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. S

    Could human DNA be every type of plant, animal, or microbe DNA?

    I'm asking in order to understand if the only difference between the DNA of all living things is merely the arrangement or sequence of their letters. This is more of a curiosity question, not about sci-fi or current feasibility. Could the letters of a human DNA be reordered so it's identical to...
  2. jim mcnamara

    First pass at creating a human pangenome

    Popular science: https://www.livescience.com/health/genetics/1st-draft-of-a-human-pangenome-published-adding-millions-of-building-blocks-to-the-human-reference-genome Nature (open access:) https://www.nature.com/articles/s41586-023-05896-x A pangenome is a genomic map using extant variable...
  3. D

    B What Would Happen to the Elements in the Human Body If Teleported to the Sun?

    The human body is made up of mostly oxygen, hydrogen, nitrogen, carbon, calcium, and phosphorus. Less than 1% is sulfur, potassium, sodium, chlorine, and magnesium. If a human body was teleported to the surface of the sun, what would happen to these elements? Which ones would cease to exist...
  4. pinball1970

    Ancient Human Relative Walked Upright 7 Million Years Ago

    "The fossilized find, first uncovered two decades ago, suggests that early humans regularly walked on two feet some seven million years ago. This new analysis, published today in Nature, makes a strong case that Sahelanthropus tchadensis, a species that lived during the critical time when our...
  5. Jarvis323

    Current and Future AI Threats to Humanity and the Human Response

    There has been an explosion of discussion among experts about the evolving/growing dangers of AI and what to do about it. This debate has gone public, largely due to the recent success of generative AI, and the rapid pace of improvement. As an example, AI models which can generate images based...
  6. R

    "New" theory of human movement as described by Tesla. Right?

    Nikola Tesla, the prominent 20th century inventor, stated in his book "My Inventions" that all human movements appear to come from the will but are are actually generated from the outside. He goes on to say that this phenomenon is of incalculable vale to the human race and he urged further study...
  7. G

    Can a human calculate this without a calculator?

    my notebook says that we can rewrite the integral $$\int {75\sin^3⁡(x) \cos^2⁡(x)dx}$$ as $$\int {75 \cos^2(x)\sin(x)dx} - \int {75\sin(x)\cos^4(x)dx}$$ however, i have literally no idea how it got to this point, and i unfortunately can't really provide an "attempt at a solution" for this...
  8. bob012345

    Milestones of a human lifetime on a log scale

    In another thread the concept of how many seconds in a year came up and it made me think of putting milestones of a human lifetime on a log scale. Units are seconds. Please feel free to amend or change or just make it better. Maybe an actual plot? What strikes me is most of life is in the last...
  9. S

    Exploring Life Perspectives: Survival, Doing Good, and Continuing the Human Race

    From my point of view: 1) survival 2) do something good to satisfy your inner soul and for others. 3) help to continue the race of human being 4) and die What others think about life?
  10. M

    Is there a way to use the hydrogen in the human body?

    I recently read that there is enough hydrogen in the human body to lift 195 lbs off the ground. I know this sounds super-silly but if we ever develop nanites; could they manipulate the hydrogen and allow us to float?
  11. S

    CocaCola or Pepsi - The human sense of taste & flavor

    Just the summary as written. My own impression WAS that Pepsi Cola was a little sweeter, and Coca Cola was spicier and slightly less sweet. I do not remember my impressions of other colas. I would be interested in other details which members may tell.
  12. freelooooo

    How does Cmax decrease over time in human body? Use half life?

    I'm interested in chemistry but it's all new for me and I'm just starting out. I tried to do some calculations but got stuck... I was wondering, for example a supplement has the following values: Molar mass: 306.247 g mol-1 Tmax 2-4 hours Cmax 363.3 ng / ml Half life: 11.21 hours How do...
  13. BillTre

    Parentese, Universally Conserved Adult to Baby Human Speech

    NY Times article here. Paywalled Nature Human Behavior article here. bioRxiv preprint here. Sing-songy talk to babies has been observed in Adults of any culture seem to be able to identify baby talk in any other language. Many think that baby talk leads to more adult language development...
  14. ElectricVocaloid

    Dynamics problem (force and torque analysis) of a human finger

    I was having trouble with a physics problem (string tension dynamics) In this case I have a model that simulates the phalanges of a human finger. Each phalanx is a block of mass m1, m2 or m3 respectively. And to simplify it, consider the 3 equal masses. These phalanges are linked by joints that...
  15. PainterGuy

    Medical How does human eye decode different geometric shapes such as circle?

    Hi, How does a human eye classify any shape as a circle, square, triangle etc.? Let's focus on a circular shape. Suppose we have a circle drawn in white on a black surface. The light falls on the retinal cells. I think the light falling on the retina will constitute a circular shape as well...
  16. P

    Can the human body produce EMPs?

