Spiderman vs. Darwin -The Science Behind the Fiction
Spiderman fans would love a passage in Charles Darwin's Voyage of the Beagle where he describes a life and death battle between a Pepsis wasp and a large black spider of the genus Lycosa. It was a battle equal to any of the urban feats of our 21st-century Peter Parker Spidey-man. I won't spoil the ending, so you'll have to read the book (or at least p.18) to see who won the battle.
Let's take a look at how Spiderman's feats stack up against the real science of contempoarary biologists.
If Darwin were alive today he would agree with contemporary biologists and attest that for our urban Spiderman hero the web's the thing, as any Spider-Man fan will see when Spider-Man 3 opens: Spider silk is stronger than steel, more elastic than nylon, and can stop a 747 in mid-flight.
And while "Spidey-sense" might be a comic-book creation, some of Spider-Man's other abilities are ripped straight from nature:
Spider-Man's high-speed glides through the Manhattan grid of highrises might not be too far off the truth. Some spiders cast silk into the wind and fly hundreds of miles, using their silk threads for ballooning by extruding several threads into the air and let themselves become carried away with upward winds. Although most rides will end a few meters later, it seems to be a common way for spiders to invade islands. Many sailors have reported that spiders have been caught in their ship's sails, even when far from land.
Spider silk is a remarkably strong fiber. Its tensile strength is comparable to that of high-grade steel, with a ratio of tensile strength to density is perhaps 5 times better than steel — as strong as Aramid filaments, such as Twaron or Kevlar. A strand of spider silk long enough to circle the earth would weigh less than 16 ounces.
Like our urban lyconsian human, a female specimen of Argiope appensa wraps her prey in silk.Spiders normally use their silk to make structures, either for protection for their offspring, or for predation on other creatures. They can also suspend themselves using their silk for the same reasons.
The Trapdoor spider will burrow into the ground and weave a trapdoor-like structure with spindles around so it can tell when prey arrives and take it by surprise. Costa Rican zebra tarantulas spun silk from their legs as well as their abdomen. Tarantulas spin silk from their feet.
Spider silk is made of complex protein molecules. This, coupled with the spider's preference—as a predatory animal—for isolation from other species, has made the study of the substance quite challenging. It is the interplay between the hard crystalline segments, and the elastic amorphous regions, that gives spider silk its extraordinary properties.
Posted by Casey Kazan.
Comments