All this month, we've been telling you about a fantastic challenge from the Encyclopedia of Life. Called Armchair Taxonomist, it's an opportunity to research and write about different plants, animals, fungi, and microscopic organisms — and, in the process, help move scientific information from places where it's hard for most people to see, to an open-access sandbox on the Internet.

If you've taken the time to write up an entry, fantastic. We're looking forward to reading them. You've also got a shot at the great stuff up for grabs — including a private, behind the scenes tour of the Smithsonian's National Museum of Natural History. If you've not entered yet, though, this is the last weekend you can. The deadline is Monday, May 20th at 6:00 pm Eastern.

Read all about the Armchair Taxonomist challenge.

And be sure to check out the stories in BoingBoing's taxonomy series:
• Learn what leeches and ligers can teach us about evolution
• Meet the model animals against whom entire species are judged
• Find out what taxonomists and Mr. Spock have in common

National Geographic calls Ethiopia's Danakil Depression "the cruelest place on Earth." It's a desert wasteland, where temperatures can push past 120 F, where ancient and current lava flows impede movement, and where water is so scarce that that people build rock domes over the top of volcanic vents to trap and condense steam.

It's also a place where Ethiopian men and boys regularly travel in order to cut slabs of salt off of the surface of the Earth and haul them back to civilization. Salt flats like this occur when entire bodies of water totally evaporate. In the Danakil Depression, you'll also find salt towers and other formations caused by evaporation off of volcanic geysers and hot springs.

The photo above was taken by Reuters photographer Siegfried Modola, who traveled with a group of salt miners into the desert and then followed their haul all the way back to the marketplace. You can see his full slideshow of images online. I chose this one because it gives you a view of the salt as it's found on the ground, and the neat, rectangular blocks the merchants cut it into for shipping.

The spot is a favorite of photographers. I'd also recommend checking out the photos and story put together by Christina Feldt, who posted about the Danakil salt flats earlier this year.

Kiera Wilmot — the Florida 16-year-old who created a small explosion just outside her school before classes started by mixing cleaning solution and tin foil (she was just curious, nobody was harmed) — will not be charged with a felony, after all. Florida State Attorneys dropped the charges against Wilmot yesterday. After her case garnered national attention, she ended up with a lawyer who has defended her mostly for free. There's no word yet on whether she'll be allowed to return to the school that expelled her and pressed charges in the first place.

In the meantime, the Internet has created a nice happy ending here. Homer Hickam — the writer and former NASA engineer whose memoir is the basis of the movie October Sky — started a Crowdtilt campaign to send Wilmot and her twin sister Kayla to the Advanced Space Academy program at the U.S. Space Camp in Huntsville, Ala.. The cost of space camp can run upwards of $1200. Hickam paid for Kiera Wilmot to go and the Crowdtilt campaign raised the other $1200 for her sister, plus extra money for their travel expenses. The campaign hit its $2500 goal in just two days and is now up to $2920. Hickam says the extra money is going to the girls' mother.

A second Crowdtilt campaign raised more than $8000 for a Kiera Wilmot Defense Fund. Now that the charges have been dropped, that money will go into a trust, to pay the few legal expenses the family does have and to cover costs associated with Wilmot's education — especially since it's still unclear whether she'll be allowed back into the local public school.

Good job, Internet!

Apparently, there were some private citizens from the USSR who were allowed into the U.S. for travel during the Cold War. But they couldn't just visit anywhere they wanted.

This map, from a post at Slate's Vault blog, shows the no-go zones, shaded in green. Some of this is quite funny — gee, guys, I wonder what you're keeping hidden out in rural Nevada? Another interesting point: Soviets could visit Kansas City, Kansas, but not Kansas City, Missouri. Which could just be a pretty good joke, on our part. The fun stuff is all on the Missouri side.

EDIT: In the original version of this post, I'd mentioned that Kansas had once been home to many, many missile silos, and speculated that this might be why so much of that state (and the Dakotas) was off-limits to Soviet travelers. But, Cold War historian Audra J. Wolfe contacted me and pointed out that there were no missile silos at the time this map was made, because there were no Intercontinental Ballistic Missiles. So why ban the Ruskies from Kansas? Wolfe isn't entirely sure. She speculated that it might have had something to do with limiting access to public lands managed by the Bureau of Indian Affairs or the Bureau of Land Management. It also could have been tied to the presence of Strategic Air Command bases in the state. And there were tons of Atomic Energy Commission-owned sites scattered all over the U.S. — it's hard to keep track of where they all were.

