(PhysOrg.com) -- When it comes to finding the single best tool for building, digging, grasping, drawing, writing, and many other tasks, nothing beats the human hand. Human hands have evolved over millions of years into four ...
A team of researchers affiliated with multiple institutions in China, the U.S. and Brazil has used "handedness" in chiral gold nanoparticles to enhance immune response to the influenza virus in mice. The group describes their ...
Evolutionary expert Charles Darwin and others recognized a close evolutionary relationship between humans, chimps and gorillas based on their shared anatomies, raising some big questions: how are humans related to other primates, ...
Archaeology
Feb 25, 2021
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A team of researchers from Japan, Hong Kong and Ethiopia has found a hand ax that they believe was made by a possibly direct human ancestor in what is now modern Ethiopia. In their paper published in Proceedings of the National ...
Before there were animals, bacteria or even DNA on Earth, self-replicating molecules were slowly evolving their way from simple matter to life beneath a constant shower of energetic particles from space.
General Physics
May 20, 2020
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Research by anthropologists at the University of Kent has identified hand use behaviour in fossil human relatives that is consistent with modern humans.
Archaeology
May 18, 2020
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If a robot is sent to disable a roadside bomb—or delicately handle an egg while cooking you an omelet—it needs to be able to sense when objects are slipping out of its grasp.
Engineering
Oct 17, 2017
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172
Strong fists for defending ourselves and opposable thumbs for work as fine as threading a needle—hand specialisation is widely believed to have given humans a major evolutionary advantage.
Evolution
Jul 14, 2015
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There's new evidence that shaking hands really does matter when it comes to striking the best deal in negotiations.
Robotics
May 11, 2015
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916
Much has been thrown at left-handed people—they are quick to anger, quickly scared and, with the exception of heads of state, are more or less life's losers. Much too has been bestowed upon left-handed people—they are ...
A hand (med./lat.: manus, pl. manūs) is a prehensile, multi-fingered extremity located at the end of an arm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "hand" and fingerprints remarkably similar to human fingerprints) are often described as having either "hands" or "paws" on their front limbs.
Hands are the chief organs for physically manipulating the environment, used for both gross motor skills (such as grasping a large object) and fine motor skills (such as picking up a small pebble). The fingertips contain some of the densest areas of nerve endings on the body, are the richest source of tactile feedback, and have the greatest positioning capability of the body; thus the sense of touch is intimately associated with hands. Like other paired organs (eyes, feet, legs), each hand is dominantly controlled by the opposing brain hemisphere, so that handedness, or the preferred hand choice for single-handed activities such as writing with a pen, reflects individual brain functioning.
Some evolutionary anatomists use the term hand to refer to the appendage of digits on the forelimb more generally — for example, in the context of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand.
The hand has 27 bones, 14 of which are the phalanges (proximal, medial, and distal) of the fingers. The metacarpal is the bone that connects the fingers and the wrist. Each human hand has 5 metacarpals.
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