Night and Day: Genetic and Behavioural Mechanisms of visual and Diel-niche Evolution in Lepidoptera

Authors

Yash Sondhi, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Biology

First Advisor's Name

Jamie Theobald

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Akito Kawahara

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Heather Bracken-Grissom

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Robert Lickliter

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Jeffrey Wells

Fifth Advisor's Committee Title

Committee member

Keywords

automated monitoring, diel-niche, gene evolution, gene expression, insects, light environment, Lepidoptera, moths, transcription factors, visual genes

Date of Defense

8-26-2022

Abstract

Standing outside and watching the sun set, you may not realize that light levels drop more than ten times in just ten minutes. A moonlit night is around a million times darker than a sunny afternoon. In the dark, it is harder to discriminate color, contrast, or fast motion, but most animals must deal with dramatically changing light conditions. Animals can be nocturnal (night), crepuscular (dusk or dawn), or diurnal (day), often referred to as ”diel- niche”. No group better embodies these light extremes than butterflies and moths. They are close relatives, famously active in profoundly different light conditions and have more than a hundred recorded diel-niche switches. Relatively more is known about their natural history and evolutionary relationships than any other insect order, yet our understanding of their visual system is limited to a few species. In my dissertation, I explore how light environment has shaped the evolution of visual genes, behaviour and the diel-niche across butterflies and moths.

In my first chapter, I summarise our current understanding of visual system and diel- niche evolution in Lepidoptera. I provide the background and context for the work along with an overview of the integrative approach I take.

In my second chapter, I examine the distribution and evolution of color vision across the butterfly and moth phylogenetic tree and compare these patterns across day and night flying species. I find that color vision genes have evolved faster and duplicated more often in species active in bright light and many amino acid sites under higher selection are at functional domains in the proteins encoded by these genes.

In my third chapter, I design and test a new behavioural method to quantify fine-scale diel-niche. I use this device to quantify diel-niche of species in the field and to test the effects of light pollution on activity periods.

In my fourth chapter, I explore temporal gene expression patterns across pairs of closely related diurnal and nocturnal species and identify genes showing divergent expression patterns as putative candidate genes driving diel-niche evolution.

In my final chapter, I provide a synthesis of my findings and highlight how my results together improve our understanding of the genetic and behavioural mechanisms underlying vision and diel-niche evolution.

Identifier

FIDC010872

ORCID

0000-0002-7704-3944

Previously Published In

Sondhi, Y., Ellis, E. A., Bybee, S. M., Theobald, J. C., & Kawahara, A. Y. (2021). Light environment drives evolution of color vision genes in butterflies and moths. Communications biology, 4(1), 1-11

Sondhi, Y., Jo, N. J., Alpizar, B., Markee, A., Dansby, H. E., Currea, J. P., ... & Theobald, J. C. (2022). Portable locomotion activity monitor (pLAM): A cost‐effective setup for robust activity tracking in small animals. Methods in Ecology and Evolution, 13(4), 805-812.

Creative Commons License

This work is licensed under a Creative Commons Attribution-Noncommercial 3.0 License

Recommended Citation

Sondhi, Yash, "Night and Day: Genetic and Behavioural Mechanisms of visual and Diel-niche Evolution in Lepidoptera" (2022). FIU Electronic Theses and Dissertations. 5206.
https://digitalcommons.fiu.edu/etd/5206