Apical Phalangeal Tufts

Certainty Style Key
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True   Likely   Speculative
Human Uniqueness Compared to "Great Apes": 
Absolute Difference
MOCA Topic Authors: 

The distal ends of the distal phalanges of the human hand and foot possess flat, mediolateral expansions of bone known as apical tufts. The tufts support the fleshy volar pad (also known as the distal pulp) on the palmar (volar) surface of the finger, as well as the nail on the dorsal surface. Primate species vary in the size of their apical tufts, although none exhibit an expansion as great as that seen in humans. In general, primates engaged in suspensory locomotion tend to have smaller apical tufts, while quadrupedal primates tend to have larger tufts. Enlargement of the human apical tuft may reflect expansion of the digital pulp to enhance friction between the tips of the fingers and held objects (such as hammerstones and lithic cores) in the context of tool manufacture and use.

Related MOCA Topics
Timing

Timing of appearance of the difference in the Hominin Lineage as a defined date or a lineage separation event. The point in time associated with lineage separation events may change in the future as the scientific community agrees upon better time estimates. Lineage separation events are currently defined as:

  • the Last Common Ancestor (LCA) of humans and old world monkeys was 25000 thousand (25 million) years ago
  • the Last Common Ancestor (LCA) of humans and chimpanzees was 6000 thousand (6 million) years ago
  • the emergence of Homo ergaster was 2000 thousand (2 million) years ago
  • the Last Common Ancestor (LCA) of humans and neanderthals was 400 thousand years ago
  • the common ancestor of modern humans was 100 thousand years ago

Possible Appearance: 
2000 Thousand Years
Probable Appearance: 
2000 Thousand Years
Definite Appearance: 
2000 Thousand Years
Background Information: 

Tocheri et al., 2008. The evolutionary history of the hominin hand since the last common ancestor of Pan and Homo. J Anat 212: 544-562.