Honors Theses
Date of Award
5-8-2026
Document Type
Undergraduate Thesis
Department
Biology
First Advisor
Peter C. Zee
Second Advisor
Michel E. B. Ohmer
Third Advisor
Mandy King
Relational Format
Dissertation/Thesis
Abstract
Climatic conditions in the near future are projected to be warmer, with more frequent and intense weather events. This will substantially alter the environments in which organisms must integrate specific information to find essential resources. Many organisms rely upon chemical signals to orient towards attractive resources through a mechanism called chemotaxis. How different environmental conditions, like temperature, impact this process will be important to understand as environments change. I conducted a laboratory evolution experiment with the model nematode Caenorhabditis elegans to see how success in chemotaxis assays changes over time when selected under different temperature regimes (normal laboratory temperature, increased ambient temperature, and heat shock conditions) crossed with different food geography treatments (nearby or distant food patches). I also investigated the impact of these selection regimes on spontaneous locomotion in the offspring generation using worm tracking software to identify how the experimental selection design influenced the inheritance of locomotive motifs. I found that the temperature regime in which worms were selected influenced their chemotaxis success, with the worms experiencing heat shock performing worse than control worms. Additionally, my results show that worms did evolve to perform an increased frequency of reversals. My study also reveals that worms experiencing different food geographies will perform different off-food searching behaviors in the offspring generation. This study demonstrated that projected climatic conditions will have negative impacts on organisms that utilize chemotaxis for resource acquisition and evidence that transgenerational inheritance of traits is not always adaptive.
Recommended Citation
Smith, Hailey R., "Evolution of nematode prey chemotaxis behavior across different environments" (2026). Honors Theses. 3506.
https://egrove.olemiss.edu/hon_thesis/3506
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