    I'm sure this is a strange question, but I am really curious as to whether the human body can produce electromagnetic pulses. And particularly, whether an orgasm is a type of EMP. Wikipedia says an orgasm is "a sudden discharge of accumulated sexual excitement". So is this discharge of...
  17. Delta2

    All the possible posts in PF, all the possible human thoughts

    Well since we count all possible posts , including those that have no syntax, no proper grammar or proper words, and no sensible meaning, all posts of length n are something like 100^n (I suppose we have 100 possible chars besides the letters of ordinary alphabet, including symbols like the...
  18. PainterGuy

    Can High Intelligence Truly Govern Our Emotions?

    Hi, I often hear people saying that why and how that person could react in such a way , he or she is so intelligent, so educated etc. The statement implies that if a person is considered to be intelligent or educated, he or she could control their emotions such as anger, jealousy, depression...
  19. B

    Are there Limits to Human Understanding in Physics and Mathematics?

    do you think there are biological limits to our capacity to understand physics or mathematics?could it be that in the distant future, no scientific progress could be achieved using the human brain, and we have to depend on superhuman level ai to do the work for us?
  20. L

    Does the human eye magnify objects?

    Does the human eye see things at the correct size or is there such a thing? I know one of my eyes sees things slightly smaller than the other, but ideally should the eyes biologically not magnifying or shrink anything at all?
  21. Q

    Wanting to study energy in the human body

    Summary:: Looking for a certain degree program What kind of degree would be best if I really wanted to get into studying energy within and around the human body and interactions of it between electronic signals and things like that? I am really starting to believe that our understanding of...
  22. LCSphysicist

    What is the most advanced software that simulates human behaviour?

    I have been really curious about the possibility of simulate the human's communication hability using computer language/softwares. Most specifically, i have been thinking that the most difficult part of the simulation would be to "cofide" the level of randomness+logic that the human brain can...
  23. moriah

    Unpacking the Complexity of Human DNA

    What is in our DNA that separates us from other primates?
  24. J

    A question about resistance in the human body

    Back in grade 10..,.( Oh my that was awhile back 😀 ) our electronics teacher passed around a multimeter and everyone measured their resistance ( a lead held in each hand, Fluke was set on infinite ). All in the class measured between 700K and 800K approx. All except me that is. I measured 1.4M...
  25. BillTre

    Lingusitics Great Human Genetics, Language and Culture Podcast

    I just listened to a great podcast on the explosion of human genomic data about human migration, which ties in with the spread of ancient language groups, and reveals some of past cultural practices. It is Sean Carroll's Mindscape podcast #179; David Reich on genetics and ancient humanity...
  26. gen66

    How fast does a human sized object need to move so I won’t see it?

    Summary:: How fast does a human sized object(or a human) need move so I won’t be able to see it at all if it passes right next to me? Im trying to figure out something in regards to the Flash movies/Flash series but I’m super bad at calculations and math :( Do you think that mach 2...
  27. S

    How can a human body create such effects on a freezing cold winter day?

    I was in doubt if this is the right chapter to place this thread, but it seems there are many talents just here. "we were observing from a decent distance through optics. The weather was frosty, clear, calm. When хххххх appeared from under the arch of the house (he was хххххххх to walk to the...
  28. Demystifier

    Other What are some recommended books on human irrationality?

    Perhaps psychology is not exactly a "science" in a STEM sense, but understanding human irrationality is these days important more than ever before. To beat the pandemic or the climate changes, we have to cope not only with medical and environment issues, but also with human irrationality. Some...
  29. Astronuc

    Human factors, technology and deep space missions

    When a Mars Simulation Goes Wrong https://www.theatlantic.com/science/archive/2018/06/mars-simulation-hi-seas-nasa-hawaii/553532/ The article came across my desk (computer screen). Human behavior is complicated. I'm more interested in the technical side of space travel, specifically the...
  30. ergospherical

    Human behavioural biology lectures

    I gotten randomly hooked on this lecture series by Prof Sapolsky, I thought I'd share in case anybody felt like giving them a watch or discussing some things you found interesting
  31. sciencebum

    Maximizing Boat Speed: Exploring Human Power Ratios

    In competitive rowing, the more people in a boat, the faster it goes, but what is the ratio of additional human to speed, and what is the theoretical limit? If I could fabricate a boat where each additional person added 100kilos, 100watts of power, and 1 meter of length to the wetted surface...
  32. Viky1147

    Calculate scaled down human model weight for practical experiment

    Hello, I need to scale down a human model by 1:20 i.e, i need a human model of 9 cm height scaled down. Help me calculate the weight of the 9 cm scaled down human model. Regards, Viky
  33. M

    How human strength can increase without increased muscle size?

    I know this is a hypothetical question, but we can still have a general idea for how we could do it in the future. I wonder how theoretically with good enough technology a human can achieve a super-human strength(or close to it) without large muscles or non-biological components attached to...
  34. B

    And The Actual Human Response To Keanu Reeve's Klaatu Would Be....

