Coconuts are the fruit of the cocoa palm, Cocos nucifera. The coconut that we buy is the “kernel” of the fruit – the coconut that falls from the tree is much larger than this because it consists of the “kernel” surrounded by a thick fibrous layer inside a waterproof outer case.
These seeds have evolved to be spread by water although now they are usually spread by people. A coconut can move up to 10m from its parent tree just by bouncing and rolling after falling to the ground from a height of 10 to 20m. Coconuts can also survive up to 120 days afloat in the sea and then germinate when they are washed up on land. After germination the milky water inside the seed will provide enough moisture to sustain the seedling, even in sandy conditions.
In this experiment students investigating the physics of floating and falling coconuts, using the coconut “kernel”. This makes an excellent idea for looking at evolution and adaptation in an unusual context.
This activity combines physics, biology and maths, and makes a great school STEM club or science club activity.
This resource was developed by Lynn Nickerson of Didcot Girls School, a science technician and SAPS Associate, and was funded by a SAPS Associate Award