Mosaic evolution. An example in the origin of Neandertals

The emergence of Neandertal morphology (Homo neanderthalensis) is associated with the appearance of mosaic phenotypes in Middle Pleistocene ancestral populations. Using this case as a reference, we analyze the concept of “mosaic evolution”. Mosaic evolution suggests that different traits can evolve...

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Detalles Bibliográficos
Autores: Rosas, Antonio, Bastir, Markus, García-Tabernero, Antonio, Alarcón, José Antonio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/388995
Acceso en línea:http://hdl.handle.net/10261/388995
Access Level:acceso abierto
Palabra clave:Human evolution
Morphological integration
Middle Pleistocene
Hominin
Neandertal
Descripción
Sumario:The emergence of Neandertal morphology (Homo neanderthalensis) is associated with the appearance of mosaic phenotypes in Middle Pleistocene ancestral populations. Using this case as a reference, we analyze the concept of “mosaic evolution”. Mosaic evolution suggests that different traits can evolve independently, at different times, resulting in various combinations of primitive and derived traits (mosaics) in descendant species. Often, the seemingly random nature of these trait combinations is interpreted within the conceptual framework of population genetics, where the different states of anatomical traits are seen as direct expressions of allelic variants. In this paper, we propose that the appearance of these mosaics of traits in Middle Pleistocene hominins of Europe occurred within a complex network of morphogenetic interactions involving two factors that affect the organism as a whole. First, during the early part of the Middle Pleistocene, there is an increase in body size, and consequently, an increase in metabolism, which may have affected facial anatomy through the expansion of the respiratory tract. Second, the hominin lineage from which Neandertals, Denisovans, and modern humans descend experiences an increase in the size of certain brain areas, leading to changes in the anatomy of the cranial vault and the integration of anatomical systems related to the base of the skull. In this context, changes in the overall orientation of the basicranium and in the topological relationships between the midline of the skull base and the lateral portions of the skull (temporal fossae) can be explained from an organismic perspective.