They can maybe find a cure to help people live longer.
Biology or Geology. These answers make the most sense to me.
Genetics has an important part to play if Mark has a chance of becoming an Olympic swimmer. It would be beneficial if he inherited traits from his grandfather that are essential to develop into a good swimmer. These traits include large hands and feet, wide shoulders, slim hips and a high arm span to height ratio. With these traits and dedicated training Mark would have a chance of making it to the Olympics.<span />
