78051
Tyler Volk , has also looked at the trophic cycling of various elements upon which life depends , and argues that this is central to an understanding of geophysiology .
 Tyler Volk
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Tyler Volk