Of course, Wolfe also said that there wasn't always a clear logic behind the decisions about which parts of the country were made off-limits to Soviet citizens. For instance, much of our coastline was off-limits for no other reason than the fact that much of the Soviet coast was off-limits to Americans. "The main premise is 'strict reciprocity'," she wrote in a message to me. "X% of Soviet coasts are off-limits, therefore x% of US coasts are off-limits, too." So there, one might add.

Thankfully, my personal food guru, Lynn Rosetto Kasper, is here to call shenanigans on all this nonsense. She gave a fantastic interview on MPR this afternoon, shooting down the idea that everyone would love to cook if they only tried it. In fact, says Kasper, you don't have a moral obligation to cook at all. The world needs eaters, too.

Tom Crann: What are some of the pressures, and why? Where do they come from, for people who feel pressured to cook if they're not very good at it?

Lynne Rosetto Kasper: The new food awareness that we've seen over the past decade. Here's the flip side. We cook if we are smart. We're supposed to cook to save our families and ourselves from dysfunctional, unhealthy lives. We cook to fight the obesity epidemic. We cook to save our identities, culturally, our traditions. We cook to strike out against the forces we feel are evil -- you name them. We cook because it shows how cool we are. ... the pressure today is we all should be doing this thing. And yeah, it's great to cook, it's wonderful to cook. But this is not something you take on if you really think you're going to hate it.

I think we should - if we possibly have an option -- do what we really enjoy doing. Because no matter what it is, that's what we're going to be good at.

You can read a transcript online, but it leaves out some of the discussion and I recommend listening to the audio. It's an interview of beauty. And I say that as somebody who loves to cook. The key, though, is that cooking every meal is not something I alone am solely responsible for, no matter how I'm feeling or what day it is. It's not something that takes up a large portion of my life. And it is something that I just happen to find relaxing and fun. If any of those facts weren't true, my thoughts on cooking might be very different. And it's silly to expect otherwise.

What happens inside a caterpillar's cocoon? Scientists got to watch the whole process with the help of X-ray 3D scanning technology. In the video above, you can watch a caterpillar turn into a butterfly. Over the course of 16 days its breathing tubes (shown in blue) and its digestive system (shown in red) change shape and position within the body, while other structures grow from scratch.

Ed Yong has a great story to go with this, too. All about why it's important to actually watch the process happening in a single caterpillar, instead of just relying on the data scientists have collected from years of dissecting different caterpillars at different stages in the transformation.

Artist Hiné Mizushima makes these super adorable models of microscopic crustaceans called Daphnia out of felt. Scientists like to get the real-world versions of these creatures drunk, and use them to study how alcohol affects the nervous system. I suspect that Daphnia are cute drunks.

Via David Ng

This is the third story in a multi-part series on taxonomy and speciation. It's meant to help you as you participate in Armchair Taxonomist — a challenge from the Encyclopedia of Life to bring scientific descriptions of animals, plants, and other living things out from behind paywalls and onto the Internet. Participants can earn cool prizes, so be sure to check it out! The deadline is May 20th

As depicted on Star Trek: The Original Series, the tricorder is a device that looks like the bastard love child of a Polaroid camera and a 1970s-era portable cassette deck. It was worn around the neck on a strap. It was black and clunky and definitely not what we would, today, call a sexy piece of electronics.

What made the tricorder a great piece of fictional technology wasn't its looks, but what it did. "Mr. Spock could use it to identify any organism, plant or animal, anywhere in the galaxy," said Carlos Garcia-Robledo, postdoctoral fellow in the department of botany at the Smithsonian's National Museum of Natural History. A portable tool that could quickly identify any species anywhere would be a game changer for science. Eventually, according to Garcia-Robledo and others, we'll have just that — put a piece of leaf or fur or insect leg into a machine and out pops its taxonomic information.

But what makes this really awesome is that — aside from the portable part — this is something we can actually do already. Garcia-Robledo does it regularly in his lab. The real-world tricorder isn't just something that's going to transform science someday. It's already doing that, right now.

The non-fictional tricorder is based on an idea called DNA barcoding, which originated in 2003 with Canadian biologist Paul Hebert. He thought there might be an easy way to quickly identify species using short DNA sequences that are unique to one species or another. If you had a database of these sequences, then all you'd have to do would be to match a sample to a sequence and you'd know what species you were looking at. It's similar to the way we store fingerprints, and then use those to match prints from a crime scene with an individual person.

Of course, like fingerprinting, DNA barcoding turns out to be more complicated than it sounds. The sequence most commonly used to barcode animals is a gene called CO1. It's a piece of mtDNA. This DNA is found inside the mitochondria — organelles within a cell that produce energy. It's there because, once upon a time, those mitochondria were independent bacteria, doing their own thing as single celled organisms. MtDNA doesn't create you, it creates parts of your cells.

