Human evolution can be traced back 4 million years ago to Australopithecus, the southern ape, in Africa. At that time our ape-like ancestor had been spending much time in trees of the forest and walking on the ground with all four limbs, similar to chimpanzees today. With the terrain turning into the savannah as it is today with few trees, some the apes adapted by coming down from the trees and surviving on the ground. Once on the ground, it is thought that some apes might have started walking on two feet in order to increase their visual perception of their surroundings, to see over the tall grasses of the African savannah, and avoid predators. Once walking on two feet, this freed the arms, and the apes slowly learned that they could use their arms for many previously unforeseen uses. Such uses might include setting up some sort of camp, gathering fruits, vegetables and nuts in the savannah and returning that to the camp.
About 3 million years ago some Austalopithecus learned that they could use tools to make gathering easier, stones to dig and cut with, and perhaps animal hides to build shelter and carry their food in back to camp, and with that Homo habilis, the handy man, was born. These tools may have led to the use of similar stone tools for hunting prey, as in clubs and spears. These tools were perhaps the first permanent use of technology by human ancestors 3 million years ago, manipulating the environment for their own survival, and it has not stopped since, making humankind the dominant species on the earth. Technology refers to anything humans create that makes their survival easier and their lives better.
Homo habilis lived from 3 to 2 million years ago, and evolved into Homo erectus, or upright man 2 million years ago. Homo erectus survived until about 300,000 years ago. Home erectus left Africa through the middle east and settled all of Eurasia over this time period, evolving into additional human species such as Homo neanderthalis and Homo floresiensis. Homo erectus learned how to create and use fire, started cooking and wearing clothes. They were also hunter gathers.
Approximately 300,000 years ago, Homo erectus was still present in East Africa, and evolved into Homo Sapiens, or wise man. About 70,000 years ago these Homo sapiens started a second wave of migration, spread out of Africa and settled the rest of the world - by 45,000 BC they had reached Australia, and 20,000 BC reached the Americas. Neanderthals went extinct 30,000 years ago, and Homo floresiensis went extinct about 17,000 years ago, leaving Homo sapiens as the only surviving human species.
We are presently Homo sapiens sapiens, and 12,000 years ago we created the agricultural revolution. The Agricultural Revolution was the wide-scale transition of many human cultures from a lifestyle of hunting and gathering to one of agriculture and settlement, making possible increasingly larger and denser populations. Agriculture led to the first civilization, that of Mesopotamia in the fertile crescent in 6500 BC, and the beginning of law as we know it today as first written in Hammurabi's code. Other early civilizations include the Indus valley civilization in what is now India, ancient Egypt, the Mayan civilization in what is now central America and ancient China. The scientific revolution started in the 1500s with developments in mathematics, physics, astronomy, biology and chemistry that transformed the views of society about nature. Science is the study of the real world based on fact and truth. The scientific revolution led to the industrial revolution. The Industrial Revolution was the transition to new manufacturing processes starting in the period from about 1760 to sometime between 1820 and 1840, and progressed into the 1950s. This transition included going from hand production methods to machines, new chemical manufacturing and iron production processes, improved efficiency of water power, then increasing use of steam power, the development of machine tools, the rise of the assembly line, factories, automobiles and the oil industry.
We are now early in the digital revolution. The Digital Revolution is the change from mechanical and analogue electronic technology to digital electronics which began anywhere from the late 1950s to the late 1970s, with the adoption and proliferation of digital computers and digital computing that has now impacted every field and most aspects of our lives. The term also refers to the sweeping societal changes brought about by digital computing and communication technology during the latter half of the 20th century, the rise of the internet in the early 21st century, and continues today. The Digital Revolution marks the beginning of the Information Age.