Wednesday, 29 April 2015

Bringing back the Brontosaurus: Why taxonomy is cooler than you think

Taxonomy is not a popular field of science. In fact, it’s a safe bet that most of you just switched off a little because I started the article with an unfamiliar, boring sounding word – why would you put the word “tax” in anything you wanted people to care about? Taxonomy (sorry) is the discipline that categorizes the living world. People who devote their lives to this field comb over samples of bugs, bones and botanical wonders and ask the perplexing and often difficult to answer question: What is this thing? Unfortunately, the world is in the midst of a woeful shortage of taxonomists, meaning that countless species don’t have anyone to give them the limelight they deserve.

Just like any other area where knowledge is the end-game, taxonomy can be interesting if you think about it in the right terms. We live in a world that has largely been explored. We've been to space and pretty much confirmed that all the major land masses on the planet have been discovered. We don’t know much about the bottom of the ocean, true; but few of us have spare submarines lying around or the licenses to pilot them. Taxonomists, on the other hand, still get to explore. Every day they venture into the archives and try to find new creatures. On a really good day a taxonomist might even get to name something after themselves.

Finding a new kind of animal is probably easier than you imagine. Life on earth is so ridiculously diverse and complex that conservative estimates suggest that 75% of everything that lives on this planet has yet to be described. Even in Europe, a place that has been pretty thoroughly picked over, amateur taxonomists discover new plants and animals at a rate that contributes significantly to the 16,000 new papers that are published each year describing something previously unknown. Go flip over a rock or shake a tree and the odds are reasonable that something that falls out might be unknown to science… There’s just a ridiculous amount of stuff out there.

Occasionally though, we find something new right under our noses. It might even be something that we've been staring at for well over a century, but one day something clicks and we begin to see it differently. Recently that very thing happened in the field of paleontology, and we can all get excited about the details.

You may remember back in Sketchy Fact #69 we declared “Brontosaurus never actually existed. It was the product of mistakes made during the initial rush to discover as many dinosaurs as possible and putting skeletons together incorrectly.” And while that may have been true at the time, researchers have since discovered that the initial mistakes may in fact have been mistakes themselves.

Researchers across Europe have been pouring over the bones of 81 individual dinosaurs for the past few years, comparing them in every conceivable way. For over 100 years the specimen that was originally called a Brontosaurus has been reclassified as a different species of a similar-looking group of long-necked dinosaurs called Apatosaurus. As the researchers examined bone after bone, they found that most of the time the names given to specific animals fit pretty well; however, when they looked at the very first Brontosaurus specimen they discovered some previously overlooked differences from Apatosaurus that they decided warranted it being called something else. The main difference was that Brontosaurus had a more slender neck than Apatosaurus. Ironic, given that Brontosaurus translates to “thunder lizard.”

It may seem like semantics but bringing back the Brontosaurus is on par with calling Pluto a planet again. This was a totally unexpected discovery that took over a century for someone to make. It just goes to show that wherever you look in this crazy world of ours, there are discoveries to be made. What better reason could there be for all of us to roll up our sleeves and put on our taxonomy hats? 

Friday, 24 April 2015

Sketchy Fact #88: Jupit-Hurl

Despite being the largest planet in our solar system, Jupiter has a shortest day. It spins on its axis once every 9 hours and 55 minutes.

Wednesday, 22 April 2015

The Non-Cheese Hypothesis: Where did the moon actually come from?

The moon is a frustrating reminder of the insignificance of the human race. Most every night we can look up, glimpse this celestial body and see enough detail to be reminded that there is a whole lot of amazing stuff going on in the universe that we can only experience on the most superficial level. The moon appears so damn close, but in reality is near the limits of our ability to explore. It took the combined efforts of the world’s two superpowers over 2 decades in the mid-twentieth century using all their resources and know-how just to get a few guys onto to moon’s surface and bring back some rocks. Generally speaking, the moon confounds us.

Nowhere is our confounditude better represented than in the simplest question that pops into a person’s mind when they sit and stare up at the shape-shifting orb in the night sky: where the hell did that thing come from? When we are kids we get all kinds of hair-brained explanations from story books and our parents that amount to a collective shoulder-shrug via their implausibility. I mean, come on, made of cheese? Are there cows in space I don’t know about or have we been ejecting sub-par dairy into orbit for the past couple thousand years?

