Quantcast
ZME Science
  • News
  • Environment
  • Health
  • Future
  • Space
  • Features
    • Natural Sciences
    • Physics
      • Matter and Energy
      • Quantum Mechanics
      • Thermodynamics
    • Chemistry
      • Periodic Table
      • Applied Chemistry
      • Materials
      • Physical Chemistry
    • Biology
      • Anatomy
      • Biochemistry
      • Ecology
      • Genetics
      • Microbiology
      • Plants and Fungi
    • Geology and Paleontology
      • Planet Earth
      • Earth Dynamics
      • Rocks and Minerals
      • Volcanoes
      • Dinosaurs
      • Fossils
    • Animals
      • Mammals
      • Birds
      • Fish
      • Amphibians
      • Reptiles
      • Invertebrates
      • Pets
      • Conservation
      • Animal facts
    • Climate and Weather
      • Climate change
      • Weather and atmosphere
    • Health
      • Drugs
      • Diseases and Conditions
      • Human Body
      • Mind and Brain
      • Food and Nutrition
      • Wellness
    • History and Humanities
      • Anthropology
      • Archaeology
      • History
      • Economics
      • People
      • Sociology
    • Space & Astronomy
      • The Solar System
      • Sun
      • The Moon
      • Planets
      • Asteroids, meteors & comets
      • Astronomy
      • Astrophysics
      • Cosmology
      • Exoplanets & Alien Life
      • Spaceflight and Exploration
    • Technology
      • Computer Science & IT
      • Engineering
      • Inventions
      • Sustainability
      • Renewable Energy
      • Green Living
    • Culture
      • Culture & Society
      • Bizarre Stories
      • Lifestyle
      • Art and Music
      • Gaming
      • Books
      • Movies and Shows
    • Resources
      • How To
      • Science Careers
      • Metascience
      • Fringe Science
      • Science Experiments
      • School and Study
  • Reviews
  • More
    • Agriculture
    • Anthropology
    • Biology
    • Chemistry
    • Electronics
    • Geology
    • History
    • Mathematics
    • Nanotechnology
    • Economics
    • Paleontology
    • Physics
    • Psychology
    • Robotics
  • About Us
    • About
    • The Team
    • Advertise
    • Contribute
    • Privacy Policy
    • Contact
No Result
View All Result
ZME Science

No Result
View All Result
ZME Science

Home → Science → Anthropology

Which came first: the dexterous hand or the agile foot?

Tibi Puiu by Tibi Puiu
October 7, 2013
in Anthropology, Neurology, Research, Science

Shape of the hand and foot in two primate species. The fingers are represented independently (colour coded) in the primate somatosensory cortex (SI). By contrast, the representations of the toes are fused, with the exception of the big toe in humans. (Credit: Image courtesy of RIKEN)
Shape of the hand and foot in two primate species. The fingers are represented independently (colour coded) in the primate somatosensory cortex (SI). By contrast, the representations of the toes are fused, with the exception of the big toe in humans. (Credit: Image courtesy of RIKEN)

A common assumption in human evolution is that our early ancestors first developed bipedal locomotion and only then did they developed dexterous hands capable of using tools, since these were free to be used no longer being required for walking. A new research by a team of Japanese scientists proved this long-standing assumption wrong, however, after they used high-end laboratory techniques to show that dexterous hands evolved before agile feet used in locomotion.

The research is particularly interesting because it combines a range of multi-disciplinary techniques and makes use of evolutionary correlations between modern humans and monkeys of today and those from the dawn of our genus. The researchers led by neurobiologist Dr. Atsushi Iriki of the RIKEN Brain Science Institute employed functional magnetic resonance imaging in humans and electrical recording from monkeys to locate the brain areas responsible for touch awareness in individual fingers and toes, called somatotopic maps. These maps showed that both humans and monkeys have discrete neural signatures for single digits in the hand and foot.

[READ MORE] Why human ancestors started walking on two legs

There's one prominent difference between the monkey and human maps: the human big toe has its own map, while all monkey toes are combined and fused into one single map. These findings suggest that early hominids evolved dexterous fingers when they were still quadrupeds. Manual dexterity was not further expanded in monkeys, but humans gained fine finger control and a big toe to aid bipedal locomotion.

