This book is a compilation of two related scientific researches in physics applied to observable geographic phenomena on Earth. In essence, the book is publishing two completely new theories on planetary gravity and how it impacts the lives of living things on it. The first part of the book publishes the research and a new theory on how gravity influences the life sizes, rate of life activities, and life spans of all living things. The second part publishes the research and new theory of the Great Crunch. The great crunch is a postulation that about 50 million years ago, the Earth became smaller under certain forces, and this caused gravity to increase. This change brought about the extinction of species and the subsequent gravity-induced evolution of living things. Finally, the book has an addendum or annexure in which a warning of a possible future Earth crunch will bring about severe consequences to humankind and other living things. Advice is also given to business entrepreneurs who wish to colonise other planets in the future to guard against the dangerous effect of planetary gravity different from our planet Earth.