At the beginning of the human species, that is where it diverted (in the ways that it diverted) from other species to develop what we see today as the understanding of existence, conscious thought, and so on, humans were not much different than the rest of the world's animal species. But as time passed a mental (and also the more clearly documented physical) evolution took place starting somewhere between 4 and 6.5 million years ago give or take a few hundred millenniums. At this point, human thought, like other mammalian thought still seen today, was primarily focused on survival, instruction of the young by example, and basic systems of communication which were mostly non-auditory -- relying mostly on gesture and emotional bursts.
As the human species continues to evolve, it, as a select few species do (all mammalian or birds and mostly primate), begins to use simple tools to dig in the earth or a bit later use as weapons. This is similar to the way chimpanzees today can use sticks to pull up roots and dig out termites or fashion spears by sharping sticks with their teeth. Humans did the same as these animals, granted considerably earlier on than it is believed these other species alive today began.
As generations pass the necessity for communication becomes more and more important. That is, members of the proto-human species who are more able to express themselves are more likely to survive to reproduce. Speech evolves in this fashion as does with it a more complex ability to think and a larger brain size. At this same point, the proto-human species becomes bipedal (primarily) and turns away from the more primate-esque forms of arm-based tree climbing. There is more food on the ground than in the trees -- protein specifically which grows muscles creating stronger, larger, and smarter humans. Those who can walk upright have a distinct advantage over those who cannot (today's chimpanzees for example). The human species becomes omnivorous. Protein sources are readily available and the proto-human who can speak can convey messages and hunt in packs to bring down even larger animals. Human evolution continues thusly in this vein for a very long time.
Expressions of art (cave drawings) appear more likely than not as a means of expression instead of for aesthetic purposes. This marks a huge change in the proto-human species and again a breakaway. To this point the human species is not solely one branched. Contrarily there are several groups who have simultaneously evolved from tree-living primates. Neanderthals, of course, are the most popularly known today. And, in the case of Neanderthals, it is believed that they died out because of an inability to compete with the Cro-Magnon human species (our progenitors circa 60,000-20,000 years ago). Both subgroups of primates had learned to use stone tools. Both could light fires. Both could build comparable shelters. But, Neanderthals did not acquire quickly enough (perhaps they would have in time if they hadn't gone extinct) the ability to create complex tools which serve distinctive purpose -- to multiply the ability to complete a task.
The Cro-Magnon discovered this ability to multiply their ability to complete tasks. That is, they created fishing nets to catch more fish with less effort. They planted food so that they did not need to search for it. They traded goods with each other even over long distance. And they built rafts and later boats to navigate the seas. None of these advantages could the Neanderthal claim to have. Likewise the Cro-Magnon were omnivorous and when meat was short they were more likely to survive than the carnivore Neanderthals. And additionally, humans learned to store food in preparation for shortage, which again Neanderthals did not. Therefore as two subspecies compete on the same land for the same resources, it is clear why the Cro-Magnon win. The evolution of those who were able to master task multiplicity, food storage, and agrarianism where obviously those who were going to survive and procreate. They are those who we are descendant from.
Towards the end of the Cro-Magnon period, animal domestication began to offer humans a reliable and steady source of meat the same as farming advancements had stabilized the ability to grow crops and increase crop yield (weather permitting). Music and art had appeared by no less than 20,000 years ago. They were means of conveying information orally, as was the creation of complex oral language. Those who can pass on information quickest are the most likely to pass on their genes as well as they are the most prepared and knowledgeable hunters, farmers, etc.
The next turn the human species would take would remove it from the animal world even farther. Roughly 10,000 years ago the first cities began to form in the general area of Syria and Iraq and later Egypt. Humans became so successful in farming that they no longer could be classified as a nomadic people as a whole. (Granted nomadic tribes remained in areas where resources were scarce, as they continue to this day.) They were able to garner enough food through task multiplicity that if grouped together in large groups they could support the entire proto-city population without every individual having to farm, hunt, or raise livestock.
