The study is the largest ever investigation of the evolution of the larynx between species.
Scientists have found that the larynx, or voice box, of primates significantly larger than their body size, has a greater variation and has a faster rate of evolution. other mammals.
Posted in the magazine PLOS Biology and led by scholars from Anglia Ruskin University (ARU), Stanford University and University of Vienna, this study is the first large-scale study on the evolution of the larynx.
The larynx has three main functions: protecting the airways during sucking, regulating the supply of air to the lungs, and communicating by voice. Due to its important role in facilitating social behavior, through voice it has long been believed that the larynx is an important area of evolution, especially in species. has a highly developed voice communication system.
The researchers CT scans samples from 55 different species and created 3D computer models of their larynx. They are studied along with detailed measurements, including body length and body mass.
Primate species vary in size, from dwarf gorillas (Cebuella pygmaea) weighing just 110g, to Western gorillas (Gorilla gorilla) weighing around 120kg. The carnivores range from a common dwarf mongoose weighing 280g (Helogale parvula) to a tiger weighing 180kg (Panthera tigris).
Research shows that, with a certain length of body, primate larynx is on average 38% larger than the larynx of predators and the laryngeal evolution rate in these species is faster.
Laryngeal size also varies more than body size among primates, suggesting that primates have a greater flexibility to evolve in different ways. Predators obey a more fixed laryngeal-to-body size ratio.
Laryngeal size is also considered to be a good predictor of a species’ calling frequency, which demonstrates the involvement of voice communication of observed size variations.
Co-author Dr Jacob Dunn, Reader on Evolutionary Biology at Anglia Ruskin University (ARU), said: “This study demonstrates a clear difference in laryngeal evolution between groups. mammal.
“Specifically, we have demonstrated for the first time that the primate’s larynx is larger, less closely linked to body size and has a faster evolution rate than the carnivore’s larynx. is a suitable comparison group, showing fundamental differences in the evolution of the phonetic organ between species. “
Lead co-author, Dr. Daniel Bowling, Lecturer in Psychiatric and Behavioral Science at Stanford University, added: “Our study also showed that laryngeal size differences predict changes. on the pitch of the voice, highlighting the important role of the larynx in voice communication. This is reflected in the rich and varied calls made by many primates.
“The results show a fundamental difference between primates and predators in the force of laryngeal size restriction, as well as highlight evolutionary flexibility in possible primates. helps explain why they develop complex and varied uses of the vocal organ to communicate. This offers an interesting pathway for future studies examining differences between other mammal groups. “