Nearly two centuries ago a young biologist on a ship 60 miles from the nearest coastline was amazed by some spiders. The spiders were showing up on his ship when they had not been there before. Since his discovery, other researchers have seen similar mysterious migrations of ballooning spiders across open waters. Scientists have studied this amazing technique on Robinson Crusoe Island in the Pacific Ocean 415 miles off the coast of Chile.
The spiders climb to a high point and secure themselves with silk. The spiders have fine hairs called trichobothria which they use to sense wind direction and electric conditions. When it rains, electrons are carried to the ground making the ground negatively charged and the upper atmosphere positively charged. The spiders sense the field that results from this separation of charge. When conditions are right, the spiders release a silk that is so light that even the slightest breeze will keep it afloat. As the spiders spin off this low-density silk, their spinnerets also acquire a negative charge from the ground. The negative charge of the ground repels the negative charge on the silk. When the electric field and the breeze are strong enough, the spiders release the securing silk and become lifted into the air.
The ballooning spiders can rise up to 2.8 miles high and ride the winds for thousands of miles needing no food or water. When they land, they attach themselves and deposit their eggs. The ones that land on Robinson Crusoe Island are called ghost spiders.
The question of why this system is built into the spider’s DNA, how it knows when to send out different kinds of silk, and how it knows to use its legs for flight control is still being studied. There is no connection to other spiders and no compelling force to make them leave their original habitat.
We suggest that God has built incredible designs into all living things that allow the whole world to be populated and repopulated when climate change or other natural processes cause local extinction. By the way, the young biologist who first noticed the ballooning spiders technique was Charles Darwin.
— John N. Clayton © 2019