Engineering Animals: How Life Works
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The alarm calls of birds make them difficult for predators to locate, while the howl of wolves and the croak of bullfrogs are designed to carry across long distances. From an engineer's perspective, how do such specialized adaptations among living things really work? And how does physics constrain evolution, channeling it in particular directions?
Writing with wit and a richly informed sense of wonder, Denny and McFadzean offer an expert look at animals as works of engineering, each exquisitely adapted to a specific manner of survival, whether that means spinning webs or flying across continents or hunting in the dark-or writing books. This particular book, containing more than a hundred illustrations, conveys clearly, for engineers and nonengineers alike, the physical principles underlying animal structure and behavior.
Pigeons, for instance-when understood as marvels of engineering-are flying remote sensors: they have wideband acoustical receivers, hi-res optics, magnetic sensing, and celestial navigation. Albatrosses expend little energy while traveling across vast southern oceans, by exploiting a technique known to glider pilots as dynamic soaring. Among insects, one species of fly can locate the source of a sound precisely, even though the fly itself is much smaller than the wavelength of the sound it hears. And that big-brained, upright Great Ape? Evolution has equipped us to figure out an important fact about the natural world: that there is more to life than engineering, but no life at all without it.
Movement to obtain both the time t0 required to take one step5 and the average walking speed v = L/t0. (L is the distance moved by the body mass during t0 , as shown in Figure 17a.) A dimensionless parameter called the “Froude number” emerges from this analysis: Fr = v 2/gl, where g is the acceleration due to gravity and l is leg length. It transpires that the Froude number pops up in many areas of physics and engineering—it first appeared in the context of fluid flowing past ship hulls— and it.
Complicated—aerodynamic effects close to the ocean surface (so close that their wingtips may touch the water). Air displaced by a moving bird bounces off the surface and provides it with extra lift—the ground effect. Additionally, ocean waves cause air near the surface to move in a manner that can be exploited by an experienced glider pilot or by an albatross. This effect is known as wave lift.19 Swimmers Just as aerodynamics is recruited to help understand flying birds, so hydrodynamics is.
Categories. Thus, when an egg hatches, the larva gets moved to the nursery with the other larvae. This behavior is just a variation on foraging: here, the ant encounters a larva surrounded by eggs and so picks up the larva and wanders through the nest until it finds a place where there are other larvae. It then drops its charge and wanders off. In the same way, if it finds a dead ant, it will carry it until it finds more dead ants. As a result, ant colonies routinely dispose of their own dead by.
Of time. If nothing happens go back to moving. 4. If you encounter a stationary ant, climb on top of it and keep moving forward. 5. If there’s another ant hanging off you, don’t move, but emit a pheromone call for help. The results are shown in Figure 43, where we can see that ants can indeed build bridges. The tree-dwelling weaver ants of the African, Australian, and southeastern Asian forests go one better: they use much the same algorithms to bridge high-altitude gaps between branches and.
Throwback to their origins in those earliest single-celled creatures. All other senses use intermediary cells or chemical signals to provide a link between the external detectors and the actual remote sensing 158 [To view this image, refer to the print version of this title.] figur e 49 (a) Snail, (b) lobster, (c) shark, and (d) otter: how do they really taste? We thank Anita McFadzean for these images. receptor neurons that process the information. This includes the sense of.