The mitochondria, and their DNA, get passed down from generation to generation in egg cells — sperm don't usually have them. So you carry your mother's mtDNA. And she carries her mother's. But that mtDNA doesn't travel through the generations intact. Over time, it picks up little errors and changes to the sequence. This is where DNA barcoding — and its complications — come in.

Image: A room full of DNA sequencers, a Creative Commons Attribution (2.0) image from jurvetson's photostream

The idea is that the changes that happen to CO1 should be able to serve as a marker between species. In order for that to work, though, the mutation rate has to hit a sweet spot, said Karen James, a staff scientist at Mount Desert Island Biological Laboratory. She does a lot of work with DNA barcoding and described the ideal amount of variation in the DNA sequence as being a Goldilocks sort of problem. If you have too little variation (i.e., if the mtDNA doesn't change fast enough) then you'll have too many different species that share the same barcode. But if the mutations happen too quickly and you have too much variation, then you could get a bunch different barcodes within the same species. Either way, the barcode would be useless — just as if lots of people shared the same set of fingerprints.

The good news is that, for many animal species, CO1 hits that sweet spot. The bad news is that it doesn't work for everything. In fact, it doesn't work for plants at all. Their mtDNA changes too slowly. In 2009, James was part of a team that identified alternative DNA sequences that can be used to barcode plants.

CO1 also varies in how well it works for different kinds of animals. Like plants, mtDNA changes slowly in cnidarians — a phylum made up of more than 10,000 species, including many kinds of jellyfish. The plant sequences won't work for them, either, so cnidarians are notoriously difficult to barcode.

All of this explains part of why DNA barcoding can't really be used to identify new species. If you don't know the organism well enough to know how quickly its mtDNA are mutating, than you have no idea whether the changes you see represent a new species, or just variation within an old one. But that's okay, say researchers like Garcia and James. It doesn't mean DNA barcoding is useless. Think back to the tricorder, and what Mr. Spock actually did with it. He wasn't identifying new species. Instead, he was figuring out which previously-identified species lived on which planet.

Rolled leaf beetles. Carlos Garcia-Robledo pulled half-digested plant bits out of their stomachs and used the DNA from those samples to find out what the beetles were eating. Photo by Charles Staines.

DNA barcoding can be used, along with traditional taxonomy, to help identify new species. Paul Hebert demonstrated this in 2004, when he figured out that a single species of tropical butterfly was actually 10 species of tropical butterfly, cleverly masquerading as one. But naming new species and pinning them to a board really isn't what the tool is best at — and it's not the most interesting way to use it, either. Even though the tricorder of today currently takes up a space the size of a room, it's already being used to study the world far outside the lab.

For example, Carlos Garcia-Robledo uses DNA barcoding to study the relationships between beetles and the plants they eat. His team figured out how to extract plant DNA from a beetle's stomach. Compare that DNA to a barcode library, and you start to get a good idea of what different beetles in different places are chowing down on. That matters, because the beetle's diets are changing along with the climate. As habitats get hotter, some plants can't survive. So what happens to the beetles that eat them? Garcia-Robledo uses DNA barcoding to track those patterns of adaptation and extinction.

Turns out, DNA barcoding is very good at helping us answer questions of sustainability and environmental change. It's especially important in places where it would be really hard to understand biodiversity and species interaction simply by collecting and counting — like the oceans, for instance.

We know that things people do can affect ocean ecosystems. And we know that some parts of the ocean bear more of the brunt of this than others. In order to understand what those differences really mean for wildlife, Smithsonian invertebrate zoologist Allen Collins has started collecting samples of all the biodiversity in a plot of ocean — from bacteria to charismatic megafauna. DNA barcodes tell him exactly what species live there. He can go back and sample the same spot over time to see how the mix of species has changed. And he can compare those changes in places relatively untouched by humans to what's happening in areas that have a lot of human impact. What, exactly, does "human impact" mean for ocean animals? That's what he's going to find out.

There are even consumer applications. Earlier this year, the ocean advocacy group Oceana released a report showing that restaurants and grocery stores have a habit of selling customers one fish, but labeling it as another. In fact, 33% of the 1200 samples they took over two years were mislabeled. When you think you're buying red snapper, you're often actually buying much cheaper tilapia. The secret swaps can affect your health and they can also affect fish populations. All Oceana's data came from DNA barcoding, Karen James said.

