facilitated the marriage of neoconservatives and the religious right in the 1970s. Back then, opposition to the counterculture helped unify Republicans against a new class of highly educated liberals, allowing Southern opponents of civil rights to join old-school liberal intellectuals who opposed Communism and grew skeptical of the Great Society. The parallels are imperfect, but striking.

  • Isobel Novick stans webbing clothes moths (Tineola bisselliella).

    These moths, unfortunately for those with infestations, have other behaviors that contribute to their indestructibility. They can metabolize their own water as a byproduct of keratin digestion, so access to water is not a dealbreaker for survival. What kind of organism can create its own water? This moth has evolved to be an efficient, dynamic, super-survival machine. They are incredibly temperature tolerant, with the ability to survive as eggs or larvae for several days at broiling temperatures as high as 95 degrees F and as far below freezing as 5 degrees F. They are attracted to the smell of woolens, and once established, send pheromonal signals to nearby moths to invite them to party. To add to their tank-like nature, webbing clothes moths can digest toxic metals like arsenic, mercury, and lead. They have no problem metabolizing synthetic materials or chewing through soft plastics. They have even been found on mummified human remains and have been around long enough to be mentioned in the Bible.

  • 17th-18th century tomfoolery: dummy boards.

5 takeways: 1

…from Nature Forward’s introductory class in lichens of Maryland, taught by Natalie Howe, in the NHFS program. (Without the goofy puns.)

1. Most naturalists understand a lichen to be a symbiosis between a fungus and a photosynthetic organism, either an alga or a cyanobacterium. The fungus provides water and protection for the photosymbiont. Typically, in a structure called a thallus, the photosymbiont is sandwiched between layers of the fungus (the mycobiont)—sort of like a lasagna. In turn, the fungus receives sugars produced by the cyanobacterium or alga.

But the association may be much more complex, with other types of organisms participating. These can include secondary algae, non-photosynthetic bacteria, yeasts, protists, and viruses. On the lichen’s surface, the role of microinvertebrates like tardigrades and nematodes is being explored.

So, what is a fungus? Your answer might depend on whether you see the duck or the rabbit. Trevor Goward, in a brief paper in Evansia, writes,

Next time you pause to contemplate a lichen, consider the strong likelihood that whatever it is you see staring back at you – fungus, alga, thallus, parasitism, mutualism, agriculture, gall, growth chamber, or farmstead – in some way reflects the particular mindset you bring to it; that what you’re looking at is really a face in the mirror; and that the face in the mirror is very much your own.

2. In many cases, you’ll have to be content with an identification to genus, especially in the field. The identification keys often depend on

  • testing the chemistry of the lichen, either with reagents like KOH and phenylenediamine,
  • examining spores with a microscope,
  • or performing TLC (thin-layer chromatography) back in the lab.

Just to make things more complicated, the bushy “reindeer lichens” that you may have seen growing on soil, formerly in the genus Cladina, are now in the very diverse genus Cladonia, which includes various organisms named pixie cup, British soldiers, and powderhorn lichens. Cladonia gets its own key in the guides.

All that said, you can usually make an ID limited to a group of a few species, and often use geography and habitat to reduce your choices even more.

Even if you don’t intend to make a field ID, break out your hand lens (you did bring your hand lens, right?) to examine the tiny cilia on a Parmotrema ruffle lichen, the minute lobes of Candleflame Lichen (Candelaria concolor), and the wee horns of Cladonia ochrochlora.

3. Studying lichens in the field is great if you like buying new gear, like a macro lens for your SLR, or a flashlight that throws ultraviolet light. Lichens in the genus Pyxine are drab gray in visible light, but they light up in brilliant yellow under UV. Somewhat like green plants that show red in their basal rosettes, lichens that reflect UV light do so to avoid being scorched by too much light.

4. With your eye this close to the substrate, you’ll meet lichen-adjacent organisms. Mosses growing on soil can provide a moist microhabitat for lichens; myxomycetes are doing their own thing; liverworts like Frullania sp. growing on tree bark might fool you; certain fungi are lichen parasites; and then there are ordinary “non-lichenized” fungi doing what they usually do, decomposing.

5. Natalie describes the lichen community as the “quiet Lorax.” Despite what we know about many lichen species’ sensitivity to air pollution (SO2, NH3, NOx, and O3), only two species are listed under the Endangered Species Act (Cetradonia linearis and Cladonia perforata). Perhaps more surprising, no non-lichenized fungi are listed. The United States does not maintain a nationwide Red List for fungi.

Field trip and workshop resources in the DMV

Here’s a roundup, somewhat Northern Virginia-inflected, of some organizations that run field trips in the mid-Atlantic.

Nature Forward is our standard-bearer. Workshops and camps for kiddos and families, walks focused on birds/geology/botany/etc., CEU-credited courses in lichens/spring wildflowers/conservation history/etc., overseas travel—something for everyone at nearly every level of expertise. NF is also an important advocate for protection of natural areas in the DC metro.

Some outfits mostly interested in birds:

Are you ready for some botany?

Maybe something a little more niche is your interest.

Or you’re looking for something more fast-paced than the naturalist’s shuffle.

The Washington metro is a mosaic of publicly-accessible, natural areas under several different jurisdictions. Check out individual parks and recreational areas for scheduled workshops, camps, and events.

*I know these organizations only by referral/search, not by firsthand field trip experience.

Wherein my illusions are dashed

Andy Brunning presents an infographic of the Mohs Hardness Scale, something I learned about when I was a squirt and received a student’s geology kit and have subsequently forgotten about. But behind that tidy 0-to-10 scale is a dirty little secret:

There’s no fixed value of hardness between the different numbers in the scale — in fact, diamond at 10 is several times harder than corundum at 9, but corundum is only around twice as hard as topaz at 8.

Germination

A little bit pitch drop experiment, a little bit Michael Apted, a little bit genetic repository: William Beal’s 142-year-old seed viability experiment, reported by Nell Greenfieldboyce.

A microbiologist named Richard Lenski looked on. “The others were digging and trying to figure everything out, and I sort of held the map and held it under my jacket to keep it dry at one point. That was my hard work,” says Lenski. “I was wondering if cops might show up at some point.”