The Anniversary of Silent Spring

By Claire Eamer

Rachel Carson in 1944.
U.S. Fish and Wildlife Service photo

This week marks an important anniversary. Fifty years ago yesterday - September 27, 1962 - was the official publication date of Rachel Carson’s book, Silent Spring. It was a ground-breaking, impeccably researched, and lyrically written chronicle of the damage being done to the environment by excessive use of synthetic chemicals, especially DDT. And it’s generally credited with launching the environmental movement.

Even before Silent Spring reached bookstore shelves, its friends and foes were lining up to do battle. The book had been serialized in the New Yorker magazine over the previous summer, so its contents were no secret. One of the big chemical companies threatened a lawsuit in an attempt to block publication, but Carson’s publishers went ahead anyway. With thousands of pre-orders and a spot on the Book of the Month Club roster, Silent Spring was heading for the best-seller list.

And Rachel Carson was heading into battle. She was an unlikely environmental warrior. Born in 1907, Carson was a biologist who had worked for the United States government until her successful books about the ocean made it possible for her to quit and write full-time. She was a quiet, private person who had worked hard all her life, supporting her parents, sisters, nieces, and an adopted son. Walks along the seashore and peaceful hours of writing were what she wanted – not a public platform.

Rachel Carson and Bob Hines conduct marine biology
research in Florida, 1952.
U.S. Fish and Wildlife photo

But the public platform is what she got. As soon as the book appeared, it was attacked by spokesmen for the big, powerful chemical companies, by agriculture departments, by scientists who had tied their reputations to the chemical revolution of the 40s and 50s, and by a lot of politicians who knew where their campaign funds came from. The problem facing her opponents, however, was that Carson had done her homework. Her research was solid, and she had consulted the leading experts in the United States and beyond. She had facts on her side.

Stymied in their attempts to attack the book’s content, Carson’s opponents turned to attacking its author. She was called a hysterical woman, a fanatic devotee of bird-huggers and organic gardeners, even a tool of subversive (read Communist) forces that were threatening America’s food supply by trying to ban all pesticides (a position Carson never took). It was the kind of firestorm of personal attacks that American climate scientists face today.

Through it all, Carson remained calm, polite, and eminently rational – all the more remarkable because she was desperately ill. In fact, she was dying of breast cancer, although very few people knew it. Her words, both written and spoken, won her plenty of supporters, including the American President, John Kennedy. By the time she died, just 18 months after the publication of Silent Spring, Carson knew she had made a difference and that the first steps were being taken to control the use of pesticides and other chemicals and limit their environmental impact.

For more about Rachel Carson and Silent Spring:

http://www.rachelcarson.org/

http://www.newyorker.com/online/blogs/books/2012/09/rachel-carsons-natural-histories.html

http://www.guardian.co.uk/global/blog/2012/sep/27/rachel-carson-silent-spring-legacy

Evolution - Not Just for Carbon-Based Organisms

by L E Carmichael

For about twenty years now, scientists have been studying evolution using a new kind of life form - a digital one.

Digital organisms are programs designed to replicate their own code, and were originally inspired by computer viruses.  Their computer-based habitats are restricted in space (RAM) and restricted in energy (the CPU time required to run the program).   As the organisms reproduce, errors are introduced into their codes at a fixed frequency - the mutation rate.  This results in a genetically variable population which is competing for resources.  And because some variants in the population can reproduce faster, while randomly-chosen organisms are periodically deleted from the system (simulating death), the composition of the population shifts over time.  In other words, the digital species evolves.

There are major advantages to using digital organisms in the study of evolution.  For one thing, complex carbon-based life forms tend to have long generation times, making it difficult to observe evolution in action.  With some exceptions, such as Darwin's finches, scientists are usually restricted to studies of the fossil record, or relationships between living species.  This research is therefore largely observational.  Experiments on evolution can normally be done only on carbon-based bacteria and viruses, and even then, it takes years to propagate the population through enough generations for evolution to occur.  In contrast, digital organisms can go through thousands of generations in just a few hours.

