“”MAN, n. An animal so lost in rapturous contemplation of what he thinks he is as to overlook what he indubitably ought to be. His chief occupation is extermination of other animals and his own species, which, however, multiplies with such insistent rapidity as to infest the whole habitable earth and Canada.
|—Ambrose Bierce, The Devil's Dictionary (1911)|
Human (scientific name Homo sapiens sapiens) is the common name of the primate species also known as the East African Plains Ape, the dominant tool-using species on the third planet (counting outwards) of some backwater minor star.
On the rocky sub-planet they inhabit, which they call "Earth," humans have built cities (hives), engaged in writing for at least the last six thousand orbital periods, and have grown to a population of 7 billion individuals. Twelve humans have walked on the planet's primary satellite, and at least three humans are maintained in orbit around Earth at any given time. Humans have sent robotic probes to every major body in their Solar System, and sent four probes out of the system altogether.
In appearance, most humans have a bilateral symmetry built around a stack of bones called a spine, that some may lack, with most of their sensory organs concentrated near their single brain in a pod mounted at the top of this spine. Humans using a language originating from the part of Earth known as "England" refer to this pod as a "skull." They have evolved to balance on two of their four limbs, leaving the other two free to manipulate their environment.
 General biology and reproduction
Healthy human bodies maintain a constant temperature of roughly 310 kelvin (one kelvin is equal to 1/100 of the difference between the temperature of freezing and boiling H2O at their planetary surface, the scale is then reckoned from absolute zero). They lack natural insulation over most of their skin, but they compensate by fashioning for themselves artificial insulation as appropriate for whatever environment they choose to inhabit. They reproduce sexually, mixing and matching their 23 pairs of chromosomes in the process. The female retains the fertilized egg inside her body until the offspring is mature enough to survive in the world with somewhat less intensive care. However, after ejecting the infant in a difficult ordeal (on account of the size of a human baby's head compared to the passages through which it must be delivered), the female human sustains her offspring for some time as all female mammals do, with secretions produced by glands mounted prominently on her upper body.
 Continued survival
Despite having by far the largest population of any known primate species (about seven billion scattered throughout all seven continents, and under most of the oceans, including areas normally considered uninhabitable), the East African Plains Ape is classified as Critically Endangered due to it being paradoxically too stupid to handle its high intelligence.
Given their rather violent history, it is somewhat debatable how well human beings will execute their often high ideals for the future. A central challenge for the human race going forward will be their ability to peacefully co-exist with one another, share their planet fairly and equally, and live up to their great potential as a species.
 What humans say about themselves
Humans who study humans are called "anthropologists." Humans who pretend to study gods are called "apologists."
Humans are "featherless bipeds," according to the great anthropologist Woody Allen.
 See also
- Behavioral modernity, which distinguishes humans from other hominids.
- List of possible human ancestors
- WikiPedia:Ulas family
- Family may provide evolution clue: BBC article about how human quadrupedal ancestors may have walked.