This ability to have extra people not working on finding or else growing or raising food, leads to another advancement of the human species. Those who have nothing to do will inherently find something to do to earn them the right to eat. Trade and barter had existed since the Cro-Magnon times, but now instead of food specifically, these people needed to find new things to trade with so that they could eat. And they did. Those who don't need to worry about acquiring food have the time to begin to think about other things. Specifically, they are able to think of the world around them. Using these thoughts new tools were created and new ways to manipulate the world to our benefit arose. By 7,000 years ago irrigation appears. Those who farm, but for whom it doesn't take their entire effort can delve into such thought necessary to create this. Pottery to store extra food and drink also appears at this same time. 5,300 years ago the ability to create bronze (fuzing copper and tin) arises. Smiths are able to forge bronze tools and weapons which are much more durable than their stone counterparts. Those who have these tools are those who will live to procreate. These people are the progenitors of early Europeans and East Asians primarily, a notable exception is the Egyptians. The power of bronze dots this period in history with competing factions fighting for the same resources and lands.
This trend continues as humans continue to use this new bronze technology to further free up time and amass goods so as to be able to further strengthen their ability of task multiplicity. Large cities begin to grow along waterways where trade, herding, and agriculture can be most profitable. These areas are most in demand and most wars are fought either defending them or conquering them. Law is codified to organize increasingly large groups of people so as to lessen confusion and inhibit activity which decreases the ability for the human species to continue to innovate. Likewise, as humans continue to look at the world they begin to come up with explanations for what they see occurring and how it came about. Thus religion is created and it's varieties abound. It was the first and second most successful belief system that evolved in the human mind. And, it would serve them very very well for much of their history. Religion not only supplied authority and law but that authority also supplied the ability to free up time to work on greater task multiplicity. The emergence of religious law is an important one for us today as it dictates many of the vestiges of law that remain in non-theist governments such as the United States today.
The next great advancement occurred with the creation of iron and later the creation of steel. Like bronze, these metals increase the effectiveness of tools (and weapons) and thus decrease the amount of time needed to focus on making more tools (and weapons) freeing up humans to give rise to further different advancements and further task multiplicity.
Language receives a counterpart around between 6,000 and 4,000 years ago. The increase in trade caused by the increase in task multiplicity and the increasing numbers of people working in fields other than those producing food, require a system of documentation for this trading. A person wants to get their fair share in trade. To be tricked into or to mistakenly receive less than they give is massively detrimental in a competitive world. Math arises in tandem to deal with trade as does the concept of coinage as a universal transfer unit.
Trade for others' excess goods further increases the ability for people to spend less and less time trying to merely survive and more and more time working on other tasks. It is worth noting that the evolution of early Europe and the Eastern Asia are largely secluded from one another, yet interact between the Middle East where all cultures seem to mesh. Culture, yet apparent as early as cave drawings and oral tradition, also takes a step forward when it incorporates into written language in a complex manner roughly between 3,500 and 4,000 years ago. The first novels begin to appear around 3,500 years ago with epics we still know today such as Gilgamesh and Homer's Odyssey and Iliad. These tales seek to explain the world and in many ways to advise on the way one should live. They, in short, teach lessons. While in the past lessons were taught through song and dance as well as oral tradition, new found lengths of time for the human elite made a niche for more time consuming (to write and read) works.
Following with these epics began philosophy. Socrates, Plato, Aristotle in the Greek world for example. And Confucius and his counterparts in East Asian cultures. All appeared at roughly the same time approximately 2,600 to 2,300 years ago. Elite humans now had the time not only to think about complex processes in the world, but also to write and read about them. It isn't a surprise then that the Aristotelian Method arose from this time period. A precursor to many branches of scientific research today, it asking questions and seeking out results as a means to solve problems or mysteries. (In his case, he attempted to find the most useful form of government by looking at dozens of governments across the ancient world and comparing their assets and flaws.)
Human philosophy, thought, invention, trade, and math continued to grow by leaps and bounds throughout the ages of the Greek and Roman Empires - between roughly 2,600 and 1,524 years ago. Western history dictates that the fall of the Roman Empire in 476CE marks the end of this period and the beginning of the "Dark Ages". Indeed it was "dark" insofar as advancement in Europe during this time, but in the Middle East, advancement continued to thrive. This specific period of time, "the Dark Ages", is important for one major reason. With the fall of the Roman Empire (which was progressive over centuries, incidentally) the Western World lost much of their "elite", those who were vastly higher up than the average person and who could bring about advancement because they did not have to work at a subsistance level. Much of Europe, for centuries centralized around Rome and later Constantinople. With this centralization gone, all of the amassed ability to not have to work for subsistence by and large went with it. Trade all but ceased with the Eastern World. Cities focused inwards and localities retook control from the vestiges of Roman influence. As with all things, this did not happen over night, yet had been happening since before the fall of Rome and well after it as well.