More importantly, because digital organisms share no history with life on earth, they are a completely independent example of evolution.  This allows scientists to distinguish general principles of evolution from quirks that might be specific to DNA-based organisms.

Some of the most interesting results to come out of this research relate to complexity.  In most cases, digital organisms develop faster replication rates by losing code - stripping themselves down to the essential instructions required for reproduction.  In other words, they get simpler over time.  Under computational scenarios, however, simple organisms can obtain numbers from their environment (equivalent to necessary chemicals or food resources).  If they have the right code (genes), they can perform calculations using these numbers (just as carbon-based life forms use enzymes to transform nutrients).  They then release the products of the computation back into the environment.  If those products are deemed beneficial, the organism is rewarded with an increase in fitness - the ability to replicate more quickly.    As mutations which allow new computations are rewarded, what results is a spontaneous increase in complexity over time.  In fact, over the course of several hundred generations, digital organisms evolve that can perform up to 50 distinct calculations.

Another mind-blowing result of this research is the spontaneous evolution of parasites - digital organisms with stripped-down genomes that piggy-back on more complex organisms, using the code of their hosts to copy themselves.  This is exactly what the average cold virus does when it infects a human nose.  What's even more incredible is that the host organisms begin to evolve parasite resistance, launching a digital arms race analogous to that between influenza and annual flu shots!

Digital organisms are a powerful model system, but there is also scientific interest in studying them as life forms in their own right.  I suspect Isaac Asimov would approve.

Science Plus Kids TV Equals Fun!

Written by Helaine Becker

For the last three years, alongside my other writing projects, I've been the staff writer for a science- and environment-themed television show for children called Planet Echo (You can see it on APTN, or watch it on line.). The segment I write is called Dr. Greenie's Mad Lab. It mixes serious, science-y information with an abundance of fart jokes. Hey, what's not to like?



Dr. Greenie mixing up something gross  - and educational! - in his lab.

The Mad Lab segment has indeed proven so popular with viewers that we are spinning it off into a stand-alone show. Some sample footage from the new show was submitted recently to the Juried competition at MIP Junior, the preeminent international trade show for children's television.
And guess what! Dr. Greenie's Mad Lab has been selected as a finalist!

The awards will be given out at a chi-chi red carpet gala in Cannes on October 7. Alas, a plane ticket to attend the event is not in my pay package; I will have to get the news of the winner via a tweet from producer Chris Greaves.

In the meantime, I'm adding tweaks to the all-new webisode for the show, an exciting project that includes both a fun plot and three interactive games kids can play on their tablet or phone.

Watch this space for news of the award winners, and wish us luck!

It’s an Animal! It’s a Plant! No, It’s a Slime Mold!

by Jan Thornhill

Dog Vomit Slime. Pretzel Slime. Wolf’s Milk Slime. Insect Egg Slime. These are just a few of the wacky names people have come up with to describe different species of myxomycetes, a group of peculiar miniature “critters” commonly known as slime molds.

A variety of slime mold fruiting bodies, including
Pretzel Slime (the snakey one) and Wolf’s Milk Slime (the pink cushions).

Photo credits: Laurence Acland, John Carl Jacobs, Jan Thornhill

Slime molds make me happy – and not just because of their wacky names. They make me happy because almost everything about them is odd. One of their oddities is that they spend part of their lives behaving like animals and another part acting like plants or fungi.

To see slime molds, it helps to get down on your knees in the woods, especially beside rotting logs in places were it’s damp and dimly lit. This is where many types of slime mold begin their lives as a loose sack of liquid, a huge single-cell with multiple nuclei. In this slimy form, called a “plasmodium,” the organism oozes slowly over and under dead leaves like a mammoth amoeba, speeding along at about a millimeter an hour. While it moves it feeds by engulfing and digesting bacteria, fungal spores, and even other slime molds. What’s really impressive is that this network of slippery muck behaves as if it has intelligence. It makes choices, veering towards food as if it’s hunting. In the lab, some slime molds are even able to figure out the shortest path to escape a maze. Stranger still, if the plasmodium is chopped into bits, the separated pieces will slowly migrate back together again!