The truth is, we would walk on the the moon's surface, orbit it a bunch of times and listen to ‘Beat It’ before scientists had a generally agreed upon theory of where the moon actually came from. It wasn’t until a conference in Hawaii in 1984 that two papers written nearly ten years earlier became accepted as sound science. Each pronounced that the moon was the result of an impact between the Earth and some other object. But this impact is like nothing we can remotely imagine. It makes the impact that ended the age of the dinosaurs look like a planetary bonk on the head. The impact that gave us the moon, to follow the comparison through, would have been like crashing a motorcycle into a wood-chipper.

Around 4.6 billion years ago – or so the story goes – the Earth was minding its own business, spinning on its axis and orbiting the sun, as planets do. Then seemingly out of nowhere, a spunky upstart proto-planet called Theia – presumably doing the planetary equivalent of texting while driving – absent-mindedly smashed into the Earth.

The collision completely fractured and melted the surface of both planets and flung material into the surrounding space. Fortunately for us, Theia was only about 10% the size of the Earth (roughly the size of Mars) so the Earth was able to pull itself mostly back together. The leftover material came together and began drifting around our planet and eventually became the moon, but for a few thousand years an Earthbound view of the night sky would have been a decidedly more dramatic experience with rocks the size of mountains smashing into each other and recombining constantly.

As elegant and awesome as this theory is, it took until April 2015 for it to get the evidence really needed to support it. Indeed, earlier this month three papers were published that provided much-needed corroboration for the giant impact hypothesis.

The first explained why the Earth and the moon are so similar. See, if the moon was the result of another planet smashing into the Earth we would expect it to be made of profoundly different material… but it isn’t. Researchers now explain this with new evidence suggesting that objects that form in proximate parts of the solar system are made of strikingly similar stuff. It appears Theia may have been a chemical baby brother to the Earth rather than a real alien.

The other two papers, oddly enough, support the impact hypothesis by explaining why the moon is different from the Earth. The first, published in 2014, found that the proportion of the element Tungsten in the moon's crust is greater than in the Earth’s. The second paper, published this month, explains this difference by suggesting that the amount of Tungsten in the Earth and the moon was roughly equal immediately after the collision with Theia; but the Earth, which is much bigger than the moon, attracted more asteroid and comet impacts in the meantime and thus added more material to dilute the amount Tungsten relative to the rest of the planet.

So that is where we stand. We finally feel like we know a very basic thing about the space rock we have been staring at since the dawn of time. Fine work humanity. Better late than never.

Friday, 17 April 2015

Sketchy Fact #87: Moon Face

Unless you’re an astronaut you will only ever see one side of the moon because it rotates the Earth at the same speed that it is spinning.

Wednesday, 15 April 2015

Medieval Medicine: Fighting Modern Infections with Long-Lost Potions

Looking back at the history of medicine is usually an exercise in presentism. It is supremely interesting and plenty of fun to learn about the things that people used to think were medical problems (like hysterical, disobedient women) and the treatments they came up with to treat them (eye of newt, anyone?). The problem with presentism is that we assume modern medicine is better than what came before it, but the truth is, ancient doctors sometimes knew things that we have since forgotten. Just as ancient cultures were often better as sustainably making use of the environment than we are now, it should be no surprise that they were skillful at treating what ailed them.

A perfect example of ancient acumen popped up earlier this month in science news columns around the world as researchers and historians at the University of Nottingham in the UK cooked up an ancient brew to combat an infection that even modern meds have trouble fighting.

“Take cropleek and garlic, of both equal quantities, pound them well together… take wine and bullocks gall, mix with the leek… let it stand nine days in the brass vessel…” read the 1,000 year-old Anglo-Saxon text from which they pulled the recipe. The potion was used to treat “stye,” otherwise known as an infected eyelash follicle.

The bacteria at the heart of the infection is known today as methicillin-resistant Staphylococcus aureus (MRSA). The key thing to note in that name is “methicillin-resistant,” meaning that the bacteria are of the sort that we learned about last year in our semi-fictional story about Curious Geoff and the Antibiotic-Resistant Superbug. So if our most powerful antibiotics today have a tough time with MRSA, how did the ancient remedy fair?

As you might have guessed based on the existence of this article, the answer is pretty damn well. It should be noted that the researchers needed to make a few modern revisions to the recipe. Garlic and leeks have changed a lot since the 9th century and brass vessels are both expensive and difficult to keep sterile (the researchers ended up using glass bottles with pieces of brass immersed in the other ingredients). In the end, however, the tweaks didn’t seem to reduce the effectiveness of their medieval gunk. The concoction killed 90% of MRSA bacteria, the same proportion as the conventional treatment that doctors use today to treat infections, called Vancomycin.