The only common thread for much of Europe during this time was the Christian Church. It remained the only source of "elites" on a level such that Rome and Greece had seen. It became for a time the only group which could profligate or sponsor advancement. Such advancement was seen in theology and philosophy (St. Jerome for instance wrote the compendium "The City of God", a gigantic set of works codifying Christian belief while negating pagan ritual of Roman descent -- with the tone of the fall of Rome throughout).
It wasn't for another 1000 years or so before the leaders of the localities of Europe were able to stabilize and return to the "elite" status of Rome and Greece. Nation-states gained power again and even began to rival the (now) Catholic Church (the Christian Church having split into two pieces some time earlier). On occasions kings would even exert influence over the Pope, while at other times the reverse was also true. Regardless, the "elite" vacuum created by the fall of Rome was repaired by approximately 700 years ago. The reemergence of an elite made it possible again simultaneously for new advancements beyond those of Rome and Greece to begin to emerge. And, emerge they did, in Italy first. It spread slowly northward encompassing much of Western Europe within 200 years. This is the period which we call the Renaissance.
Great advances in music, art, medicine, trade, philosophy, writing, and alternate forms of religious belief rose rapidly during this period. The Protestant Reformation occurred, challenging the Catholic Church as never before. New bodies of religious power arose: Anglicans, Lutherans, Presbyterians, etc. All were negations of previously held religious ideas about how the world was, should run, or came to exist. All came about because people had the time now to think about the teachings of the Catholic Church which had remained mostly unchallenged during the "Dark Ages" and come up with new conclusions about their validity.
The Renaissance led to the creation of a "Middle Class". That is, for the first time in the world, there was a large group of people who did not need to work towards subsistence. They were not as well-off as the "elite", but they too would add an important contribution to the world only 300 to 200 years ago. Middle class farmers, those who needed to farm, but had some free time began to create advancements in farming. The Agricultural Revolution occurred and the yield of crops increased drastically with new farming techniques including specifically crop rotation and other types of soil management as well as better seed harvesting. (The particularly fair weather during this period of history did help in a great deal to push this advancement along.)
The Agricultural Revolution spurred the even greater expansion of the Middle Class until it encompassed (today) some 3/4 of many countries. These people in turn many times were able to move to cities and take non-labor jobs. Manufacturing was stimulated and the advancement of manufacturing exploded with the First Industrial Revolution between 300 and 150 years ago. Mass production of goods was now possible in factories in large cities such as London, Manchester, Paris, Hamburg, Philadelphia, and so on. Western Europe thrived immensely and would see an even greater explosion of innovation with the Second Industrial Revolution between 160 and 85 years ago (ending with the beginning of World War I). The gasoline engine was created, thus producing the largest growth in task multiplicity that the world had ever seen up until then.
Populations in the Western World boomed to their greatest heights and at the greatest speed in history not leveling off well into the 20th Century. As populations boomed, so did industry, and with it innovations arose across the board. For the first time the Western World had the weapons, populations, and transportation that it needed to engage in massive assaults. A powder keg was ready to explode. The German nation exerted its desire to expand first. A small issue (the assassination of Austrian Arch Duke Franz Ferdinand) led to the drawing into war of all of the major Western Powers. Prior to this event, a series of alliances made around the start of the Second Industrial Revolution (a period when innovation caused demand on territory to slacken, but which increased again with the increase in population, the unification of nations like German and Italy, and the rise of "national pride" or nationalism.) It is worth noting that nationalism is simply pride -- a means of motivating your allies to further strengthen yourself and the "elite" which had been seen throughout history, but that it had not yet been seen on an international stage as a war between true and powerful nations.
