Darwin Not Given Enough Credit for Animal Engineering
Daniel E. Lieberman (Harvard) was impressed with Steven Vogel’s new book, Comparative Biomechanics: Life’s Physical World (Princeton, 2003), which he reviewed in Nature.1 He considers it a much-needed general textbook on biomechanics, the study of ways living things solve physical problems. For instance, animals and plants need to generate forces to either move or stay put. Lieberman praises Vogel’s book as fun to read and filled with tremendous examples:
- Prairie dogs build their tunnels to ventilate based on the Bernoulli principle.
- Basilisk lizards are able to run on water. A human would have to weigh just 4.6 grams to accomplish that feat with our feet.
- Fleas accelerate at 2000 meters per second, 20 times greater than a Space Shuttle launch.
- Silk has a tensile strength similar to that of steel.
- Oak trees generate 500,000 pascals of pressure by evaporation.
“Nature is a pretty impressive engineer,” Lieberman confesses.
The physical world poses many basic challenges, such as gravity, viscosity and pressure gradients, to all living creatures, which in turn have evolved an astonishing array of solutions. Many of these, such as paddles, valves and hydrostats, are so widespread that we rarely notice them. Others perform so well that we marvel at their superiority to human-made devices.
The physical problems solved by living things extend from “how proteins fold to how whales float.” These things are best studied by engineers, who can employ their talents “deducing and testing the inherent principles and mechanisms by which things fail, work or can be made to work.” The only criticism Lieberman had was that Vogel didn’t shed enough light on evolution:
In Vogel’s world, plants and animals receive equal treatment in the context of the physical problems they encounter. In that sense, the comparative method he uses is based on problems of physics, not evolutionary relationships: tubes are treated as tubes, regardless of what kind of organism they serve. Regrettably, this perspective leaves little room to explore key problems in evolution. Vogel mentions only in passing various debates on topics such as constraints, adaptation and the mechanisms by which organisms can or cannot alter in response to changes in their environment. Of particular note, he sidesteps the issue of optimization and the extent to which natural selection drives organisms towards supposedly better ways to overcome the challenges posed by their particular environments.
Despite that little shortcoming, he thought the book was destined to become a well-worn classic.
1Daniel E. Lieberman, “Engineering for Animals,” Nature 428, 893 (29 April 2004); doi:10.1038/428893a.
Ha! This is funny. Please, Mr. Vogel, can’t you give Charlie just a little credit? I’m afraid the creationists and ID people are going to latch onto this book. Can’t you tell us just a little bitty just-so story about how these masterful engineering feats evolved, so that we can use it in the public schools?
Vogel, in essence, replied, Natural selection? I have no need of that hypothesis.
Congratulations to Dan Lieberman for a well-deserved Stupid Evolution Quote of the Week.