Human

The Human race is a bipedal, sentient species with a moderate-development space faring civilization. Their original home world is that of Earth, third planet of the Sol System.

Background
Throughout their existence, Humans have developed their civilization by engaging in food production on a larger scale, developing language, developing religion and political philosophies and exhibiting telescoping technological and infrastructural development. They were studying the stars long before they were able to travel out of their atmosphere. After succeeding in space colonization, the human race was able to terraform and inhabit other planets besides Earth, but the human race is under pressure due to the discovery of the caste-driven Covenant after several centuries of space travel. The total population at the end of the war is unknown. The Homo Sapien Sapiens were believed to have appeared in Earth's fossil record between approximately 100,000 and 200,000 years ago (there was another subspecies of Homo Sapiens, Homo Sapien Idaltu; this subspecies became extinct, but was believed to have lived as long as 160,000 years previous). While the exact origin of humanity is a hotly contested paleontological debate, it is likely that the first humans evolved from a genus of upright ape-like hominids called Australopithecus (i.e. Australopithecus). The current human race is not the only humanoid species known to live on Earth, but the Homo Sapien Sapiens is believed to have either displaced or merely outlasted all other branches of the genus, including Homo Neanderthals and Homo Sapien Idaltu. Homo Sapien Sapiens usually stand 6' tall, though this varies depending on nutrition, genetics and other factors. Members of the species, like some Covenant species, are four-limbed and bipedal which means they walk upright on two legs and use their arms and hands (including opposable thumbs) to hold and manipulate objects such as tools.

The development of human civilization as humans recognize it today started from the ability to harness the growth cycle of plants, producing edible food-energy in a systemic fashion. This time is referred to as the Neolithic Revolution, which occurred first on Earth over 10,000 years ago and soon spread to disparate human groups. The stability that came from systemic agriculture allowed for more permanent settlements and the development of ever-more-complex tools to further benefit the members of the species.

Innovated toolmaking and the domestication of other species on Earth gave human populations greater and greater power to expand their populations, and trade ensured the diffusion of new technologies to adjacent groups. These exploding populations led to the formation of the first genuine civilizations over 8,000 years ago. The sites of such early cultures are believed to have formed in Southwest Asia and Asia Minor, and appeared elsewhere soon after. The infrastructure of civilizations continued to expand and grow in complexity as innovative technologies and larger populations allowed for increasing food-energy availability. Economic, political, scientific and religious advancement continued to quicken as this species was able to automate many tasks in the Industrial Revolution.

This automation gave birth to the Digital Revolution, in which computing machines allowed scientific discovery and technological development to accelerate with explosive speed. Larger urban centers and tools for civilian and military uses were able to develop, as were more modern economic and political systems. As these systems developed further, the species was able to enjoy longer, more pro-creative, and more comfortable lives, virtually impervious to other creatures from whose midst they sprang. Thus-unchecked, human population growth eventually led to the presence of several billions more humans on Earth than could be comfortably sustained, ultimately leading to a high demand for humans to expand out-world.

Development of Civilization
According to the Darwinian evolutionary theory, humans evolved from primates somewhere in East Africa, in which humans started forming Hunter-Gatherer societies during the first hundred thousands years of existence. Highly mobile, they quickly spread to almost every major land formation except Antarctica, and quickly became the dominant creature on the planet. Approximately 10,000 years ago, human society began to emerge in the form of civilizations, featuring forms of farming, fishing, mining, metallurgy, and creating laws, language, and religions - often radically different depending on region - though all would share several basic fundamental aspects. The use of metallurgy for military weapons and defenses allowed these cultures to spread and conquer other lands in the name of their own, ultimately leading to the dominant rise of European nations and, in turn, to intercontinental Euro-Imperialistic colonies. Effects from the political schisms that these nations would later have with their own colonies however would have remarkable long-term ramifications for the course of mankind. Ramifications that earlier ages of humans could have never imagined, as the concept of democratic rule by Constitutional Law over the long established systems of centralized government monarchy would slowly gain momentum.

18th-20th Century
The 18th through 20th centuries were times of drastic change for countries known as the "Industrial Revolution". As an unintended result of major political and economic ramifications due to the rise of constitutional governments and refined capitalist resource management techniques, important inventions such as the automobile, electrical devices like the radio, and aircraft went into widespread use at previously unheard of rates for human innovations. Revolutionary progress in humanity's understanding of medicine and chemistry was also being made during this era of turning points. Such important chemical engineering advancements included anesthesia which dramatically enhanced all surgical practices, and plastics that could cheaply fulfill an enormous amount of material roles (with the better preservation of food being one of its greatest functions). Prior to such chemical and medical advances, average humans at the beginning of this time span could expect an lifespan of approximately 45 years, but towards its end, thanks to the introduction of antibiotics and other medicines combined with better food production and preservation, the age-old scourge of widespread plague and starvation was becoming virtually a thing of the past, and enabling people to live well beyond 80 and even into 100 years of age.