When food runs out, or the environment becomes too dry, slime molds search out a high spot, such as a log, to do their plant-like trick of sprouting fruiting bodies and releasing spores. This is the stage where they get fancy. The giant plasmodial cell divides itself into innumerable single cells that then form the fruiting bodies. In many species, some of these cells seem to sacrifice themselves for the good of the others by creating a stalk that will hold the spore-producing structures high enough to catch a breeze. When mature, the structure bursts open and the powdery spores are carried away by wind or passing animals.

In only 7 hours, the slimy yellow plasmodium of Insect
Egg Slime(Leocarpus fragilis) transforms itself
into hard-shelled orange fruiting bodies.

More than 1,000 different slime molds have been identified, and they come in a startling variety of shapes and colors. Some look like mini wieners-on-a-stick or ice-cream cones or pretzels, though at a size only a cricket could enjoy. Others have shimmering, metallic coats, or are encased in a cracked white crust. Yet others look like delicate coral. One of my favorites, Wolf’s Milk Slime, will squirt pink goo at you if you poke it with a stick. There’s even one that can grow so large, and is so ugly, that some people blame their neighbor’s dog for its appearance in their garden or on their woodpile. That one’s scientific name is Fuligo septica, otherwise known as – you guessed it – Dog Vomit Slime.

A small, mature Dog Vomit Slime (Fuligo septica) releasing its spores.

Check out:

Artist Heather Barnett’s video-taped experiments with slime molds:

http://www.youtube.com/HeatherBarnett?gl=GB&hl=en-GB

Tons of pictures of slime mold fruiting bodies at:

http://slimemold.uark.edu/fungi/WebForms/ImageSearchForm.aspx?letter=A

http://naturalhistory.uga.edu/~gmnh/mycoherb_site/myxogal.htm

http://www.janthornhill.com

http://www.facebook.com/wonderfulwildmushrooms

Arctic Fever Update

By Claire Eamer

On August 17, I posted an article about the rapid melting of arctic sea ice this summer and the likelihood that we were heading for a record low in sea ice extent. It happened just over a week later. On August 26, the ice cover in the Arctic Ocean hit a historic low. And it's still melting.

"So what?" you might ask. Doesn't that just mean more ships, more tourists, more economic development, and other good stuff? And maybe a few uncomfortable polar bears?

Over the next few weeks, as the ice melts, the Vancouver Aquarium's Aquablog is running a series of articles about what declining sea ice means for the Arctic and for the planet. Here's the first of them: Arctic Sea Ice Reaches Record Low.

And keep an eye on the blog for updates on this record-setting summer.

