July 31, 2010
All spiders make silk. For many spiders, silk is about building someplace to stay still. But for jumping spiders, it's about having the freedom to move around. Fast.
Jumping spiders make up the family Salticidae. This is the biggest spider family, numbering about 5,000 species. No matter where you live, you've probably come across a jumping spider one time or another in your home. They're usually compact, and because they're diurnal, you may find them traveling across the kitchen table or a windowsill or wall in broad daylight. (Also, it has to be said: magnified, they're quite quaint. There's something about those big, forward-facing eyes and fuzzy chelicerae that evoke King George V on a bad hair day.) Don't torment it, but it's really fun to nudge a jumping spider from behind and watch it spring away. Even more fun is to watch one jump perpendicularly away from a wall and then seemingly defy gravity as it lands back on the wall a few inches down.
You have to look closely to see the secret behind this daredeviltry. Salticids belong to the spider infraorder Araneomorphae, all of whose members produce major ampullate, or dragline silk. All araneomorphs can dangle on major ampullate silk threads. In fact, it's likely major ampullate silk evolved because stronger silk allowed more spiders to drop out of the way of danger. Salticids just took this innovation and leapt with it. This super-strong silk lets them recover from any jumps they might miss: it reels out from their spinnerets as a safety line as they travel through the air.
We're only beginning to understand how much we don't see and don't hear and otherwise don't sense what's going on in the miniature world of the jumping spiders. I was reminded again of how much sheer imagination and creativity are involved in experimentation--qualities often masked by the dry prose of scientific papers--when I recently came across this amazing PBS film about Damian Elias's research on jumping spider courtship. Enjoy:
July 27, 2010
We're really excited that a couple of top-notch reviewers in England have recommended Spider Silk to their readers. For more info, go to the Press/Links tab. But here are the short versions:
Simon Barnes, The Times, 3rd July 2010: "This is a fascinating and readable account of one of the great, overlooked mysteries of life."
Tibor Fischer, Sunday Telegraph, 11th July 2010: "The book is full of amusing facts and observations…Definitely for the general reader with a keen interest in natural history."
July 23, 2010
We recently wrote about golden spider silk woven into a traditional Malagasy tapestry. Spider Silk co-author Cay Craig is just back from Madagascar, where she spearheads the Conservation through Poverty Alleviation project, known as CPALI for short. And she's brought lengths of a brand new kind of Malagasy textile made from bronze-colored native silk moth silk.
It's impossible not to pun that silk has threaded together various places, projects, and insights over the past 30 years of Cay's life. Cay first knew she wanted to make field research her life's work when she spent time as an undergraduate in Stanford's Human Biology program working with Jane Goodall at Gombe in Tanzania. Working later in Costa Rica, she realized that spiders and their silks would allow her not only to combine field research with her more recent interest in evolution but also to conduct experiments that would be impossible with larger or more mobile animals. And so her career as an arachnologist and eventual authority on silks and silk proteins began.
Visiting Gombe in 2002, Cay was devastated by the intervening damage to the forests surrounding the national park. She believed local people often had no option but to rip into the forests surrounding their villages in order to gain cropland or firewood. If there was some way to provide them an economic incentive to plant rather than cut down trees, she figured, they might gain a little more control over their economic situation and revitalize the buffer forest around the park at the same time.
That's what CPALI is doing at the edges of the Makira Protected Area in Madagascar – home of the silky sifaka and also site of some of the worst illegal rosewood harvesting. The latest tangible result is a length of bronze-colored, diaphanous textile created by sewing together hundreds of ironed-flat silk moth cocoons.
With the light shining through it, this textile is otherworldly and yet earthy, seeming simultaneously mineral and animal. A number of designers are interested in its possible use in wall coverings, lampshades, and window treatments. As sales increase, more farmers can join CPALI and additional forest loss to slash and burn agriculture avoided.
July 16, 2010
We awoke as legends this morning.
My younger daughter calls me to the front door, which she had opened in order to retrieve the newspaper. Smack dab framed by the doorway, silk stretching from porch post to ceiling lamp to the pot of fuchsia hanging on the wall, is an orb web. Fantastically regular in layout, almost completely translucent in the shade of the porch. Its maker rests dead center on the hub. I'm not photographer enough to capture it for posterity. I'm not systematist enough to guarantee it's an Araneus diadematus, or garden spider, but I'm pretty sure. (And I discover later in the morning, as I run along threads through that other Web, that just such a spider starred in the Italian documentary short Epeira Diadema--Epeira being the genus name before Araneus supplanted it--made by Alberto Ancilotto and nominated for an Oscar in 1952.)
Webs strung across entrances have supposedly saved numerous influential personages over the centuries. David trying to get beyond the reach of King Saul, Mohammed fleeing Mecca, and Joseph and Mary trying to save Jesus from King Herod's soldiers--legend has it that in each of these cases and others a cave served as refuge. A spider then hung an orb web across the entrance. Passing enemies: "Don't bother looking in there. That spider wouldn't have had time to make that web." If said enemies had been more interested in arachnology, they would have known orb weaving usually takes only about an hour.
This morning, my daughter and I looked less than legendary as we limboed under the web to get to the street. But this start to the day was so nice that our tiny new resident may as well have posted TERRIFIC in 48-point aciniform type.
July 6, 2010
We stopped in at the American Museum of Natural History in New York over the weekend to see the one-of-a-kind tapestry woven in Madagascar from the silk of Nephila madagascariensis, one of the golden orb weavers. Weaving was a highly developed art in Madagascar through the middle of the 20th century, and Europeans marveled at Malagasy creations in raffia, silk, and cotton, but especially silk. Malagasy royalty gave silk textiles to foreign leaders as they tried to establish or cement strategic alliances.
But that was silkworm silk. Weaving textiles from spider silk has never been practical, even in Madagascar, where giant golden orb weavers abound. When the tapestry was unveiled last autumn, The New York Times explained how Simon Peers, who has partnered with Malagasy weavers over the last two decades to revive their traditional art, put into play a plan to create the world's largest--and certainly most beautiful--piece of spider silk cloth. And the AMNH made a film, which you can see here. But if you can, get to the AMNH yourself to see this almost incredible piece of work. I dare you to keep your fingers off the case--they'll want to reach in and feel those wandering fringes where the silk looks still untamed.
July 1, 2010
Porter Square Books, a great independent bookstore in Cambridge, MA, offered us the venue for the first official Spider Silk reading, and about 90 people turned out! The audience asked great questions and seemed just as amazed at and intrigued by the diversity of spider silk uses as Leslie was when she first started working with Cay. Thanks to Ellen, Nathan, and Josh at PSB and to all who attended.