This isn’t the first time we have rediscovered an ancient medical treatment that rivals modern scientific wizardry. Artemisinin, a potent drug in the treatment of malaria was discovered by the Chinese military in the 1970's as they combed through ancient texts looking for treatments they could use to keep their Vietnamese allies healthy as they fought a war with the US.  We also still use leeches to help relieve patients of infected blood. What this most recent discovery means, however, is that we might be able to pinpoint why it kills resistant bacteria and use that knowledge to develop treatments for other antibiotic-resistant infections.

As bacteria continue to evolve resistance to our best treatments, we will need all the help we can get. Some of the answers will likely come from nature as get better at making use of plants, soil bacteria, fungi, etc. But as counterintuitive as it might seem as we ponder the future of medicine, it occasionally pays to look deep into the past. You never know what you might discover if you keep an open mind.

Wednesday, 1 April 2015

Indecisive Evolution: Where did whales come from?

It is tempting to think of evolution as a linear process. You start with some primitive creature like an amoeba or a slug and over time you get rid of the slime, add some legs, maybe a bit of fur and you’re on your way to something more advanced. Unfortunately this is utterly and completely false. Natural history is full of examples of animals that just don’t change no matter how much time you give them. Crocodiles and sharks are two well-known examples but the clad of stubborn animals also includes horseshoe crabs, dragonflies, coelacanths and nautiluses just to name a few. Other animals oppose the idea of straight-line evolution in an entirely different way: they change, and then change their minds about changing.

It is strange to think that over millions of years a line of animals can commit to a new way of life, slowly accumulate the necessary genetic changes to become better and better at it, and then totally cut their losses and try to go back to what they used to be, but it happens all the time. The best example of the evolutionary yo-yo effect comes from everyone’s favourite paradoxes of the natural world, marine mammals.

The story of how we got whales, dolphins, seals and the like is a supremely interesting one that spans the entire history of life on earth. Actually, “interesting” is sort of in the eye of the beholder on this one because things kick off with the evolution of single-celled life around 3.6 billion years ago and then not much happens for about 3 billion years. After that, things got downright exciting, though. Multicellular marine life came onto the scene around 555 million years ago; the ancestors of scorpions, spiders; and millipedes took to the land 100 million years after that; land plants soon followed around 420 million years ago; and then, fashionably late to the land-dwelling party, four-limbed vertebrates crawled out of the ocean around 360 million years ago.

This last group is the one we are interested in. The animals that evolved from these air-breathing pseudo-fish became reptiles, dinosaurs, and all the mammals that have ever lived, including us (humans) and – perplexingly – marine mammals. Mammals as a group really came into our own in the dust of a global catastrophe around 65 million years ago. A massive object from space had just paid an unwelcome visit to Earth and wiped out the dominant creatures of the time, who we now know as dinosaurs. From the rubble of that world crawled a small, shrew-like animal that is the last common relative of everything from bats, to humans, to whales.

Lineages diverged and new species evolved for around 15 million years until around 50 million years ago a rebellious creature known to scientists by the name of Pakicetus decided it wanted to change things up. Pakicetus was an interesting animal. Imagine a wolf with an elongated head and hooves and you aren’t far off. We believe that they hunted animals both in an out of the water on the edges of oceans, because over time Pakicetus gave rise to other species that were more well-equipped for life in the water. Gradually the offspring of Pakicetus developed a longer tail and more hydrodynamic shape along with limbs better able to propel it through the water.

Over many generations these slight changes became more and more dramatic. The nasal passages moved up to the top of the head to allow for easier breathing at the surface, the tail became the primary means of propulsion to the extent that hind legs were only in the way and eventually shrunk down to basically nothing. These adaptations were incredibly successful and allowed this line of animals to grow into the largest animals that have ever lived on this planet: modern whales – as well as their smaller cousins, dolphins and porpoises.

Surprisingly, it only took about 10 million years to turn Pakicetus into the first recognizable whale (Dorudon), demonstrating that abandoning one way of life for another isn’t all that challenging for natural selection. If you want a snapshot of the midway point along this evolutionary line, take a look at seals, sea lions and otters.

Obviously, evolution’s work is never done. In spite of how well adapted these animals now are for life in the ocean, they still need to come to the surface to breath. Over time (a lot of time) that might change, or maybe they will transition back onto land as turtles and tortoises have done a number of times over the past many millions of years. All we know for sure, is that evolution plays by it’s own rules.