What is Human: Definition and 893 Discussions

Humans (Homo sapiens) are the most abundant and widespread species of primates, characterized by bipedality and large complex brains enabling the development of advanced tools, culture and language. Humans are highly social beings and tend to live in large complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Curiosity and the human desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of knowledge.
Humans evolved from other hominins in Africa several million years ago. Although some scientists equate humans with all members of the genus Homo, in common usage it generally refers to Homo sapiens, the only extant member. H. sapiens emerged around 300,000 years ago, evolving from Homo erectus and migrating out of Africa, gradually replacing local populations of archaic humans. Early humans were hunter-gatherers, before settling in the Fertile Crescent and other parts of the Old World. Access to food surpluses led to the formation of permanent human settlements and the domestication of animals. As populations became larger and denser, forms of governance developed within and between communities and a number of civilizations rose and fell. Humans have continued to expand, with over 7.8 billion humans occupying almost all regions of the world in 2021.
Genes and the environment influence human biological variation in visible characteristics, physiology, disease susceptibility, mental abilities, body size and life span. Though humans vary in many traits (such as genetic predispositions and physical features), two humans on average are over 99% similar, with the most genetically diverse populations from Africa. The greatest degree of genetic variation exists between males and females. On average, men have greater body strength and women generally have a higher body fat percentage. Females undergo menopause and become infertile decades before the end of their lives. They also have a longer life span in almost every population around the world. The division into male and female gender roles has varied historically, and challenges to predominant gender norms have recurred in many societies.
Humans are omnivorous, capable of consuming a wide variety of plant and animal material, and have used fire to prepare and cook food since the time of H. erectus. They can survive for up to eight weeks without food, and three or four days without water. Humans are generally diurnal, sleeping on average seven to nine hours per day. Childbirth is dangerous, with a high risk of complications and death. Both the mother and the father provide care for human offspring who are helpless at birth.
Humans have a large and highly developed prefrontal cortex, the region of the brain associated with higher cognition. They are intelligent beings, capable of episodic memory, flexible facial expressions, self-awareness and a theory of mind. The human mind is capable of introspection, private thought, imagination, volition and forming views on existence. This has allowed great technological advancements and complex tool development possible through reason and the transmission of knowledge to future generations. Language, art and trade are defining characteristics of humans. Long-distance trade routes might have led to cultural explosions and resource distribution that gave humans an advantage over other similar species.

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  1. C

    How space works:Why does an asteroid crush a human in space?

    I hve a question: IF there is no air resistance or ANY type of resistance in space, then how come an asteroid or fast moving object can crush a persons face in space (like in the movie: Gravity) My logic is the following: If you imagine a spring extended in space, and a fast moving ball hits...
  2. S

    What changes does human body exert when it enters a room ?

    I am making home automation model and I have few sensors installed to sense some changes in the environment to detect any changes. So these sensors provide me data , but I want to know what changes does Human body exerts on the environment it enters, so that I can install those sensors which...
  3. S

    What is the strongest magnetic field a human could survive?

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  4. T

    Human powered hydraulic exoskeleton

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  5. F

    Human Energy, Work Done and Declining results

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  6. G

    Bacteria in the human body: when we die and when we are born

    It is said that around 90% of the cells in a human body are symbiotic bacteria living thanks to us. When we die, do most of them also die? Or do they manage to survive without us and find a new 'home human'? And opposite, when and how do we get all those bacteria after conception? Do we get...
  7. jerromyjon

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  8. caters

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  9. M

    Is Deja Vu the Brain's misinterpretation of Spacetime?

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  10. B0b-A

    Any evidence bacteria can exist within mitochondria in humans?

    I heard a claim bacteria can exist within human mitochondria, is there any evidence that is true ?. mitochondria"']https://www.google.com/search?q="bacteria+within+mitochondria"[/URL] only gets one hit, and the examples given are not human.
  11. P

    Effortless actions of a human being

    Hey guys, the question for this thread is, how can I find out what the heaviest object an average human can move effortlessly is? and by that I mean literally effortless to the point where it requires little to no force, even less than easy to move an object. One example I could give is picking...
  12. G

    Power of human Heart and Brain

    If heart forces 4 litres of blood per minute and blood pressure is 125 mm of Hg column and we consider pulse rate as 60 beats per minute then by calculation power of heart comes as approx. 1.111 watts. If I consider the person is just lying down and obviously brain is also active . My question...
  13. B

    Understanding the Human Eye: Exploring Focal Length and Retinal Distance

    I never could understand this: the lens focuses light onto the retina so shouldn't the distance between the lens and the retina be the focal distance? It does not seem to be the case while I was trying to look around for the answer on the internet. And since light is focused on the retina, the...
  14. Q

    How much effort to lift a human being?

    What size propeller is required to lift a 180 lb person 30ft into the air consistently? Also, how powerful would the motor have to be to lift itself, the propeller, and person?
  15. Q

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  16. Astronuc

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  17. Y

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  18. L

    Relative Body Angles of a Human Moving Through Space

    Homework Statement Say a human is moving through space with constant acceleration due to gravity. There are no external forces/torques on the body other than the force of gravity. The person applies an internal torque at some joint, let's say the knees, so that they bend. Assume the rest of the...
  19. J

    How did human female breasts evolve into such an important sexual organ?

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  20. fluidistic

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    Apparently the retina of humans covers about 65% of the surface of the interior of our eyes. But most light is focused around the fovea centralis and if it isn't focused around there, we lose resolution. I understand that at night it's better not to focus too close to the fovea centralis but...
  21. J

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    There are a lot of books and videos that can teach you how to do math in your head. does any of it really work. Is there a certain book or video that you would recomend
  22. D

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  23. L

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  24. C

    Wow, human powered ferris wheel

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  25. Calpalned

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  26. haael

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  27. B0b-A

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  28. A

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  29. G

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  30. B

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  31. TrueGormagon

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  32. T

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  33. Pythagorean

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  34. DiracPool

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  35. M

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  36. R

    Can a Human Survive in a Vacuum Chamber for Several Hours?

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  37. T

    What would happen if I was standing in the LHC

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  38. Prashasti

    What causes mutations in the genetic material of Human Immunodeficiency Virus?

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  39. I_am_learning

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  40. B

    How imperfect is the human machine

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  41. J

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  42. M

    Does human body capacitance change when floating vs. standing?

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  43. A

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  44. aditya ver.2.0

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  45. K

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  46. Keith

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  47. T

    Is the current human species the result of artificial selection?

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  48. Q

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  49. S

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  50. davgonz90

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