Mammalian vocal communication as a model for human speech and language

Context Language is at the core of what makes us human, underpinning our unbounded capacity to exchange thoughts, ideas, and culture. Speech and language rely on complex biological mechanisms shaped by evolution. Studying the biology and evolution of the capacity for language poses unique challenges. Invasive experimentation in humans is unethical, and the lack of fossil evidence for language limits evolutionary insights. For these reasons, despite its importance, the biological basis and evolutionary origins of speech and language remain poorly understood. While no other animal has a full language system, some animals display ‘language-relevant traits’. A key language-relevant trait is vocal learning - the ability to imitate and modify sounds. A comparative approach, exploring vocal learning in animal systems, provides invaluable opportunities to gain insights into biology and evolution of language. However, few tractable animal models for language-relevant traits exist, and those that have dominated the field are either evolutionarily distant from humans, such as birds, or are impractical for experimentation, like whales and seals. This highlights the need for a tractable mammalian model to investigate the genetic and neurobiological foundations of vocal learning. Addressing The Challenge Bats offer an unparalleled opportunity to address these challenges. Bats are small, social mammals that demonstrate robust vocal learning abilities. They are experimentally tractable and can be bred and housed in laboratory facilities. Bats also provide a much closer evolutionary comparison than the dominant model species, birds, which are separated from humans by over 300 million years of evolution. Despite their potential, prior research into bat vocal learning, particularly regarding the genetic and neurobiological mechanisms involved has been limited. Aims and Objectives This project consolidates bats, specifically the pale spear-nosed bat (Phyllostomus discolor), as a groundbreaking mammalian model for vocal learning. The primary aims are to investigate the molecular and neural encoding of vocal learning, and to provide insights into the evolutionary pathways that enable this trait. Key objectives include: Developing genomic and molecular tools in bats. Identifying genes and neural pathways associated with vocal learning. Establishing causative links between genes, brains, and vocal behaviour using transgenic bats. Expanding research on bats to explore new applications and build interdisciplinary networks to exploit this emerging model. Potential Applications and Benefits This research seeks to unravel fundamental biological principles underlying vocal learning, shedding light on how complex behaviours like speech evolved and are encoded in mammals. By comparing bats to other vocal learners, the project aims to uncover convergent and divergent evolutionary mechanisms, offering a deeper understanding of vocal learning across species. This work will also reveal how specific molecular and neural systems interact to enable complex vocal behaviours. The findings may have far-reaching implications for understanding how communication systems evolve and function, providing a broader context for studying the origins of human speech and language. These findings may also provide insight into human language-related disorders which affect >11% of the population. This research provides a unique opportunity to investigate a currently understudied area that represents a major and urgent scientific challenge. By solidifying bats as a key model system, this project opens new avenues for research into neurogenetics, behaviour, and evolution. The integration of diverse disciplines positions bats at the forefront of vocal learning studies and contributes to our understanding of this rare and complex trait.