The phantoms of a high-seven - or - why do our thumbs stick out?

The earliest tetrapods had hands and feet with up to eight digits but this number was subsequently reduced during evolution. It was assumed that lineages with more than five digits no longer exist but investigations of clawed-frogs now indicate that they posses a rudimentary or atavistic sixth digit in their hindlimb. A recent reevaluation of the stem tetrapod Ichthyostega predicts that its seven digits evolved from two different types of ancestral fin radials, pre-axial and post-axial. In this context we now ask the question, should we consider a pre-axial origin of the thumb as reason for its unique genetic signature?

• Publication year

  2015

• Venue

  Frontiers in Zoology

• Publication date

  2015-09-15

• Fields of study

  Biology, Medicine

• Identifiers
  DOI 10.1186/s12983-015-0117-xPMID 26379756PMCID 4570229
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar, PubMed

• No claims are published for this paper.

• No concepts are published for this paper.

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