Human-like hand use in Australopithecus africanus

  title={Human-like hand use in Australopithecus africanus},
  author={Matthew M. Skinner and Nicholas B. Stephens and Zewdi J Tsegai and Alexandra C. Foote and N. Huynh Nguyen and Thomas Gross and Dieter H. Pahr and Jean‐Jacques Hublin and Tracy L. Kivell},
  pages={395 - 399}
Getting a grip The evolution of the hand—particularly the opposable thumb—was key to the success of early humans. Without a precise grip, involving forceful opposition of thumb with fingers, tool technology could not have emerged. Skinner et al. analyzed the internal bone structure of Pliocene Australopithecus hands, dated at 3.2 million years old. Internal bone structure reveals the patterns and directions of forces operating on the hand, providing clues to the kinds of activities performed… 

Manual Loading Distribution During Carrying Behaviors: Implications for the Evolution of the Hominin Hand

Analysis of recruitment of the distal phalanges during a range of manual transportation events related to hominin behavioral repertoires during the Plio-Pleistocene suggests that the manual transportation of objects may plausibly have influenced the evolution of the human gripping capabilities and the 3rd metacarpal styloid process.

Hand pressures during arboreal locomotion in captive bonobos (Pan paniscus)

Bonobo digit pressures are significantly greater during arboreal knuckle-walking than during either vertical or suspensory locomotion, and the thumb experiences low or no pressure during all locomotor modes.

Evolution of the Early Hominin Hand

The functional significance and evolutionary history of seven major anatomical changes that make the authors' hands distinctive are explored, including hand proportions, thumb robusticity, thumb musculature, distal tuberosities, carpal architecture, wrist mobility, and finger curvature, and a new term, hyper-opposable, is proposed.

Sequence Analysis of Grip and Manipulation During Tool Using Tasks: a New Method to Analyze Hand Use Strategies and Examine Human Specificities

The method is efficient and is the only available method to describe and quantify with such detailed level grip and manipulation as dynamic process in both human and non-human primates without high technical constraint.

Insights into the musculature of the bonobo hand

The functional anatomy of the bonobo hand is investigated using a unique sample of eight bonobo cadavers, along with one chimpanzee and one human (Homo sapiens) cadaver, showing that the force‐generating capacity for most functional groups of the extrinsic and intrinsic hand muscles in bonobos is largely similar to that of humans.

Metacarpal torsion in apes, humans, and early Australopithecus: implications for manipulatory abilities

This paper explores variation in metacarpal torsion, a trait said to enhance manipulation, in humans, apes, early australopithecines and specimens from Swartkrans and supports the hypothesis that dexterous hands largely predated Homo.

The evolution of human and ape hand proportions

High levels of hand disparity among modern hominoids are revealed, which are explained by different evolutionary processes: autapomorphic evolution in hylobatids (extreme digital and thumb elongation), convergent adaptation between chimpanzees and orangutans (digital elongation) and comparatively little change in gorillas and hominins.

The unexpected importance of the fifth digit during stone tool production

The recruitment frequency, loading magnitude, and loading distribution of all digits on the non-dominant hand of skilled flintknappers during four technologically distinct types of Lower Palaeolithic stone tool production are examined.



Precision grips, hand morphology, and tools.

  • M. Marzke
  • Biology
    American journal of physical anthropology
  • 1997
No single skeletal feature can be safely relied upon as an indicator of distinctively human capabilities for precision gripping or tool making in fossil hominids.

Australopithecus sediba Hand Demonstrates Mosaic Evolution of Locomotor and Manipulative Abilities

The hand of Australopithecus sediba, a rare example in the hominid fossil record, shows short fingers and a long thumb consistent with improved precision gripping while retaining strength for climbing, suggesting at least two distinct hand morphotypes around the Plio-Pleistocene transition.

Early Origin for Human-Like Precision Grasping: A Comparative Study of Pollical Distal Phalanges in Fossil Hominins

The results reinforce previous hypotheses relating the origin of refined manipulation of natural objects--not stone tool-making--with the relaxation of locomotor selection pressures on the forelimbs and suggest that human hand length proportions are largely plesiomorphic, in the sense that they more closely resemble the relatively short-handed Miocene apes than the elongated hand pattern of extant hominoids.

Evolution of the power ("squeeze") grip and its morphological correlates in hominids.

Results of the study indicate that humans use a squeeze form of power grip effectively to wield cylindrical tools forcefully as extensions of the forearm.

Chimpanzee and human grips: A new classification with a focus on evolutionary morphology

A new classification of grips is generated, which takes into account three elements of precision and power gripping that appear to distinguish between the chimpanzees and humans, and which have not been explored previously in relation to hand morphology.

Mechanical advantages of the Neanderthal thumb in flexion: a test of an hypothesis.

It was determined that, despite some minor differences in articular dimensions between Neanderthals and recent humans, these pollical phalangeal length contrasts translated into significant differences in mechanical advantages for the flexor muscles across the MCP and IP articulations.

Chimpanzee thumb muscle cross sections, moment arms and potential torques, and comparisons with humans.

Chimpanzee and humans differ in the direction of secondary thumb metacarpal movements elicited by contraction of some muscles, as shown by differences in moment arm signs for a given movement in the same muscle.