Children and Dogs

This summer, my family and I spent a lot of time with small children who were relatives of one stripe or another. During several occasions, I noticed all of the toddlers had one in common: they were dog crazy. In June, an 18 month old and a four year old, along with their parents, came camping with us and our two Jack Russells. The bond was instant. The four year old spend virtually every waking moment cohorting with FrankieTexas as she calls them, squashing their names together into one. She never took her hand off the handle of the leash, she sat with them, cuddled with them, even French kissed them amidst an avalanche of giggles. After about 24 hours, the dogs lay stretched out in the grass and fine ash surrounding the fire pit, exhausted. Their little keeper held onto the leash, threatening to drag them on a walk the moment they were able to stand. I wondered if the attraction is about the dogs being about the same size? Though I was assured that the little girl is just as enthralled with an aunt and uncle’s Rhodesian ridgeback, who is nearly twice as tall as she is. Perhaps it is just my niece’s personality, I thought; an animal lover who is starting early. This idea was supported by the behaviour of the 18 month old, who was terrified rather than enamoured, despite no scary past experiences with canines. She’s slight of build, delicate in fact, with delicate features to match. She’s sweet, always smiling and usually gets fought over among the motherly segment of family gatherings. The entire camping trip, she spent all her time in her mother’s arms pointing at their adorable noses saying “doggie,” “ruffruff,” “bite me,” and most often “no.” She cried and whined and yelled “no” much louder if she was put down in their vicinity. Clearly, not all children like dogs. Several weeks later, another four year old came to visit. Shy, unspeaking and most interested in engineering feats – how to nail boards together and that sort of thing – he, too, surprised me by quietly taking the leash out of my hand. He spent the next two hours taking the dogs for walks around and around the house. Being mechanically minded, his main focus was the leash. During breaks, he tangled and untangled the leads around chair legs, and clipped and unclipped them to their collars. He discussed the best way to hold them, and the relative strength of leather versus nylon. He couldn’t remember their names, but he loved them just the same. Not long after, me and Frankie and Texas were at yet another family get together. A bigger one this time; all of the young ones were gathered in one place, a small, pleasant backyard. Unlike home, the dogs could not wander off into the fields to find the perfect patch of timothy grass to poop on. And so, it was to my utter embarrassment that my brother –in- law found a large pile of dog poo while standing barefoot on the manicured lawn. A cousin laughed at my genuine astonishment – I don’t know how it happened, I don’t know how it could be my dogs, I kept a close eye on them the entire time, they were never off their leashes. But, here it was. And two more piles close by. I felt all 30 pairs of eyes watch as I bent and picked it up. I’m not a dog person, I told myself. This was my husband’s idea. As soon as their time is up, that’s it. No more dogs. Then, the eighteen month old arrived. Approaching in her mother’s arms, she pointed at their poo-sniffing noses and said, “doggie” and “ruff-ruff.” And immediately, and delicately, reached out to grasp the leash in my hand. “You want to hold onto Texas?” I asked in astonishment. She nodded, wriggled to get down, and proceeded on wobbly feet to take them for a walk around the yard. I patted Frankie and said “good boy,” and he cocked his head in the way he does that makes his ears flop and makes me laugh. My dog poo-hardened heart melted. His tail wagged and the back half of his body wagged with it. And I wondered yet again, why it is that we have such a strong and seemingly innate connection with these meat-eating troublemakers.

The Arctic Is Running a Fever

By Claire Eamer

We've heard a lot about melting ice in the Arctic this summer, and we're likely to hear more. It takes a long time for polar ice to start melting and a long time for it to return, so the 2012 melt will continue for another month or so. That means -- almost certainly -- some new climate records. And with no sign of serious efforts to stop or slow the human contribution to climate change, there will be more records in the future.

A satellite image of the Northwest Passage, taken August 3, 2012,
shows large areas of open water.
Photo credit: NASA Earth Observatory images by Jesse Allen

Here are a few of the stories so far this summer:

Just a few days ago, scientists from the European Space Agency reported that sea ice in the Arctic is melting far faster than anyone predicted. Based on information from a satellite that measures the thickness of the ice, they estimate that 900 cubic kilometres of ice have disappeared every year since 2004. At that rate, they say, it could be as little as ten years until the day when a satellite image shows no ice at all in the Arctic Ocean at the peak of the summer melt.

Earlier this month, a giant cyclone raged over the Arctic Ocean. Storms are common at this time of year, but the researchers studying them said this was the biggest they had seen. The winds churned the ocean, breaking up the ice floes and making them more susceptible to melting.

In mid-July, a wash of warm air over Greenland triggered melting across 97 percent of the island's massive ice sheet. The last time this happened was in 1889. Scientists don't know if the melt this time is related to climate change, but they do know global warming is causing Greenland's glaciers to thin and chunks to break off, forming massive icebergs.

Does any of it matter? The quick answer is, yes. Whole ecosystems depend on arctic sea ice, from microscopic, single-celled organisms to polar bears. As the ice retreats, the open ocean absorbs more heat, warming the atmosphere above it and speeding up global warming. And melting of the fresh water locked up in Greenland's ice sheets would cause sea levels to rise around the world.

For a less quick, more detailed answer, and lots more about climate change, try some of these sites:

Arctic Sea Ice News & Analysis, from the United States' National Snow & Ice Data Center

RealClimate: Climate science from climate scientists

ClimateSight: an excellent blog by a young Canadian climate researcher