Algae having a par-tay today. It's nothing compared to the 5-million year bender they went on 250 million years ago. Creative Commons eutrophication&hypoxia

About 250 million years ago in what is today the vast backwater of north central Siberia, the Earth coughed forth an unimaginable quantity of lava over the course of 1 million years. The liquid rock was a low-viscosity, thin stuff (for lava), so instead of forming a field of towering volcanoes it oozed out into endless plains. Covering some 1.5 million square kilometers today (600,000 square miles — something like the surface area of Europe), the beds may have originally covered 7 million square kilometers and taken up 1 to 4 million cubic kilometers in volume.

Scientists still do not agree why this happened, although it has happened many times before and since around the world. But they do agree on the timing: it happened at the same time as the Great Dying — during the Permo-Triassic extinction just prior to the age of dinosaurs that wiped out more life on Earth than any other, including the one with the giant asteroid with our name on it.

Not all scientists agree that the Siberan Traps, as they are called (trap comes from the Swedish word for “stairs”, which is how the frozen lavas can appear today) chiefly caused the extinctions. But many do, and it seems to be solidifying (er, pardon the pun) as the majority opinion.

What is also known is that life took some time to recover from this cataclysm. For at least 5 million years after, we can find little in the fossil record. Scientists have wondered whether this was a case of too much or too little food.

How, you might ask, could too much be a problem? Well, visit your nearest pond contaminated by fertilizers from lawns, golf courses, or farms and you will see: vast swarms of algae, that hog all the oxygen and choke out “higher” forms of life like fish. Or, for that matter, the New-Jersey-sized Dead Zone in the Gulf of Mexico, which formed in response to the endless streams of fertilizer runoff from farms pumped into the sea by the Missouri, Mississippi, and Ohio River system. We call this eutrophication*, and now, the authors of a paper in in Earth and Planetary Science Letters are pretty sure it is what prevented most life from recovering for those five million long years.

What happens when the party gets a little too wild. A lake in China with rampant eutrophication. Creative Commons eutrophication&hypoxia

How might scientists figure this out? As it turns out, one of the enzymes that catalyzes photosynthesis has a quirk. Thinking back to high-school chemistry, recall that the nucleus of an atom is made of protons and neutrons. Different elements are defined by the number of protons their nuclei contain. Carbon *always* has six protons. If it had seven, it would be nitrogen. But elements can vary in the number of neutrons they have. Carbon, for instance, can commonly have six neutrons or seven. Carbon-12 represents the former, while carbon-13 the latter.

As it happens, one of the chief enzymes of photosynthesis — RuBisCO, the one responsible for grabbing carbon dioxide from air and setting it on the path to become glucose — processes carbon dioxide containing carbon-12 a little faster than carbon dioxide containing carbon-13. Over jillions of cycles, the difference accumulates, and life becomes enriched in carbon-12. It makes little or no difference to the organisms themselves.

But it makes a big difference to scientists, who can use this knowledge to tell how fast the oceanic biological pump — the transfer of carbon from the atmosphere and surface waters to the seabed by microorganisms that live, die, and sink — is churning. The more these microbes nom, the more carbon-12 builds up in preference to carbon-13 in seabed deposits, where marine algae sink, store carbon, and are eventually pressed into limestone after they die. Scientists who studied marine deposits recorded in Chinese rocks during this 5-million year gap have found the carbon-12 enrichment is about double what exists today. If life had starved after the Traps did their dirty work, they would expect to see the opposite.

This is the scenario the authors of this new paper believe may have happened: as they erupted, the Siberian Trap lavas and the rocks they metamorphosed by contact spewed carbon dioxide (as well as many other volcanic gases) into the atmosphere. This warmed the atmosphere, which increased the evaporation of water, itself a greenhouse gas, perpetuating the cycle.

At the same time, more water vapor produced more rain, which weathered the land quickly. All that runoff drove incredible quantities of phosphate — a nutrient that limits the rate at which marine algae can grow — into the ocean. With a new all-you-can-eat buffet of phosphate and carbon dioxide at their disposal, marine microbes went nuts. The ocean was stripped of free oxygen, preventing any animal life that had managed to survive the extinction itself from regaining ground. Once the initial trauma of the Permo-Triassic extinction was over, these algae must have bloomed in quantities unimaginable. What is now the Blue Planet, and once may have been the White Planet, was briefly, it seems, the Green Planet.

