Month: September 2022

FACE CONCEPT. “Vertebrate faces "may be conceptualized as consisting of structurally and functionally integrated units based upon these demands but evolution of these units and the face as a whole are constrained by phylogeny and developmental pathways.” https://lnkd.in/dfD33KM View in LinkedIn

FUNCTIONAL CLUSTER. “The evolution of the vertebrate face provided a location where most of the sensory organs and the innovation of dentition could be clustered, greatly increasing foraging and hunting efficiency relative to invertebrates.” http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full View in LinkedIn

FACE CONNECTED TRAITS. “Mammals evolved features including heterodonty (teeth of different shapes), mammary glands and suckling, an external nose, mobile vibrissae, and mobile external ears, all of which are related to the face.” http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full View in LinkedIn

EVOLUTIONARY SHIFTS. “These evolutionary innovations are associated with a shift away from communication centered primarily on chemical senses toward the greater inclusion of auditory and visual communication modes. Increased reliance on auditory and visual communication was also accompanied by reorganizations within the auditory, visual, and olfactory regions of the brain.” http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full View in LinkedIn

COMMUNICATION. “Although most mammals still use olfaction as a social communication tool (with the probable exception of cetaceans), the production of sometimes elaborate vocalizations/calls, the mammalian cochlea and three-ossicle middle ear, and the development of patterned, brightly colored fur and skin point to the importance of auditory and visual communication among mammals.” http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full View in LinkedIn

ANIMATED MASK. “The advent of mammalian apomorphies related to the face is associated with the most mobile and ornamentally patterned faces among all vertebrates. Mammals have the ability to deform the facial mask (including movement of the vibrissae) and the external ears via contraction of the mimetic muscles.” http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full View in LinkedIn

THE LEVERS. “Mammalian mimetic musculature is unique among other vertebrates in their attachments directly into the soft, mobile dermis of the face, including the cartilages of the external ears and external nose.” http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full View in LinkedIn

MIMETIC MUSCULATURE. “Non-mammalian vertebrates use these muscles in breathing and feeding functions but in mammals they also take on new roles assisting with gathering sensory information, making facial displays or expressions during social interactions, moving the external ears, and changing the size of the openings for the external nose, eyes, and mouth.” http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full View in LinkedIn

FACIAL DISPLAYS. “Primates, especially anthropoids, are dependent upon visual communication more so than most other mammalian orders and this often occurs via facial displays. Indeed, the evolution of trichromatic vision and the high visual acuity within Old World primates have been linked at least in part to their elaborate use of visual communication, including skin and fur pigmentation and facial displays.” http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full View in LinkedIn

SO ENDS this first of two weekends focused on the evolution of the human face. We take faces for granted in daily life, as sources of beauty or communication, but the evolution of this complex anatomy reveals how this muscle mask has been driven by functional needs of the human social animal at a number of levels, from hunting, dentition, breast feeding, and communication. View in LinkedIn