On page 60, Moalem discusses lactose intolerance. He says,
“the great majority of the world’s adults cannot eat or drink milk without
experiencing a very unpleasant digestive reaction.” I thought this condition was
really interesting because I can’t really imagine not being able to eat ice
cream or drink coffee. I also didn't really know that so many adults are
lactose intolerant. Both my parents can digest lactose, and with further
research into my family’s history, I did find out that some of my ancestors
were once farmers. Are you or any adult in your family lactose intolerant? Were
your ancestors once farmers? This topic of lactose intolerance relates to Big
Idea #1. (The process of evolution drives the diversity and unity of life) My
ancestors evolved to produce the Lactase enzyme as adults, and it helped them
survive and reproduce.
Look into
your family history and try to find some reoccurring occupations of your
ancestors; were they teachers, blacksmiths, bakers, or artists? Relate their
occupation with a mutation you or your family members have. Explain
specifically how this condition may have been favorable for your ancestors’
occupations. Also, explain how this mutation works from a biological
perspective.
(Ilakkiya Thanigaivelan, ithanig3@students.d125.org)
This comment has been removed by the author.
ReplyDeleteMy family, before the last two generations was also predominantly farmers. Therefore, me and most of my family is also lactose tolerant. On page 60 Dr. Moalem says that the majority of adults are lactose intolerant. Lactose in tolerance very predominant in farming families like yours and mine. Scientists don't yet know how exactly people switched from lactose intolerance to lactose tolerance, but they know it started in north eastern Europe. (http://tinyurl.com/cczm8rw)
ReplyDeleteThis mutation works from a biological perspective because farmers obviously lived on farms, so they seldom didn't have cows around. They needed bulls to plow their land. Farmers then used cows to drink their milk. Since the only way people didn't get nauseous or gassy was when they had the mutation, the mutation was selected for on the farms. The farmers could now utilize their farms to a fuller extent.
This mutation works from a biological perspective because people wouldn't get sick as often from having lactose. They also get the calcium and protein from the milk, which greatly reduces mortality. People could survive and reproduce (Big Idea #1).