What finally stopped the madness (from our perspective as vertebrates), was the waning of the volcanoes. Eventually, carbon dioxide levels dropped, and warming and rainfall decreased. With less erosion, oceanic phosphate and nitrogen concentrations dropped. Without enough of these nutrients to go around, algal numbers shrank, leaving enough oxygen around for other forms of life to exploit. And, luckily for us, they did.
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* Which is the reason you should all be using phosphate-free detergents.

Meyer, K., Yu, M., Jost, A., Kelley, B., & Payne, J. (2011). δ13C evidence that high primary productivity delayed recovery from end-Permian mass extinction Earth and Planetary Science Letters, 302 (3-4), 378-384 DOI: 10.1016/j.epsl.2010.12.033

The Cocoon. Creative Commons raindog

Note: Clarification appended

It’s not fair to review an entity one has not experienced oneself. But since the new Darwin Centre of London’s formidable Natural History Museum is in, well, London, and I am demonstrably not, nor easily got there short of a $1000 plane ticket (and I don’t expect the NHM’s going to comp me, especially after this review), I am reduced to reviewing by proxy: through the New York Times review, and my impressions thereof.

If you are not familiar with the newly opened Cocoon at the Darwin Centre, take a mosey on over to the NYT and so so here. Or check out the Darwin Centre’s web site here. In short, the Darwin Centre is the Natural History Museum’s attempt to put the museum and what it does on display in a thoroughly modern way*. Out with Victoriana, in with touch screeniana.

My chief complaint about the Darwin Centre, and its cousins like this exhibit on biodiversity at the Exploratorium in San Francisco, is that they continue the trend of ascepticizing natural history and self-gratifyingly focusing on scientists rather than the real show — the ORGANISMS.

As the New York Times says,

The research facilities and scientists are part of the exhibition; they are glimpsed through windows, framed by explanations. They even become the subject of the show. The Cocoon’s displays are not really about botany and bugs; they are about the collection and study of botany and bugs. The exhibition is really about the museum itself — its methods and materials, its passions and enterprise. I don’t know of another science museum that does this. Along the way, of course, you learn about the natural world, but the real focus is on how that world is studied, and how the museum pursues that goal.

I don’t want to paint the good folk at the NHM in a negative light. I’m sure the designers of this exhibit spent countless hours thinking it through and poring over what way they could best reach the public. They want to teach evolution, the scientific method, and how modern taxonomy works; they want to bring science to life by showing scientists in action. They were given a goal and a budget, and they did their best. I just don’t agree with the goal.

Or rather, that putting this information on display is as important or as interesting and appealing to the public as some other goals. Would you rather go to this exhibit with your child, or one about slime molds or diatoms?  In short, what bothers me most about this exhibit, and the one in San Francisco, is what they seem to say about where biological natural history education is headed. All the effort they put into this exhibit could have been put into making the world’s first Hall of Protists, or Plant Evolution Gallery, or a Bacteria and Archaea Family Album. Instead, we get swipe cards, video guides, sorting games, and generalities — and a rather narrow view of nature. Butterflies, insects, and flowers are great, but what about all the other stuff?

Personally, I find the products much more fascinating than the process. There should be a place to showcase all of them too, and not just the ones with backbones, shells, or exoskeletons. Because learning about the products, while inherently fascinating, almost always leads to questions about the process. After all, Darwin himself started there. He spent five years looking at products while aboard the Beagle.

When I write hear about yeast and their “lifestyles”, or about diatoms, or about pine pollen, or slime molds, or the sex lives of red algae, or about alien pelagic peanut creatures, I’m only scratching the tiniest surface of all the fantastic forms, creatures, structures, and lifestyles that I learned in school. And believe me when I say that *I* only scratched the surface of what’s out there. There is so much more: the fantastically beautiful filaments called slime mold elaters, for example. Hornworts. Nematode-trapping fungi. Where baby ferns come from (not adult ferns). Anglerfish and sea angels. Ping pong tree sponges. Archaea. Radiolarians. Camel spiders. Slime nets. A blizzard of protists and algae and all their mind boggling forms. These things are this blog’s raison d’etre: I want to show and tell you about them not only because I can barely contain my own excitement, but because almost no one else is, at least not in a way the general public can understand.

