ABSTRACT

Just as humans use voices to talk to one another, many other animals also use sound for communication. The use of sound to send and receive messages, known as acoustic communication, is found in many different types of animals, including insects, birds, frogs, and mammals. Among these animals, singing insects, such as crickets and katydids, were the first to evolve the ability to hear and produce sound an estimated 300 million years ago. Since then, crickets, katydids, and relatives (Ensifera) have diversified extensively, giving rise to an estimated 15,000 known species, and several different mechanisms of hearing and singing. They now represent the most diverse group of organisms that rely on acoustic communication. Therefore, studying how hearing and singing evolved and diversified in these insects can reveal important insights about the origin and evolution of animal communication. This collaborative research project including scientists from the United States, the United Kingdom, and France will gather a massive amount of genetic data to reconstruct evolutionary relationships among crickets, katydids, and relatives. The team will also employ cutting-edge techniques in three-dimensional imaging, biophysics, and genomics to investigate the diverse mechanisms of hearing and singing in these insects. This project will fill important gaps in understanding the biodiversity and bioacoustics of the group and provide unique educational opportunities including, project-enabled outreach activities targeting K-12 students, hands-on undergraduate research experience to six Polynesian and Hispanic undergraduate students, as well as training of two graduate students and two postdoctoral researchers.

This project will produce a comprehensive dated phylogeny of Ensifera (crickets, katydids, and relatives), the most speciose and ancient lineage of the extant singing insects, based on 1,600 species and 1,000 loci generated from target capture DNA sequencing. Using this phylogeny as a robust comparative framework, the researchers will generate an unprecedented amount of detailed morphological, biophysical, and genetic data using X-ray micro- and nano- computed tomography (CT) scanning, micro-scanning laser Doppler vibrometry, and RNA-seq across major ensiferan lineages to identify mechanisms of hearing and singing. Researchers will measure real-time ear function and compare 3-dimensional anatomy and biophysical properties of hearing organs, conduct a large-scale comparative analysis of sound-producing organs and their corresponding song frequencies using both extinct and extant species, and generate and compare wing venation genes and tibial hearing organ transcriptomes. Using these data, researchers will address several longstanding questions about when acoustic communication first evolved and how often it has been lost, how lineages independently evolved different hearing and signaling mechanisms, what the physical, neural and genetic bases of these hearing and signaling mechanisms are, and how signaling diversity is linked to diversification and speciation. These findings will collectively reveal general insights about the evolution of acoustic communication that could serve as a model for the study of similar mechanisms in other insects.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Please report errors in award information by writing to: awardsearch@nsf.gov.