Written by: Alisha Thakur (11th grade / Ashburn, VA USA) Editor: Noelle A. Koo (11th grade / Ashburn, VA USA)
Research Question/Problem:
This research raises the question about how birds, whales, and other animals that migrate know how to take the route that they do, even if they haven’t done it before. It is thought that they use observations such as the sun’s position, knowledge of the celestial map if they travel at night, or that they take note of specific local landmarks. However, another theory that has been generally accepted for many decades now is that they are able to somehow sense the earth’s magnetic field. However, what is not known is what mechanism specifically the birds use to do that. The research done was purely theoretical. The equations derived in the study have yet to be demonstrated with qualitative evidence.
Protocol/Conclusions:
One of the current leading theories is that the birds can somehow “see” changes in the earth’s magnetic field. The theory involves the photoreceptor protein called cryptochrome, found on the back of the bird’s eye. The proposed system involves “radical-pair processes that are governed by anisotropic hyperfine coupling between (unpaired) electron and nuclear spins.” Radical pairs are two atoms or molecules that have an odd number of electrons. I honestly could not really understand what anisotropic hyperfine coupling is. It has something to do with the relationship between electron spins and the nucleus of the atom. In essence, the theory states that depending on what the direction of the magnetic field is at the bird’s current location, there will be a different reaction with the cryptochrome protein, which will result in specific signals being sent to the bird’s brain, which will affect what the bird sees. The research paper did a lot of math to model the process. However, a lot of assumptions were made simplifying the process for the sake of creating the models. It is not known how much the simplified factors will affect the model.
Interest:
This research combines two very interesting and controversial fields: biology and quantum mechanics. I am really interested in learning about both of these fields, so a combination of the two greatly appealed to me. Also, I think this information is just really cool. It is possible that the birds can actually see the differences in the magnetic field, and they manage to make journeys that span hundreds of miles based on this information and instinct alone. In addition, currently accepted quantum theory only usually works on the subatomic level, and it dissolves, or decoheres, on macroscopic objects, especially in complex, living organisms. If evidence in favor of the hypothesis presented in this paper were to be found, it would open a world of possibilities where quantum physics plays alongside biology. It would also cause the workings of quantum mechanics to be questioned.
References
Ritz, T., Adem, S., & Schulten, K. (2000). A model for photoreceptor-based magnetoreception in birds. Biophysical journal, 78(2), 707–718. doi:10.1016/S0006-3495(00)76629-X
Link for article pdf: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1300674/pdf/10653784.pdf
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