GAIA

About 4,65 thousand million years old, this planet is predicted to support 6,5 thousand million members of the human species by the year 2000 and 8,5 thousand million by 2025.

Its primary energy sources are Solar radiation and geothermal radiation caused by both internal radioactivity and the energy contributed by the original gravitational accretion, re-melting and contractive solidification that occurred during its creative phase. The delicate equilibrium between these energy sources that results in an average global temperature of 14 degrees Celcius enables the thriving of the planet's more than 1,5 million different species of fauna and flora. The planet is unique in its solar system as its surface holds 1 376 million cubic km (330 million cubic miles) of liquid water.

The planet is unusual in that it has a biotically processed atmosphere. The primeval atmosphere, consisting mostly of hydrogen and helium, was replaced by outgassing from the interior as fractionation of the Earth's component materials settled into the differentiated zones of crust, lithosphere, aesthenosphere and core materials according to their specific gravity during the re-melting phase. Although the earliest living entities were anaerobic bacteria, the development of photosynthesis converted a large fraction of the early atmosphere to oxygen, enabling the development of more advanced lifeforms. The vast number of living entities in the biomass weave a web of interdependence by feedback control vectors that sensitively control the viability, survival and thriving of all other members.

Characteristic of Homo Sapiens, ("Wise Man") as well as other species, is the spectrum of atavistic evolutionary atributes demonstrated during embryonic recapitulation - a phase during which four gill clefts are visible on each side of the neck and the presence of a tail which is re-incorporated by the end of the eighth week of gestation. Nevertheless, some ativistic organs such as the vermiform appendix which alludes back to an earlier herbiverous precursor, remain present. A further such interesting structure is the recurrent laryngeal nerve (RLN) which evolved from the vagus nerve in a piscine progenitor where it sends direct branches to each of the gill arch ducts. The modern RLN descendent of the fish's fourth vagus now passes down from the brain, down to the heart in the thorax and back up again to the larynx - a seeming inefficiency in unnecessary length and detour.

All terrestrial and marine tetrapods have a pentadactyl (five-digit) limb structure. The forelimbs of a bird, bat, human and whale are all constructed from "homologous" bones, even though these have become structurally modified by functional adaptation and specialisation. Some mammals such as horses and some lizards have less than five digits in the adult stage although even these develop from a pentadactyl precursor and lose one or two digits during development.

The development of perspective in Man's outlook on his home planet and its position in the cosmos has undergone progressive "decentripisation" since early Mesopotamian views on cosmology. In the second century a.d. the Ptolemaic Geocentric system regarded the Earth as the centre of the universe. The Copernican Heliocentric system robs Earth of this anthropocentric location. The development of optical, radio, X-ray and gamma-ray astronomy shows the Earth, significant as it is to our species, to be an insignificant speck orbiting yet another in an endlessly ramifying universal system of increasing cosmic sophistication and beauty. One of the last cosmo-psychological hurdles to overcome, is the centrist idea that although the Earth now occupies a properly adjusted democratic position in the cosmic scheme of things, it is still the biological centre of the universe. This last compensation for anthropomaniacal insecurity is fast being eroded by empirical scientific insight into a panbiotic origin of life - a view of a universe where life is as common as the stars themselves.

A large contingent of Homo Sap. believes itself to have been separately created as a species by an act of divine creation, where the possibility of a divinely modulated evolutionary mechanism is not often considered.