Document Type



Master of Science



Date of Defense


Graduate Advisor

Dr. Aimee Dunlap


Dr. Lon Chubiz

Dr. Zuleyma Tang Martinez


As seen in decades of psychology research, preferences play a major role in driving the decision-making process in both humans and animals. Researchers have advocated for using the technique of experimental evolution as a way to address some of the foundational questions on preferences. These preferences can also affect what is later learned and how well new experiences are learned. Salience is usually mentioned as an important component of what could influence preferences. Animals such as Drosophila melanogaster, that lay eggs without any additional maternal or paternal care, it is important to be selective when deciding where to lay those eggs for their offspring to survive. It has been found that olfactory and gustatory cues play a huge role as an oviposition stimulant and in guiding choice. Using populations of flies with a known evolutionary history (for the previous 200 generations), we are asking questions about how learning and preference interact. We are able to directly test this major assumption in animal learning because we have experimentally evolved populations of flies to have different substrate preferences for where females will lay their eggs; because this evolutionary history is known, and has been directly manipulated, we have an excellent ability to test this assumption. We have evidence of salience of orange as a stimulus that extends beyond the experimental evolution and with this, use a basic paradigm of taste aversion and find that evolutionary history or having an evolved innate bias does affect learning in an overshadowing paradigm.