Living organisms experienced lesser gravitational pressure when life originated during Cambrian period of the Paleozoic era, especially in the sea where stronger buoyant like force under higher density of liquid medium was available due to presence of salt in sea water. The biomass of living organisms increased over geologic period. The evolution curve of the living species on earth is said to be of sigmoid shape. Size of the evolutionary living species in the earth is diminishing progressively along with slowing down of the earth’s rotation because of increase in extrinsic gravitational pull through geologic time resulting in stretched condition for the self gravity.
Present day world’s largest animal, the blue whale (more than 109 tons & 30 m in weight and length respectively), could however, continue to maintain the macro-size under buoyant force available in the sea.
Balancing act of adaptation of organisms is closely linked with gravitational pull and push of the planet earth during the particular geologic period. In the progress of evolution Homo erectus (i.e. human) came last.
It had also shown that how ‘self gravity-friendly’ load distribution and posture in the geometrical structure of the animal could make them long-lived. From all these phenotypic and indirect evidences above, it is difficult to apply null hypothesis that self-gravity is weak and cannot manifest in biological growth and development starting from origin of life in the planet. Such deductions from abductive reasoning are quite consistent with the nature of manifestation of intrinsic and extrinsic gravity in biological mass. Further investigation on the whole gamut of evolution of life is therefore suggested to substantiate conceptually and empirically on the principles of ‘self gravitation bio’