Shelter evolution

Stars drive galactic evolution. At the end of their existence, they inseminate space with the products of their nuclear alchemy. Then, in dark clouds, sheltered from ravaging photons, molecules build up. Stars and planets are constantly being born in the cold of space. 

The Moon was created from the mantle-derived ejecta. Physically, over the aeons this may have played a useful sheltering role in protecting the planet from some meteorite impacts. Arguably more important, the presence of the Moon leads to the tides. These create the intertidal and near-subtidal habitat with rapidly varying geochemical settings, from wet submarine to dry subaerial, in which sediment is repeatedly flushed with fluid. Such cyclically varying habitats may have been vital in the early evolution of microbial biofilms and eventually microbial mats. 

Polar bears, however, cannot leave their coal mine —evolution has left them supremely adapted to life on the ice pack, where they are efficient hunters, preying largely on seals and other marine life. But off the ice, they cannot hunt, mate, or shelter their young. They starve and die. 

The observation that in the case of air flow over viscous liquids (p > 15cp) the K-H instability occurs at a lower gas velocity than the Jeffreys instability (Hanratty [53], Andritsos et al. [113]) seems to evolve from the neglect of the increase of the sheltering coefficient with increased liquid viscosity as shown in Figure 21. Figure 16 implies that the K-H mechanism and the Jeffreys-Miles-Benjamin sheltering mechanism both share important roles in the evolution of waves over viscous liquid layers. 

The potential host community can be perceived by parasitoids through any of the above stimuli from the host, the food or shelter of the host, organisms associated with the host, or interactions between these factors. Plants appear to play an important role in potential host community location, partly because plants are the source of food for most hosts. It has been contended that the evolution of the parasitoid habitat in Hymenoptera may have stemmed from a previous plant-parasite relationship (Malyshev, 1968). If true, such a relationship would provide insight into the role of plants in the host selection process. The importance of plants in host community location is further supported by the observation that there is less tendency for parasitoids to select phylogen-etically related hosts than unrelated hosts found on the same plant (Cross and Chesnut, 1971). 

In the systems characterized by the strong hydrogen evolution which cause the change of hydrodynamic conditions in the nearelectrode layer, the formation of dendrites mainly occurs in sheltered parts of the surface area, such as the bottom of holes (Fig. 1.21) [64]. 

The primitive savage endeavors of mankind to secure protection against the elements and from attack included seeking shelter in rock caves, learning how to build tents of bark, skins, turfs, or brushwood and huts of wattle and daub. Some of such types crystallized into houses of stone, clay, or timber. The evolution of mankind is thus linked to the history of building materials. 

Man has been surrounded by ceramics from the very beginning. The natural tendency of humans is to put to use any and all available materials to satisfy their needs. Thus, the earliest humans used the natural ceramics around them—the boulders provided them shelter, and stones were used for defense and hunting. As time passed, man learned to chip rocks to make tools, leading to the evolution of hand-held axes. About 70,000 years ago. 

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