Human
Humans are a species of bipedal tetrapod sophonts from the planet Earth in the Sol system. Humans are primates: a group of mammals characterized by a somewhat compact torso supported by four long, highly mobile and dexterous limbs. These limbs usually allow for agile arboreal movement in most primates, but in humans the dexterity of the lower limbs has been lost in favor of plantigrade locomotion on the ground. What humans lack in speed and strength they more than make up for with endurance, resilience, and an uncanny ability to throw with great force and precision. Humans are very adept tool-users, having developed a starfaring technoculture completely independently from any other civilizations in local space.
Biology
Anatomy & Morphology
Humans are vertical bipedal tetrapods, with one set of manipulatory forelimbs at the top of the torso and a pair of hindlimbs at the bottom of the torso used for terrestrial locomotion. Like most motile complex organisms in the universe they are cephalized: the brain, mouth, and sensory organs are clustered together to form a head which is attached to the top of the torso by a short extension of the spinal column. Humans have an internal skeleton composed of collagen and calcium phosphate. Their vascular oxygen carrier is hemoglobin, an iron-based protein that turns bright red when oxidized. Though efficient, hemoglobin is easily damaged by carbon monoxide, rendering humans one of just three known sophont species susceptible to carbon monoxide poisoning.Humans lack almost all traces of their ancestral tails, and their recent ancestors' opposable digits only remain functional on the upper limbs. They are almost entirely without fur, only retaining a thin covering of hair across most of the body and a concentration of it on top of the head. The front of the head is dominated by a notably flat face, lacking the snout or muzzle common to most other mammals —in humans, this has been reduced to a single modest protrusion called the nose.
Human phenotypical expression is quite variable, especially concerning their skin and fur tones which range across the warm colors from rich, dark browns to very pale pinks in a variety of combinations. Although their fur is sparse and concentrated mainly on the top of the head, the texture of this fur also varies considerably from straight and wispy to tightly coiled.
Perception & Sensory Capabilities
Visual
Humans rely most on their visual sense. They are incredibly visual beings, with most of their technology and culture involving crucial optical aspects. Human visual sense is facilitated by a single pair of binocular focal eyes located just above the nose on the face, which are able to pick up motion, definite shape, spatial orientation, and color. The eyes are mobile but mostly pair-locked; they move largely in tandem to consistently produce one binocular image.Auditory
Humans are also quite dependent on their auditory sense, facilitated by a pair of vaguely dish-like external ears, one on each side of their head.Olfactory
The human olfactory sense is generally not especially strong, facilitated by a pyramidine protrusion in the approximate center of their face. This nose has a pair of spiracles that lead to a sensory chamber connected to the respiratory system.Tactile
The human tactile sense is by far their strongest. Their entire epidermis is sensitive to tactile input, though the effect is most intense in the manipulative digits at the ends of the upper limbs. Humans can usually detect the difference of a single molecular layer between two surfaces.Life Cycle
Reproduction
Humans, like most of their phylum, are gonochoric and use a variation of the common "appendage and socket" morphology for internal fertilization. The human species has two sexes[note]: male and female; with some rare individuals naturally exhibiting sex characteristics of both (though never producing both sets of gametes). With the advent of genetic engineering, however, a small number of humans have opted to become functional simultaneous hermaphrodites in various configurations.Development
Humans belong to the "placental mammal" clade of terragenid life and as such are viviparous: offspring develop in a specialized organ (the uterus) inside the female parent which provides constant, direct blood flow between the parent and the developing embryo. Humans normally only produce one child at a time, though may occasionally produce two or more offspring under certain conditions. After a gestation period of about nine metric months, human babies are born, but remain quite underdeveloped and helpless.For the first year or so of their lives, human babies will be fed by one or both parents with milk: specialized glands on the parent's chest filter and enrich blood to produce a nutrient-dense liquid which is then secreted. This process is uncommon in sophonts, but shyxaure also exhibit this trait in a different anatomical form. From this point, humans have a continuous ontogeny, growing slowly until maturity is reached. They do not undergo periodic metamorphosis or molting; changes occur gradually and the body maintains continuity.
Lifespan
Humans undergo adolescence from about 12 to 18 metric years of age, though various human cultures have differing benchmark ages for adulthood (anywhere between 13 and 25 years of age). A healthy human has a natural lifespan of approximately 75 to 100 metric years, though modern medical technology can extend human lives considerably longer than that. The oldest living human on record is Fukuyama Matoi, a resident of Earth who is currently 349 years old.Ecology
Geographic Origin & Distribution
The human genus, Homo, originated in the eastern region of Africa on the planet Earth about two million years ago, beginning with the species Homo habilis. These primates evolved from semi-arboreal omnivores towards a fully terrestrial lifestyle, adapting a more opportunist and eventually outright predatory niche as they became more adept at both travel on the ground and tool use. Homo sapiens, the modern human species, emerged roughly two hundred thousand years ago, and quickly spread across the entirety of their homeworld.The first stages of true civilization in the human species are estimated to have appeared around twelve thousand years ago, as humans began to master the principles of agriculture and adopt a permanently sedentary lifestyle. The gathering of increasing numbers of humans in concentrated areas –that is, the beginnings of urbanization– created a snowball effect of technological innovation and globalization, leading to a fully globalized civilization around the beginning of the 21st century CE. The invention of spaceflight enabled these instinctual wanderers to spread across their solar system in the 21st and 22nd centuries, and eventually to other suns from the 23rd century onward. In the present time, it can safely be said that nearly every inhabited system in known space has at least a half-dozen humans; likely many more.
Habitat & Survival Factors
The optimal survival range in a variety of factors for an unequipped human is quite wide to begin with, but given the technology and/or resources to build said technology, humans can eke out a living almost anywhere in the universe.Sociology
Civilization & Cultural Groups
Most human-inhabited worlds, as well as their home planet Earth, are members of the United Nations of Humanity: a cohesive governmental forum that provides broad guidelines on important topics and concerns as well as moderation of international/interplanetary/interstellar relations.
Pioneer Plaque by Linda Salzman Sagan
The image humanity engraved into one of its unmanned spacecraft, in the event it was discovered by a fellow sophont species.
Archive Data
- visual (380 - 750 nm)
- auditory (20 Hz - 20 kHz)
- tactile (1 μm limit)
- olfactory
The values presented here describe the conditional limits of sustained indefinite survival. The species can survive more extreme conditions for shorter amounts of exposure.
Gravity limit
1.5 G
Pressure range
0.5 to 2.5 atm
Air mix
15% to 60% O2
Temperature range
10 to 30 °C
Radiation limit
- Gamma: 0.25 Gy
- Beta: 0.05 Gy
- Alpha: 0.0125 Gy
Great description of humans from an outside perspective - certainly made me interested to look around what these humans are up to. And as promised - happy 8th anniversary, Astra Planeta! Have some cake.
Thank you very much! Though the overall site is rather human-centric, I thought it would be interesting (and nicely unbiased) to describe humans in the exact same manner in which I've described the other sophonts. We're just as weird as them, if you think about it like that!