Hairy Cactus

A South American cactus named Espostoa frutescens is pollinated by bats.  As bats are active at night, how do bats find flowers in dark?  Some bat-pollinated flowers are able to reflect bats’ echolocating sounds, so scientists at Nuremberg Zoo, Germany and Vrije Universiteit, The Netherlands, studied these cacti to see if they had any special acoustic properties. 

They found the main stems of the cacti reflected sound well, the flowers reflected sound moderately well, but the area around the flowers, which is covered with fine hairs, absorbed sound at the frequency of the bat’s sonar calls, around 90 kHz.  The research team suggested the absorbent hairy areas provided an area of contrast enhancement around the flowers to help the bats recognise and locate the flowers. 

To test this idea they removed flowers from their usual position on the cactus stems and placed them in another part of the stem that did not have the hairy patch.  They found the flowers’ echoes were lost amongst the echoes from the rest of the cactus stem, which made it difficult to locate the flowers from reflected sound alone.  However, the flowers in their normal place surrounded by the sound absorbing hairy surface stood out. 

The research team concluded: “Our results indicate that, instead of making flowers more reflective, plants can also evolve structures to attenuate the background echo, thereby enhancing the acoustic contrast with the target.”

References: Inside JEB 3 March 2023; Journal of Experimental Biology 3 March 2023 doi: 10.1242/jeb.245263.

Editorial Comment:  When evolutionists write throwaway lines such as “plants can evolve structures” we need to challenge them with “How?”  Natural selection is a non-answer! Natural selection only selects what is already there.  

So, how would a plant know what frequency the bats’ sonar signals operate; how would it know what structures would absorb this sound; how would it know how to changes it growth control genes to make the hairy surface; and how did it get all this right in one generation so that the plant did not die out from lack of pollination?

It is far more logical to believe that the Creator who made all living things made the bats and the plants to work together in this complementary way to provide the bats with nectar and enable the plants to be pollinated. 

Creation Research News 4 April 2023

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