Essentially, Mankind was growing ever more efficient in how it applied itself to previous sciences and arts, and the art of the military would prove no exception to this pattern. There would be a rapid change in armed conflicts, starkly different from the primitive melee-oriented wars of the past; after 2 massive wars within the first 40 years of the 20th century, humanity saw the invention of such technologies as superior firearms and automatic weapons, radar, tanks, missiles, jet engines, and ultimately the atomic bomb, which became the most powerful weapon then known.

In the next 60 years the superpower nations of the United States of America and the Union of Soviet Socialist Republics (eventually renamed the "Russian Federation") became highly competitive, leading to a period of military and cultural tension known as the "Cold War"; by which the lethality of humanity's relatively new warfare technologies would be further refined upon in their destructive potential and precision, complimented with ever evolving battlefield doctrines and tactics as both nations sought to intimidate the other. In the 1950s, the Soviet Union launched the earliest satellite and sent the first human into space, officially making humans space faring. The United States launched the first human to land on the moon, and eventually surpassed the Soviet Union's space faring and military production capabilities, leaving their doctrines as the ones that would heavily influence the UNSC in later centuries.

Additionally, with the creation of computers and the Internet in the late 20th century, achievements from that era would dramatically revolutionized communication and data processing, further streamlining mankind's rate of technological progress. World politics also changed, with the early history of the United Nations beginning during this time period. The religiously neutral nature of many of these constitutional style governments also saw a relative diminish of the influence ideological dogma had upon a society, with scientific and logical explanations for phenomena and methodology rising in importance, although religion would remain a staple of human societies. In the later end of the 20th century, satellites were now using solar energy over primitive battery sources to power itself (as seen with earlier models) thus leading to a very long lifetime. And with this, satellites saw a much more massive and broader usage as means to send and retrieve data and communications, and additionally a method of navigation to both normal civilians and as well as military usage. Although today much of the technology used during this time are disregarded as "Primitive" they were all somehow a precursor to all of today's current technology used by the UNSC.

Colonization and War


The species was able to explore the space immediately surrounding their home planet in the 20th century, as the population began to advance beyond the capacity of the planet to comfortably sustain their civilization. The subsequent conflict over resources, economics, religion and politics on Earth gave way to numerous wars. Furthermore these tensions put great pressure on the species in the beginning of the twenty-third century, and the transnational organization that became the United Nations Space Command engaged in more frequent space colonization and sought to represent the entire species, even though no one state ever previously ruled the entire human race. The development of Slipspace travel in 2291 helped the UNSC engage in spreading the human race beyond their home solar system, relieving the serious ecological pressure on the home world.

Simultaneously, this expansion was also to usher in promising new opportunities for humanity, as some of these colonies, such as planet Reach with its bountiful titanium deposits, could offer abundant stores of raw materials that may had otherwise been considerably unique and scarce on Earth. With the initial advent of interplanetary trade driving down the costs of what may had once been an expensive implementation of their technology - such as the forging of space-worthy ships and naval vessels - the effects from these carefully implemented first colonization projects helped to ensure that interstellar trade, travel and communication were to be more commonplace amongst the general populace in the ensuring centuries, eventually granting humanity the capacity to expand to hundreds of worlds and establish colonies at enhanced rates.

The species as a whole was finally pushed into major conflict, when, after several centuries of spreading throughout many solar systems and inhabiting hundreds of worlds, they discovered the violent, genocidal, theocratic Covenant and were forced into the war covered by the Halo series. As the decades-long war wore on, the human species gained the reputation as a worthy adversary against the Covenant, despite the fact that they were technologically and numerically the Covenant's inferior.

Humans have been able to show great bravery when facing great odds. Some of the members of the Covenant wonder why the Hierarchs had refused to allow the humans to join them, as they had been able to hold steadfast even when outmatched in almost every way. However, despite great courage and brilliance, the future seemed dark for the survival of the human race as the Covenant continued to wipe out their colonies, marching ever closer to Earth.

March 3rd, 2553, saw the end of the Human-Covenant War as a victory for humanity and their new found Sangheili allies - the majority of the Covenant Loyalist military having been defeated at Delta Halo by the Sangheilian Fleet, and the rest annihilated by the joint Elite-UNSC forces at the Ark.

