72583
Another explanation is provided by the genetic kinship theory of William D. Hamilton : if a gene causes an individual to help other individuals that carry copies of that gene , then the " gene " has a net benefit even with the sacrifice of a few individuals .
 William D. Hamilton
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:
 William D. Hamilton