Paul Chafe - Destiny's Forge-A Man-Kzin War Novel

The kzinti culture is both more homogenous and richer than human culture. In a very real sense there are not one but many human cultures, since civilization arose not once but several times on Earth, each time in complete isolation and independence, separated by insurmountable geographic barriers. By contrast, both linguistic, historical and (where available) genetic evidence indicate that civilization arose on Kzinhome only once. In geocultural terms, this can be explained by Kzinhome's relatively small (~50%) percentage of water cover and proportionally larger contiguous continental area, combined with the smaller range of climatic conditions over the non-polar regions of the planet. This is caused by the denser atmosphere and the tropical wind belt phenomenon, which acts to pump heat from the equator to the mid-latitudes. This arrangement can be expected to have facilitated the movement of trade and technology over isoclimatic lines with relative rapidity. At some point relatively early in the civilization cycle the primary kzinti culture was established and thriving planetwide. On genetic evidence it is certain that the kzinti species passed through a population bottleneck approximately ten thousand generations ago for unknown reasons.

Given the evidence of a single start point for kzinti civilization, we can argue that an evolutionary stress caused the bottleneck and triggered runaway sexual selection of intelligence with resultant rapid and concurrent development of bi-quadrupedal posture, language, and tool use as species traits. It seems likely this stress was a massive climatic shift brought about by the slight eccentricity in Kzinhome's orbit caused by gravitational interactions with the gas giant Hgrall. This posited orbital shift, occurring approximately 200,000 years ago, would have increased average solar flux, in turn increasing the average surface temperature as much as 3 degrees Celsius, extending growing seasons and accelerating the rate of water circulation through the atmosphere and hydrosphere. The combination of these effects formed extensive rainforests throughout the tropical and temperate zones. Simultaneously large sections of the continental interiors were reduced to desert. The higher rate of photosynthesis has led directly to the high (~30%) oxygen levels seen in Kzinhome's atmosphere today. A general rule of planetary evolution states that the average mass of animal species increases with increased solar energy flux. This is due to both the greater availability of food through increased plant growth, which supports a heavier food chain, and the greater availability of oxygen due to increased photosynthesis, which allows the high metabolic rates necessary for large, active animals to exist.

Although humans are accustomed to seeing the two-meter kzinti as large predators, in their native ecosystems they are small in relation to most high order fauna in their ecological range, small with respect to their primary prey species and small with respect to other predators with which they compete. Typically, large land predators take prey no more than twice their weight, and usually less than their weight. By contrast, lone kzinti will stalk and kill zerkitz up to ten times their weight, and hunting parties will take a'kdzrow of up to twenty-five metric tons. In most cases where evolutionary forces lead to an increase in prey species size we expect to see the predator species increase along with them. However, in the case of the kzinti the large predator niches remained occupied by competitors such as the v'speel stalker and the pack hunting grlor.

This suggests that the kzinti were forced into the intelligence niche because their customary prey animals increased in size with the climate change but they themselves could not because the large predator niches were already occupied. As their prey grew larger the large predators flourished at the expense of the smaller early pre-kzin, driving them to the edge of extinction. This would have pushed the pre-kzin toward the cooperative hunter niche, which requires the development of complex signaling and a basic social structure. These developments set the stage for the evolution of intelligence. This picture is plausible but incomplete, and it is important to understand that while the individual links in this chain of reasoning have all been verified, to the extent possible through kzinti documentation, the actual proof of the cause and effect relationships asserted will have to await detailed research on Kzinhome itself.

Regardless of the root causes of the genetic bottleneck event, the effects on kzinti development are clear. The kzinti speak a single language, although there are many dialects, and extremely separated dialects have difficulty communicating. Given the limits imposed by speed-of-light communications in an interstellar empire, identical linguistic groups have had ample time to diverge but have not. It could be argued that this lack of linguistic flexibility is evidence of a more instinctive, less flexible language facility, hinting that kzinti are less intelligent than humans. However the Hero's Tongue is a fully combinatorial language in the sense of Gdel, i.e., a formal system capable of making statements of arbitrary complexity. There is therefore no thought that cannot be expressed in the Hero's Tongue. Further, kzinti are gifted mathematicians, which again requires thought processes capable of handling problems of arbitrary complexity. In addition, both the language areas and visual cortex in the kzin brain are highly developed and both larger and more finely structured than in humans.

This last fact may provide an answer to the puzzle of the Hero's Tongue's strange cohesion. It is known that the kzin population is richer in telepathic adepts than the human population, and it is known that the brain processes used in telepathy make extensive use of both language and visual circuits in humans. In the visual system this is known to correspond to the high demands of the active predator ecological niche. The low genetic diversity of the kzin race may have facilitated the emergence of a telempathic sense due to the high degree of correlation of thought and emotional processes between individuals. There is then a natural evolutionary pathway toward making use of the processing power of both visual and language brain circuits in order to extract increasingly detailed information from the telempathic sense. This development can in turn have locked in those brain circuits to the demands of telempathic processing. In the visual cortex these effects may not be noticeable, since the visual cortex is also locked into processing patterns that correspond to a verifiable external reality; however, there is no single correct combinatorial language system, which leaves the language centers of the brain free to select any of an infinite number of equally valid symbol systems.