In order for a species to survive anywhere in the world, that species must evolve and adapt to its surroundings to better itself for survival. Evolve means to develop by gradual changes. When an organism evolves, it will eventually change it's external appearance and the human race is a good example of that. Since the beginning of time, humans have evolved and adapted from ground-dwelling pre-humans to the emergence of Homo sapiens sapiens along with the technology and culture with it.
According to the theory of evolution, a critical development occurred when the ape family became differentiated into the tree-dwelling apes and the ground-dwelling types known as hominids ("prehumans"). The remains of Australopithecines, the earliest known hominids, were discovered in South Africa in 1924. Australopithecines had an erect posture but an apelike brain. Various sites in East Africa have produced a remarkable collection of Australopithecines fossils that can be dated back 3.9 million years. Because they are the oldest hominid fossils, Africa is called "the cradle of mankind." In 1974 an expedition led by Donald Johanson found a female skeleton. This skeleton was named Lucy. Lucy is nearly 50 percent complete and between 3 and 3.5 million years old. Lucy was apelike in appearance, 3 feet 6 inches tall, and walked fully upright. In 1976 the British anthropologist Mary Leakey discovered at Laetoli, in northern Tanzania, the fossil jaws and teeth of eight adults and three children, between 3.35 and 3.75 million years old. Later, she uncovered 57 footprints, set in solidified volcanic ash, made by two individuals - the oldest known marks of human-like creatures on Earth.
The first species of the genus Homo was the Homo habilis. The Homo habilis succeeded the Australopithecines and was discovered in 1964 by Mary Leakey's husband, L.S.B. Leakey, at Olduvai Gorge in Tanzania at a site some 1.