"In early quadruped hominids, finger control and tool use were feasible, while an independent adaptation involving the use of the big toe for functions like balance and walking occurred with bipedality," the authors explained.

To support these laboratory findings, the researchers showcased the well-preserved hand and feet bones of a 4.4 million year-old skeleton of the quadruped hominid Ardipithecus ramidus, a species with hand dexterity that preceded the human-monkey lineage split. In all, the findings suggest that our early ancestors first developed hand dexterity, critical to tool use, while two-legged locomotion came after as a consequence of adaptive pressures on ancestral quadrupeds for balance control by foot digits.

"Evolution is not usually thought of as being accessible to study in the laboratory," stated Dr. Iriki, "but our new method of using comparative brain physiology to decipher ancestral traces of adaptation may allow us to re-examine Darwin's theories."

The results were reported in a paper published in journal Philosophical Transactions of the Royal Society.

Was this helpful?


Thanks for your feedback!

Related posts:
  1. Man’s hand is grafted onto his foot for transplant
  2. Working a desk job could keep your mind agile later on in life
  3. Fossil Friday: footprints point to surprisingly-agile meat-eating dinosaurs
  4. Ants surprisingly agile even in microgravity, ISS experiment shows
  5. Conspiracy theories and anti-vaccine sentiments go hand-in-hand
Tags: homo sapienshuman ancestorsmonkeysprimatessomatotopic map

ADVERTISEMENT
  • News
  • Environment
  • Health
  • Future
  • Space
  • Features
  • Reviews
  • More
  • About Us

© 2007-2021 ZME Science - Not exactly rocket science. All Rights Reserved.

No Result
View All Result
  • News
  • Environment
  • Health
  • Future
  • Space
  • Features
    • Natural Sciences
    • Physics
      • Matter and Energy
      • Quantum Mechanics
      • Thermodynamics
    • Chemistry
      • Periodic Table
      • Applied Chemistry
      • Materials
      • Physical Chemistry
    • Biology
      • Anatomy
      • Biochemistry
      • Ecology
      • Genetics
      • Microbiology
      • Plants and Fungi
    • Geology and Paleontology
      • Planet Earth
      • Earth Dynamics
      • Rocks and Minerals
      • Volcanoes
      • Dinosaurs
      • Fossils
    • Animals
      • Mammals
      • Birds
      • Fish
      • Amphibians
      • Reptiles
      • Invertebrates
      • Pets
      • Conservation
      • Animal facts
    • Climate and Weather
      • Climate change
      • Weather and atmosphere
    • Health
      • Drugs
      • Diseases and Conditions
      • Human Body
      • Mind and Brain
      • Food and Nutrition
      • Wellness
    • History and Humanities
      • Anthropology
      • Archaeology
      • History
      • Economics
      • People
      • Sociology
    • Space & Astronomy
      • The Solar System
      • Sun
      • The Moon
      • Planets
      • Asteroids, meteors & comets
      • Astronomy
      • Astrophysics
      • Cosmology
      • Exoplanets & Alien Life
      • Spaceflight and Exploration
    • Technology
      • Computer Science & IT
      • Engineering
      • Inventions
      • Sustainability
      • Renewable Energy
      • Green Living
    • Culture
      • Culture & Society
      • Bizarre Stories
      • Lifestyle
      • Art and Music
      • Gaming
      • Books
      • Movies and Shows
    • Resources
      • How To
      • Science Careers
      • Metascience
      • Fringe Science
      • Science Experiments
      • School and Study
  • Reviews
  • More
    • Agriculture
    • Anthropology
    • Biology
    • Chemistry
    • Electronics
    • Geology
    • History
    • Mathematics
    • Nanotechnology
    • Economics
    • Paleontology
    • Physics
    • Psychology
    • Robotics
  • About Us
    • About
    • The Team
    • Advertise
    • Contribute
    • Privacy Policy
    • Contact

© 2007-2021 ZME Science - Not exactly rocket science. All Rights Reserved.

Don't you want to get smarter every day?

YES, sign me up!

Over 35,000 subscribers can't be wrong. Don't worry, we never spam. By signing up you agree to our privacy policy.

✕
ZME Science News

FREE
VIEW