    A six way, all out release of humanity's entire stockpile of "engineered criticality devices" and slag the planet. The damned aliens were exterminating humanity anyway, why should they get what they want, while we go black? I'd bet money neither the movie's writers nor the extraterrestrials...
  35. jaumzaum

    The Draper point and why can't we see human radiation

    I was wondering how many visible photons humans emit in a day. I did all the calculations with the Planck's Law (it's quite easy, because in the visible spectrum and for temperatures above 0 degrees the exponential term is much larger than one, and the "-1" can be taken out of the integral...
  36. pinball1970

    Human Brain Evolution: 2 Studies Examined

    Two studies on human brain evolution/development. FIRST A new study is the first to identify how human brains grow much larger, with three times as many neurons, compared with chimpanzee and gorilla brains. The study identified a key molecular switch that can make ape brain organoids grow more...
  37. S

    Medical Is the human appendix getting smaller?

    Hello All It seems to be accepted wisdom that the human appendix is gradually getting smaller, and eventually it will disappear altogether. Is there any evidence that this is true? For the organ to get smaller generation by generation, wouldn't there have to be a selective advantage for...
  38. Doma Noemi

    Electricity in the human body -- Is there enough to power a prosthesis?

    Can we use the electricity from the muscle to power an engine (like a prosthesis)?
  39. P

    Stargazing Can distance in space be measured by human systems?

    I'm past middle age, and it seems I should have fewer questions about life and the universe than ever. I have more now. For some reason this past year or so I've been absolutely consumed with trying to grasp the immensity of the universe and distances. For whatever reason, I'm having more...
  40. PainterGuy

    Human body growth in the absence of a brain

    Hi, Does the brain control the physical growth of a human baby? I think if, for some unfortunate reason, the brain is absent, the growth would still take place normally but more like a vegetable. I don't think if the brain is absent, one can even blink the eye or move a finger. But the...
  41. N

    What is the impedance of the human body and why does it vary?

    I was researching what the total electrical resistance of the human body was and got some quite far ranging values. It seems to range from 1, OOO to 1OO,OOO ohms. Some quite elaborate ways of testing it too. Then I thought I'd just get the old multimeter out. I have two and both measured about...
  42. A

    How do human brains detect false irregularities in faces?

    Hi! So my question is: how to human brains detect false irregularities in faces? With false irregularities in faces I mean aspects of for example deepfake faces or photoshopped faces which show irregularities that are not normal to appear in an observed human face (for example weird lines...
  43. Nick tringali

    The Obstetrical Conundrum: Fontanelles & Human Birth Canals

    I want to do a project for my class on the obstetrical conundrum. Which is basically the antagonism of selective pressures on pelvic morphology. I need help to find literature. I want to know if over the course of history, if Human baby's fontanelles increased in size in order to compensate for...
  44. S

    How tyrannical is the rocket equation for a human RT to Mars?

    I was reading this: https://www.cnbc.com/2020/12/01/elon-musk-highly-confident-spacex-will-land-humans-on-mars-by-2026.html It just seems that the Delta-V requirements - especially with a spacecraft that is stocked with supplies for a few years or for the Hohmann transfer helio-orbits - will...
  45. BillTre

    The International Space Station as a Human Abode

    The NY Times, on the 20th anniversary (on Halloween) of the ISS being continuously occupies, published an article (with lots of pictures and a really cool time line) showing what the inside of the ISS is like. Duct tape on the ISS (didn't see any WD-40): Galley: Science stuff:
  46. .Scott

    Can Human Night Vision Outperform a Flashlight?

    I thought of my experiences with night vision when I happened upon this essay (Into the Night). To stay in best health, I do a two-hour, six mile walk every day. In the summer (when the days are hot) and the winter (when the days are very short), I often choose the night for this activity - and...
  47. T

    What are all the ways to grow grey matter in the human brain?

    Hi, forgot to say a thanks for all the info provided in my previous thread to everyone who posted. So what is the answer or answers to this threads question or what works?
  48. pinball1970

    Medical Oldest human tracks found in Arabian Peninsula

    From the abstract. The findings, it is argued, likely represent the oldest securely dated evidence for Homo sapiens in Arabia. The paleoecological evidence indicates a well-watered semi-arid grassland setting during human movements into the Nefud Desert of Saudi Arabia. We conclude that...
  49. anorlunda

    Pentagon plans 2024 F-16 dogfight between human pilot, AI

    Man oh man this sounds like a great stay-home-spectator-event. Better than a super bowl. But we'll have to wait until 2024. https://www.washingtontimes.com/news/2020/sep/10/pentagon-2024-fight-pilot-artificial-intelligence/
  50. Keth

    Any studies looking for a quantum bump in human photoreceptors?

    Has there been a study looking for a quantum bump in human photoreceptors. I've done some searching and haven't crossed anything as of yet.