Technology
In early stages, human technology and knowledge advanced through simple trial and error in an inefficient manner, hampering faster progress. Although humans had developed writing very early on in their history, it wasn't until the invention of printing that information and ideas could be mass-communicated in an effective manner. The development of the scientific method in later conjunction with improved and more efficient capitalistic resource management techniques during the lessons of the "Industrial Revolution" resulted in stark accelerations in the development of technologies and the acquisition of knowledge. New technologies were experimented and explored with advanced knowledge of underlying principles as talented individuals were better organized and better supplied, allowing extremely accurate and fast improvements to be made with minimized trials and costs.

In the 26th century technology did not advance equally for every concept previously explored. The most basic technologies (such as the ballistic weaponry and the wheel) had undergone few principal changes, the explanation for this being their proven reliability over centuries of use. The technology worked and so did not require heavy alteration or major changes. Humans however did have other great advancements such as Shaw-Fujikawa Translight Engines that are capable of reaching other star systems, as well as the creation of highly sophisticated AIs that could serve to fulfill a versatile amount of roles.


 * Weapons: While still primarily based on projectiles and chemical reactions, human weapons are still more advanced than the weapons of c.2000. They come with a variety of electronic gadgets such as ammo readouts and are significantly more reliable, seldom malfunctioning. They are also generally immune to electromagnetic pulses. Still, there have been some advanced developments, such as the Magnetic Accelerator Cannon, which is extensively used on ships as well as on vehicles and ground based weapons. A similar weapon, the rail-gun, was experimented with c.2000. There have been developments in energy weapons such as the Spartan Laser and the experimental pulse lasers used on UNSC Prowler. Although some of these breakthroughs could have been because of captured Covenant technology, humans have previously used laser technology.  Humans may have a good understanding of particle beam technology but have yet to utilize it in their weaponry. One of the largest breakthroughs came in the mid 20th century where humans discovered that nuclear fission can be used as a weapon to cause a large explosion. Nuclear warheads are seen in many missile installations and UNSC warships.


 * Vehicles: Though human vehicles still rely on crude wheeled motion for locomotion, UNSC vehicles are still extremely advanced, incorporating high-strength materials with precision engineering to improve mobility and durability, while often mounting a variety of weapons or equipment to increase their flexibility. Most have switched from fossil fuels to hydrogen-fuel cell engines or at the very least use hybrid-electric engines for enhanced fuel efficiency.


 * Air Vehicles: Most UNSC aircraft are designed with Vertical-Takeoff-Vertical-Landing capabilities, using adjustable jet engines for lift and thrust. It is possible that some incorporate Lifting Body principles.


 * Medical advances: The use of Sterile Field Generators means that surgery is not only safer to perform, with a greatly reduced risk of infection, but is also able to be performed in the field. Combat personnel also use biofoam, an expanding semi-organic compound that fills and pressurizes a wound, numbing it at the same time.


 * Space-Faring: With the advent of Slipspace engines allowing faster-than-light travel, the UNSC was able to expand well beyond the confines of the Solar System, colonizing a number of worlds. UNSC freighters transport food and goods between colonies, while UNSC Navy warships protect trade routes from pirates and defend colonies from enemy assault.

Population
It is known that in the 22nd century, Earth was deemed overpopulated, jump-starting the colonization programs of the time. The final population of the species after 25 years enduring the Human-Covenant War is unknown. At the beginning of the Human-Covenant War, the population would be estimated at around 58.074 billion. The population of Earth itself after the Human-Covenant War is mostly ambiguous. However, prior to the assault its approximated that out of 12 billion on Earth, 200 million people were UNSC soldiers.

Explanation
2525 - 1999 = 526 years. The population in 1999 was 6 billion. The population has risen at a rate of roughly 99 million people per year and this may increase over time given complex economic circumstances in evaluating birth rates versus death tolls. Given that the current estimated rate more or less holds however; 526 × 99 million (1.67% each year) + 6 billion = 58.074 billion humans on Earth and elsewhere throughout UNSC space by the time of the events of the Human-Covenant War (provided that progress in medical understanding has further extended average life expectancy however, the final population total is likely to be higher). Note that this is only a rough estimation, and does not take into account potential demographic shifts (in which nations show a tendency to harbor significantly reduced birth rates after they become fully developed in exchange for living longer), nor does it take into consideration the death toll on account of wars between circa. 2000 and the 26th century.

There exists another considerable fallacy with this method of estimation; typically human population growth is not linear but exponential (i.e. the amount of growth per year increases each year). The current estimated world population growth is 1.17% per year. Once again, potential demographic transitions of each individual population can scarcely be factored. However, based on the fact that in 1999 the population was 6,000,000,000, then were it to increase by 1.17% per year for 526 years, we can be predict the population of 2525 to be at around 272,503,288,26, or 272.5 billion. In terms of population density, if humanity has colonized about 800 planets, that's about an average of 340 million people for each planet.

