VIOLATION OF DOLLO'S LAW: EVIDENCE OF MUSCLE REVERSIONS IN PRIMATE PHYLOGENY AND THEIR IMPLICATIONS FOR THE UNDERSTANDING OF THE ONTOGENY, EVOLUTION, AND ANATOMICAL VARIATIONS OF MODERN HUMANS
Article first published online: 5 APR 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 66, Issue 10, pages 3267–3276, October 2012
How to Cite
Diogo, R. and Wood, B. (2012), VIOLATION OF DOLLO'S LAW: EVIDENCE OF MUSCLE REVERSIONS IN PRIMATE PHYLOGENY AND THEIR IMPLICATIONS FOR THE UNDERSTANDING OF THE ONTOGENY, EVOLUTION, AND ANATOMICAL VARIATIONS OF MODERN HUMANS. Evolution, 66: 3267–3276. doi: 10.1111/j.1558-5646.2012.01621.x
- Issue published online: 1 OCT 2012
- Article first published online: 5 APR 2012
- Accepted manuscript online: 13 MAR 2012 11:29AM EST
- Received October 30, 2011 Accepted February 13, 2012
- Dollo's law;
According to Dollo's law, once a complex structure is lost it is unlikely to be reacquired. In this article, we report new data obtained from our myology-based cladistic analyses of primate phylogeny, which provide evidence of anatomical reversions violating Dollo's law: of the 220 character state changes unambiguously optimized in the most parsimonious primate tree, 28 (13%) are evolutionary reversions, and of these 28 reversions six (21%) occurred in the nodes that lead to the origin of modern humans; nine (32%) violate Dollo's law. In some of these nine cases, the structures that were lost in adults of the last common ancestor and are absent in adults of most subgroups of a clade are actually present in early ontogenetic stages of karyotypically normal individuals as well as in later ontogenetic stages of karyotypically abnormal members of those subgroups. Violations of Dollo's law may thus result from the maintenance of ancestral developmental pathways during long periods of trait absence preceding the reacquisition of the trait through paedomorphic events. For instance, the presence of contrahentes and intermetacarpales in adult chimpanzees is likely due to a prolonged/delayed development of the hand musculature, that is, in this case chimpanzees are more neotenic than modern humans.