World War I came out of, in short, a series of alliances and the demand for resources to support a burgeoning population. The period which ensued after it (the "Roaring 20's) showed the further gains of the post-Second Industrial Revolution world. It is worth noting that during this time the world economy appears for the first time. That is, that all economies of the world are so intertwined that that which effects one effects all economies, whether that effect is good or bad. In the case of the next decade, bad would be in store. The Great Depression swept across Europe and North America because of a mismanagement of World War I war debts primarily. The dissent caused by the Great Depression caused the idea of Socialism to spring up in much of Europe and the United States. Likewise, it brought to power Adolf Hitler in Germany who rallied the German people behind the idea that (essentially) certain groups of people (Jews, gays, etc.) were the reason for Germany's involvement in the Great Depression. He convinced the German people that to become powerful again they must again take land. In the same sense as World War I, Germany attacked and conquered most of Europe. The United States, an up and coming world power, had the population necessary (because of the land and resources they had) to push back the Germans and end the war.
While all of this may seem like a history lesson, it also marks advancements of human evolution just the same as all in antiquity and pre-history that were previously mentioned. The end of World War II creates two new world powers -- superpowers -- the United States and the Soviet Union. These nations will now contain the "elitist" of the elite of the world. And, therefore from here the greatest advancements of human evolution will be found.
A period marked from the end of World War II in 1945 until approximately 1991 with the fall of the Soviet Union and the end of the competition between the U.S. and the Soviet Union (known as the Cold War) is interesting on several fronts regarding human evolution. First and most important is that the United States and the Soviet Union differed in their usage of the Middle Class. The United States had a much larger middle class than the Soviet Union, and when push came to shove, that became to tipping point of the Cold War. Simply, the US bankrupted the Soviet Union in its attempt to out-advance the United States.
This period of time marks a key moment in history, similar to the creation of oral language, written language, the Renaissance, and the Industrial Revolution. The Computer Age begins. For the first time in history humans are able to export mental processes onto another being (in this case a non-sentient one-- the computer). This frees up human thought greater than anything in its past. Humankind can now design things to think for it. The human ability of task multiplicity increases exponentially, nearly hyper-exponentially. When research can be conducted without the use of human brains, numbers crunched without help, and accuracy of results nearly perfected, humans have been able to create again something that allows them to do something that they could not do before. It is in league with the gas-powered engine and transportation or agriculture, with bronze and iron tools and their durability, etc. back and back to the beginning of humankind.
There is one final important jump in human evolution to date. The biggest flaw of the Computer Age (1945-1991) was that information though attainable was neither easily storeable nor easily transmittable (nor early on even readable with the use of punch-cards). Data could exist in London but one in New York could wait months to receive it or else have to do without. The next major advancement deals with this problem and began very early on in the Computer Age, but did come to a head until after computers became mainstream and easy to use. At this point, the effectiveness of the computer had increased so dramatically that the necessity of a means to store and transmit data became that much more pronounced.
Storage solved itself incrementally as the computer evolved. The advent of the personal computer and more specifically the rise in the popularity of the PC in the late 1980's and early 1990's intensified the inherent demand for the ability to transfer information. Thus the Internet Age was born less than twenty years ago. The ability to transmit information worldwide in an instant was born. The world became more interconnected and the excesses of each were more easily transmitted between partners. Trade make the elitist of the elite even more elite. The Internet Boom was rightly named, as the tech sector rose from nothingness, ostensibly, within a few years. And, while the boom would bust a few years later, the Internet Age would continue.
Theoretically the Internet Bust gives rise to the Second Internet Age, the rise of fiber optic high speed data transmission its hallmark, yet as that period has only existed widespread for approximately 3-6 years and is still growing, it is as of now impossible to tell where the Second Internet Age (Web 2.0 if you will) will take human evolution.
In the end, human evolution has tended towards one thing, finding ways to advance oneself over the rest. Groups, then tribes, then cities, then city-states, then kingdoms and empires, then nation-states, then nations, then international coalitions, have risen to help this process. Humanity evolves out of a necessity to pass on ones' genes more successfully than the next. It is animalistic from the core of our being and from the beginning of our species. And, as one can see, based on the history of our species so far -- separating ourselves from the rest of the world's species by a written language, theories of existence, the creation of devices which will think for us, and the profligation of acquired information globally -- it's been very successful.
What will the future hold?
If the pattern holds true, we as a species will find ways to remove the human from food acquisition. They will continue to grow as a population. Thus war will continue on greater and greater a scale. And we will outgrow this planet. If none of these concepts (or vast numbers of others) do not spell the end of our species, it will be an interesting ride for sure.