ABSTRACT
This chapter introduces the Genome Project and discusses its medical significance. The principles of genetics and historical selective cross-breeding are explained and the early experiments of Mendel, now recognized as the founder of modern genetics. The discovery of DNA, its structure and significance are discussed.
The two epigenetic forces in evolution, ‘natural selection’ and ‘conditions of existence’ which Darwin considered so important, are considered, the latter being more powerful in dictating changes in evolution. The two major ‘conditions of existence’, one climatic (the late Miocene drought) and the other tectonic (formation of The Great Rift Valley), which were vital factors in precipitating and influencing the evolutionary split between the first hominid and our two closest cousins, the gorilla and the chimpanzee in East Africa are explained.
The late Miocene drought decimated the forest habitat, and the continental shift of the East African plate with inundation and formation of the Great Rift Valley and the Olduvai Gorge were the two epigenetic forces which created a changing environment and habitat in which one branch of the family, ancestral to hominins, learned to survive by finding new sources of easily available aquatic food in the marshland, rivers, salt-water lakes and the sea shore. (200 words)
