Cacti Collect Fog

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Cacti collect fog, according to report in Nature Communications, doi: 10.1038/ncomms2253, 4 December 2012. Cacti are well known for efficient methods of storing water, but before they can store water they have to collect it. Lei Jiang of the Institute of Chemistry of the Chinese Academy of Sciences in Beijing and colleagues, have studied how a cactus named Opuntia microdasys is able to harvest water from fog. This plant has clusters of spines made up of fine strap-like filaments set in bases named trichomes.

The scientists examined the spines with an electron microscope and recorded the movement of water droplets along them. They found the tips of the spines were covered with tiny conical barbs that provided a larger surface area for collecting water droplets, and these were orientated in such a way as to force the water to move down grooves in the sides of the spines. The grooves are arranged in a spiral, and become wider and smoother as they get closer to the base. This facilitated the movement of drops to the bases where other drops from adjacent spines coalesced into one large drop on the trichome. The water is then rapidly absorbed by the trichome and stored within the stem.

The research team wrote: “The integration of the multiple functions within the spines and the trichomes, including water deposition, collection, transportation and absorption in the cactus, facilitated an efficient fog collection system”. They also suggested, “The investigation into the structure–function relationship within this system may offer systematic options that can be used to design novel materials and devices to efficiently collect fog”. The scientists then suggested such fog collecting devices could help people to live in arid areas.

Editorial Comment: The usual explanation for cacti spines is that they evolved to deter animals from eating the cactus. However spikes that function as mere animal deterrents do not need such a well designed system for collecting water. The findings of this study remind us that if you ask how would you deliberately design plants for a world watered by a rising mist, such as is described in Genesis 2:5-6, the fog collecting system of these cacti would have been a great solution. What was their subsequent track record to desert type survivors? The Bible does record that after Noah’s flood the climate and the environment rapidly degenerated. Droughts are the key to desert formation, and these begin to get a mention within several centuries after Noah. Cacti, with their ability to extract water from fog, rather than waiting for rain to moisten the soil, survived in such arid places whilst other plants died out.

This is natural selection, but it is not evolution. Natural selection eliminates living things, but it is not a process that produces new life or new structures, such as the cactus water collecting system. It removes living things that can no longer survive in a tough environment, e.g. plants without fog collecting systems, and such a process has become a dominant eliminator only since the flood. It was not part of God’s original very good creation.

We are also pleased to see researchers admit it will take brainy design to make fog collecting devices to help people living in arid areas. Oops … that means they have no excuse for rejecting God’s original smart design to make cactus fog collecting devices. (Ref. succulents, biomimicry, water cycle)

Evidence News 24 July 2013

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