So far, all of this relies on bringing the world back to the laboratory for testing. But the real, portable tricorder is inching closer. We often talk about the $1000 genome, in terms of being able to sequence the entire thing cheaply. But the same technology that's making that dream a reality also applies to the much easier and faster task of sequencing a small strand of genome — you just have to adapt the tools to the purpose of barcoding.

Last year, a company called Oxford Nanopore announced that it had developed a miniature genome sequencer that could plug into a laptop's USB port. The device, called the MinION, isn't the real-world portable tricorder. It's designed to sequence entire genomes, for one thing, which isn't really what DNA barcoders want. It's also a one-time-use tool that's expected to cost $900 a pop — if it ever makes it to the marketplace. But the MinION is a step in the right direction. Someday (and probably someday soon), scientists will be able to study changing ecosystems instantly, while they're standing in that ecosystem — just like Mr. Spock.

Samples of organisms that Allen Collins brought back to the laboratory from a research trip to Bali. Someday, he'll be able to skip this step.

PREVIOUSLY:
• What leeches and ligers can teach us about evolution
• In the leech library: Behind the scenes at the American Museum of Natural History
• Be an Armchair Taxonomist!: A challenge from The Encyclopedia of Life

This is a picture of a wave crashing on the New Jersey shore. It glows because of dinoflagellates — little, single-celled plants, animals, and bacteria that float around on the water, moving about with the help of long, moveable protein strands called flagella. Some dinoflagellates are bioluminescent; that is, chemical reactions inside their bodies produce light. The result is glowing oceans. Or, as maker Caleb Kraft recently discovered, the dinoflagellates also make for a soft blue nightlight with really nifty special effects.

You can watch Kraft's nightlight project at YouTube. It's pretty simple to do at home. At it's most basic, all you need to do is purchase some bioluminescent dinoflagellates online, keep them alive in your home, and give them a good shaking occasionally to trigger the chemical reaction.

A couple more helpful links:
• Where Kraft bought his dinoflagellates
• A guide to other dinoflagellate dealers, and to the care and feeding of unicellular organisms
• Researchers at the Scripps Institution of Oceanography who are studying dinoflagellate bioluminescence to better understand how it works and what role it plays in the ecosystem
• A detailed explanation of what dinoflagellates are and why they glow

Via Treehugger

I was a judge on this year's Science Seeker Awards, which honor great science writing being done online. The winners were just announced and you should really check out the whole list. It's full of great writing, including some names and blogs you've probably never read before.

I also want to draw your attention to a runner-up post that made a big impact on me. It's a piece by Jalees Rehman about what happens when scientists (and science journalists) settle for easy work and quick rewards instead of pushing themselves. The post introduced me to the concept of der innere Schweinehund, aka "the inner swine-dog", a fantastic German metaphor for the part of ourselves that prefers laziness over productivity, comfort over challenge, and routine over achievement. Everything is a battle against our own inner swine dog. It's a terribly German way of looking at things, but it resonated with me — and will probably resonate with anyone who has ever had to decide between checking Facebook and finishing an important task.

More importantly, reading about it in the midst of judging some really good science writing reminded me of how important that daily battle is. These Science Seeker Award Winning stories will educate you, scratch your itch for curiosity, and help you question your world. Those are incredibly important goals, and the only way we reach them is by fighting off the inner swine-dog.

There is a statue of the Innere Schweinehund in Bonn. Norbert Schnitzler took this photo of it for Wikimedia Commons.

At an age when some people are struggling with their own memories (and many others are just plain dead) neuroscientist Brenda Milner does an amazing job of explaining her contributions to our understanding of how memory works. Milner is one of the researchers who worked with H.M., the famous patient who lost his ability to form new memories after undergoing brain surgery.

This is a long talk — almost an hour — but it's a fascinating look at the career of a scientist who changed the way we think about the mind, told in her own words.

You can watch the full video at Vimeo

I've seen this video described as a musical depiction of all the nuclear bombs ever detonated. But that sort of makes it sound like you're about to get a particularly bombastic version of the 1812 Overture. Instead, "1945-1998" by Isao Hashimoto is more like an infographic with sound effects — or, possibly, a mash-up of the games Simon and Global Thermonuclear War.

What you get is an interesting depiction of nuclear tests through time — 2053 of them (including the non-test explosions at Hiroshima and Nagasaki). I found it particularly interesting to watch the slow ramp up over the course of the late 1940s and early 1950s, when months or years would tick by between tests. After that, beginning in the late 1950s, you see these patterns of sudden flurries of explosions, usually happening in the US and the USSR almost simultaneously. The cultural sense of panic is almost palpable.