But I can tell you who should be: natural history museums. A few are trying. I’m particularly fond of the new Sant Ocean Hall at the Smithsonian, which I reviewed here last fall, and which makes an admirable attempt to convey biodiversity through pictures, specimens, and an armada of world-class fossils. I also quite like the evolution and fossils exhibit called “Prehistoric Journey” here in Colorado at the Denver Museum of Nature and Science. My memory is hazy, but I did visit the Hall of Biodiversity at the American Museum of Natural History in New York when it was new about 10 years ago, and I seem to recall it falls somewhere between the two extremes. And, I should note, the Natural History Museum in London itself has just begun what looks to be a fascinating new exhibit (again, I have no plane ticket) on Deep Sea Biodiversity.

I am also a *huge* fan of zoos, aquariums, and botanic gardens because they do such a good job of spotlighting the organisms, but often their signage falls short: it’s vague, confusing, overly technical, overly simplistic, or boring. It doesn’t help you make connections between organisms to understand common structures, interesting adaptations, the general features of a given group, relatedness — or evolution. And lets face it: fungi, protists, bacteria, archaea, microbes, algae, lichens and kin always get the shaft. There is no where you can go to see and learn about them and their forms and variety. But there should be, and as it stands, the natural history museums are the best existing place.

But they too struggle for funding, so it frustrates me that they now seem to be prioritizing and funneling what they do have toward this new once-removed tack toward natural history. Biodiversity and natural history as monolithic concept and scientific endeavor: scattershot, sterile, and boring. Only the choir will find that engaging. The cocoon, at least it seems to me, peering into it from 5,000 miles hence, insulates people from the real stars of the show — messy, wild, weird, surprising, and natural. If we truly hope to convince the world that saving these organisms from climate change and resource depletion is important (and it is, not just for their sake, but for our sake: preserving wildlife keeps the climate stable for agriculture and our water clean for drinking), we should shove the organisms themselves out on stage. All you have to do is take a closer look at them, and with suitably skilled and creative interpreters you’ll find, I think, they sell themselves.

* The Centre was also created to specifically house the botany and entomology collections, not any other groups. I apologize for the omission, but I didn’t realize this was the case until an alert reader pointed it out.

In my last post I discussed Carol Yoon’s recent article and book on the decline of taxonomy among scientists and the public. Taxonomy, which could easily be a dinner conversation subject and hobby for most of the 19th century (TR had quite extensive collections in his youth, for example), has virtually vanished among the general public today. This was brought to my own attention a few weeks ago, when I discovered a second grade primer published in 1897 on the desk of a colleague who collects old maps.

I opened and began skimming. The inside cover announced in spidery childhood cursive that the book had belonged to one Mildred Pennington, of Cuba, Ohio.

I looked up Cuba, Ohio on Google Maps and discovered it is nothing but the intersection of  a highway with one or two buildings now.

The first 16 pages were, unfortunately, missing. Here’s the copyright page and the first existing page of the text. The image should be familiar to every American . . .You Know Who is standing in the doorway watching.

The engravings that illustrated the text were astoundingly beautiful, and stories were an impressive assortment of “modern” tales, fairy tales, and fables. And there were two stories from ancient times, one set in Rome called “Androclus and the Lion”, and another set in Persia, called “Filling a Basket with Water”. Here is an engraving from the Persian story.

There also seemed to be a fair balance of stories calculated to appeal to either boys or girls.

But what struck me even more was the way natural history permeated the book. There was a story about a boy who nursed the broken wing of a bat he named Bobby, and stories on the natural history of bees and butterflies and the beaks of birds.

Finally, the elusive snipe is found!

And gloriously, On p. 20-22 in the margins were beautiful line engravings and the names of eight different species of oak (scarlet oak on last page not shown).

At the end of the story, the text asks the student, “Do you know how many kinds of oaks there are? Find as many kinds of acorns as you can. Find as many kinds of oak leaves as you can. Which kind of oak tree grows the tallest? Which kind bears the largest acorns? Which kind has the smoothest bark?”

Remember, this is a reading primer, not a biology or science book.

According to Yoon’s article, a two-year old child of the Tzetzal Maya people of Mexico can name 30 plants, and a four-year old, 100. How many can you name?

At the end of the book is this page. I thought you might like to see it too.

And being Victorians, they couldn’t help but embellish the back cover as well . . .