Anatomy and Physiology
Humans are mammalian in design and closely related to other dominant apes on the planet Earth, meaning that they are warm blooded and give birth to live offspring. They have five fingers, one including an opposable thumb, which a few covenant species do not have and was a major part in helping humans dominate on earth. Unlike Elites, their circulatory system only has 1 heart and red blood due to the iron based hemoglobin of humans. They have two lungs which breathe mainly an oxygen based atmosphere. Externally they have more hair than most covenant species but not nearly as much as Brutes. They have eyes which are not peripheral, and additionally have a poor sense of hearing and smell. Along with that, humans are external breeders as compared to elites who are internal. They are omnivorous meaning that they will eat both meats and vegetables. Their bone structure is much different than a few covenant species and have more bones than most they have a large calcium deposit, allowing them to be a perfect target for The Flood. Muscle-wise they are weaker, if untrained, than a majority of covenant species including drones in which they have they ability to pick up humans and fly while holding one. Physical conditioning can still negate this somewhat, as even a standard UNSC marine can be witnessed flipping a turned over vehicle.

Connections Between The Forerunners and Humans
"You are the child of my makers. Inheritor of all they left behind. You are Forerunner!" -343 Guilty Spark to Master Chief.
 * A common theory amongst the fans is that the Forerunners are ancient ancestors of Humanity. Examples of possible descent include the fact that only humans can take the the Index from its resting place in the Library, as well as comments made by 343 Guilty Spark during Halo: Combat Evolved and Halo 2. In both games, the Monitor conveys confusion about the ignorance the humans have regarding the Halo array . Halo 3 seems to give the most evidence for the theory of humans being Forerunner descendants. 343 Guilty Spark tells the Master Chief:

In Halo: Combat Evolved, 343 Guilty Spark refers to human history as "a record of all our lost time", giving further evidence that humans are possible descendants of the Forerunners.


 * The High Prophet of Truth also tells Sergeant Major Johnson: "Your Forefathers wisely set aside their compassion. Steeled themselves for what needed to be done. I see now why they left you behind. You were weak. And gods must be strong."
 * However, the recent web comic that included the character N'chala makes this theory less likely. It seemingly disproved the theory with the combination of the Server 05 message from and the Iris viral campaign and the Terminals of Halo 3 explaining that the Forerunners discovered humanity on a planet in a "perilous location beyond the line" (possibly meaning that Earth was outside of the Forerunners' protection. The Librarian built a portal to the Ark before Didact fired the array, ensuring humanity's survival of the Halos and the Flood. As shown with the Bestiarum the Forerunners worked to categorize species that they found. Humanity then, was not created by the Forerunner.
 * Another theory (one supported by the Halo 3 Terminals) is that the humans became the inheritors of the Forerunner empire and technology because the Forerunners passed the Mantle of Guardianship down to humanity, as it was passed to them, presumably from the Precursors. (see Reclaimer for more). Though this will likely not happen again.
 * Another similarity is on the level Sacred Icon, when you deactivate the plug locks then a holographic hand comes up and it looks just like a human hand. This implies Forerunner technology was implied for Human usage.
 * During the events in Halo: Contact Harvest, Covenant religious vehicles traveled the edge of Covenant-controlled space and discovered a planet that was covered with Forerunner "Reclamation" glyphs. A Brute Chieftain known as Maccabeus (uncle of Tartarus) landed on the planet (Harvest) and was, at first, friendly to the humans. It wasn't until a shot rang out did things turn bloody. Later, a report of the planet's glyphs was sent to the Vice Minister of Tranquility (Regret). He took the information to the Minister of Fortitude (Truth) and they went to see the Oracle (the Forerunner AI in the Dreadnought). Upon activation of the Oracle, the AI exclaimed, "FOR EONS I HAVE WATCHED. LISTENED TO YOU MISINTERPRET. THIS IS NOT RECLAMATION. THIS IS RECLAIMER." After those words, the glyphs in the report were shown and they began to transform shape until a crude image of a human appeared. The Oracle adds, "AND THOSE IT REPRESENTS ARE MY MAKERS. I WILL REJECT MY BIAS AND WILL MAKE AMENDS. MY MAKERS ARE MY MASTERS. I WILL BRING THEM SAFELY TO THE ARK." After that, the power conduits aboard the Dreadnought short circuit as several frying, dead Lekgolo worms fall out of the spaces. The Dreadnought powers down. Truth, believing that the humans were actually Forerunner, believed this information could destroy the foundation of the Covenant and, with it, his power. Upon being promoted (through blackmail) to High Prophet, he used his power to set out a massive religious genocide against the humans.


 * "Child of my enemy, why have you come? I offer no forgiveness; for the fathers sins pass to his son."

- The Gravemind speaking to the Master Chief, acknowledging a relationship between humanity and the Forerunners.