Anatomy category: From Rui Diogo at Frontiers in Ecology and Evolution:
Just-so stories are prominent in human evolution literature because of our tendency to create simple progressionist narratives about our “special” place in nature, despite the fact that these stories are almost exclusively based on hard tissue data. How can we be so certain about the evolution of human facial communication, bipedalism, tool use, or speech without detailed knowledge of the internal anatomy of for instance, one of the two extant species more closely related to us, the bonobos? Here I show how many of these stories now become obsolete, after such a comprehensive knowledge on the anatomy of bonobos and other primates is finally put together. Each and every muscle that has been long accepted to be “uniquely human” and to provide “crucial singular functional adaptations” for our bipedalism, tool use and/or vocal/facial communication, is actually present as an intra-specific variant or even as normal phenotype in bonobos and/or other apes.
Seven examples, from dissection, are offered.
Therefore, the detailed study of the internal anatomy of our closest relatives, the apes, exposes the fallacy of the simplistic and progressivist narratives that have been accepted for so long—and continue to be—, often as dogmas. Only the strong bias toward a vision of humans as so special and specialized, associated with a clearly outdated extreme adaptationist framework (see Diogo, 2017), can explain how those ideas became to be so easily accepted, without being tested against actual empirical data about the internal anatomy of other primates. More.
Paper. Rui Diogo, First Detailed Anatomical Study of Bonobos Reveals Intra-Specific Variations and Exposes Just-So Stories of Human Evolution, Bipedalism, and Tool Use, Front. Ecol. Evol., 26 April 2018 | https://doi.org/10.3389/fevo.2018.00053
The researchers do not, given the specific scope of their project, address the question of why those features made so much more difference to humans. The explanatory chasm persists.
See also: Are apes entering the Stone Age?
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The Science Fictions series at your fingertips: Human evolution