Animal Engineers
“There are creatures on Earth that have cured our diseases, built our skyscrapers, won our wars. They did this before any of us ever existed.” So said a report in a recent issue of the magazine Science Digest. Who are these master engineers/scientists? “They are the trees, the insects, the fish, the lowly forest weeds that make up the life on this planet,” said the magazine.
Here are a few accomplishments of animal “engineers” that were later invented by humans.
Modern space probes and weapons use chemical rocket-propulsion systems. But long before, the bombardier beetle was using a similar principle to protect itself. The beetle’s glands produce a mixture of two hydroquinone compounds and hydrogen peroxide. These are kept in storage chambers closed off by muscular valves. When the beetle is alarmed, the valves open and their contents flow into a thick-walled reaction area. At the same time, an enzyme is added that causes an explosive reaction, releasing oxygen. The increase in gas pressure forces the caustic solution out of the reactor and fires it at an aggressor. Ouch!
Before human sailors learned to tie knots or tailors learned to weave fibers, the weaverbird was stripping fibers from leaves and weaving them—by knotting and winding—into a hanging nest. City planners feel that a residential center has economic and communal advantages over isolated individual dwellings. Some species of the weaverbird anticipated this. They work together to build a thatched roof in the strong branches of a tree and then hang living quarters under the roof. The roof may support as many as a hundred nests.
Ahead of human engineers, the beaver was damming up waterways and altering the environment to suit its own needs. And before humans ever built canals, the beaver was doing something similar. How? Well, in order to get very large trees from the spot where he fells them to the site of the dam, he may dig an overland channel—perhaps up to a thousand feet long—and divert river water into it. He can then raft the trees down the channel to where they are needed.
In Chile a marine snail seems to have “invented” the crowbar. It has two strong protruding teeth on the lower rim of its solid shell. At mealtime it uses these to dislodge its dinner, a small mollusk clinging to a rock face. How? It wedges the teeth under the shell of its prey. Then, by pulling its foot in, it makes use of the crowbar principle to detach the prey.
Finally, did you ever realize how useful a tongue can be? Many mollusks have tongues that are built just like the rasps that we use to file wood. They use them to cut chunks of food into little pieces. The woodpecker’s tongue is like a harpoon or a fishhook. It is horny and has sharp barbs that pull hidden insects out of cracks in the wood. How hard are the tools of nature’s engineers? Consider some sea snails that feed on rock-clinging algae. On their tongues are found layers of magnetite, an iron oxide, that is almost as hard as quartz. Thus, Science Digest says: “Nature works with materials that do not lag far behind our strongest steel.”