The evolution of a novel mating signal

Contributed by: Robin Tinghitella @robinmting

 

Keywords

Animals, Behavior, Behavioral Ecology, Communication, Ecology, Evolution, Field, Fundamental research, Genetics, Geographical location, Host-Parasite, Interactions, Lab, Mendelian genetics, Mother, Natural selection, Observational, Oceania, Physiological/organismal ecology, Sexual selection, Speciation, Terrestrial, Woman

 

Slides

Note: click the gear symbol to see notes that accompany the presentation

View and download in google slides here

 

Resources

Robin M. Tinghitella, E. Dale Broder, Gabrielle A. Gurule-Small, Claudia J. Hallagan, and Jacob D. Wilson. 2018. Purring Crickets: The Evolution of a Novel Sexual Signal. The American Naturalist 192(6): 773-782.
link

Data Nugget Activity: http://datanuggets.org/2021/03/purring-crickets-the-evolution-of-a-new-cricket-song/

Notes

Slide 1: Researcher’s Background

Robin is an evolutionary biologist at the University of Denver where she studies the rapid evolution of animal communication.

PB: Why did you become a biologist?
RT: I love discovery and the opportunity to pursue whatever questions and problems interest me at the moment!

PB: What is your favorite part about your job?
RT: My students. Hands down best part of the job. The travel isn’t bad either :)

PB: What obstacles have you overcome to get where you are?
RT: I grew up in a family that greatly valued education, but didn’t have any experience with advanced degrees or academia, and then I went to a small liberal arts college where there were no graduate students, so graduate school and what came after that (postdocs, jobs) was a complete mystery to me. As a woman and mother of three, I’ve also unfortunately encountered a lot of sexism and bias from academics who incorrectly believe that my life choices outside of work are not compatible with my job.

PB: What advice do you have for aspiring biologists?
RT: It’s important to find lots of mentors – not just one. I’ve found that colleagues, friends, and those who are further along in their careers make excellent mentors and you really can’t rely on one teacher or mentor to fill the diversity of roles that you’ll need over the years. 

PB: Do you feel that any dimension of your identity is invisible or under-represented/marginalized in STEM?
RT: Yes

PB: Can you elaborate on your answer above?
RT: At my university, at least, being woman and a mother is unfortunately quite uncommon in the STEM fields. I have definitely felt marginalized because of my life decisions.

 

Slide 2: Research Overview

Take home message of study

We discovered that crickets on the island of Molokai are producing a brand new song that sounds like a purring cat! This is the first time that the evolution of a brand new mating signal has been observed in real time.

Study system

Up close look at a male Pacific field cricket, Teleogryllus oceanicus.

 

Slide 3: Key Research Points

Main figure

This figure describes three different “morphs” (types) of male Pacific field crickets that are found within Hawaii: A. silent cricket that evolved <20 years ago and cannot produce any songs, B. purring crickets that were discovered in 2017 and produce a brand new unique song, and C. the typical ancestral (pre-existing) type of male. For each male type we show the wing structures that produce the songs and visuals of the songs themselves (top = waveform, bottom = spectrogram). The newly evolved purring song is quieter than the typical song (lower amplitude; see waveforms B vs C), has a higher peak frequency (pitch; see spectrograms B vs C), and is more broadband (has power spread across a wider range of frequencies; see spectrograms B vs C).

 

Societal Relevance

Research in evolutionary biology broadly helps us to understand how all of the biodiversity that we observe on a day to day basis is generated and maintained. Rapid evolution, like what we observed in Hawaii, gives us a window into these processes in real time, rather than looking backward at changes that have already occurred. The evolution of new mating signals, in particular, is thought to be important for the generation of new species (speciation).