The Island of the Colorblind and the Cycad Island

The Island of the Colorblind and the Cycad Island by Oliver Sacks

Rare genetic traits may become prominent in isolated populations with significant intermarriage. Deafness became common in Martha's Vineyard thanks to two founders that had a recessive gene. In Micronesia, there is an island (Pingelap) many people are achronotopes. This trait occurred due to a population bottleneck. Colorblindness can be a nerve or a an eye issue. In Micronesia, the colorblind have difficulty seeing during the day, but actually have a better ability to see at night. The book also explores cycads. These seeds are fairly poisonous. However, are consumed after processing to remove the poison. Could this result in some neurological problems? The book covers some interesting topics, but it wanders a bit, with parts travel, genetic and neurological.