Our next example is a plant. The Cuckoo Pint belongs to the Arum family. It is a common resident of damp English hedge bottoms. Its arrow shaped leaves, covered with dark blotches, emerge above the soil in the spring. Next to follow is a rounded striped green sheath, from the centre of which projects a tall, dimpled, rod. The whole plant is poisonous, especially the bright red berries which form in autumn.

If you were expecting to see a beautiful, sweet smelling flower on this lily-like plant, you would be disappointed. It does not seek bees or butterflies to fertilise its seeds, but flies, especially the kind of flies that breed in foul smelling sewage. Accordingly, it has an ingenious system to ensure the transfer of the male pollen from one plant to the female stigmas of the next one. For a few days the poker-like rod that projects from the heart of the plant secretes a powerful smell of bad meat. The attraction of this smell for flies is heightened by the fact that the rod (called the spadix) is actually many degrees higher in temperature than the surround­ing air, just as rotting material usually heats up. When a curious fly catches a whiff of this warm, ripe smell, it lands on the sheath and makes its way downwards into the cool interior of the flower, expecting to find a good place to lay its eggs. It has to push its way past a ring of downward-pointing hairs, but once it gets past them it finds it cannot get out again. In the base of the flower are the female stigmas. As the fly bumbles around, it transfers onto these any Arum pollen that it has brought in on its back. After a day, the stamens (the male, pollen bearing part of the flower, sited just below the ring of hairs), become mature, and dust the fly with this plant’s pollen. On the third day, the ring of hairs withers rapidly, and the fly discovers it is free to fly away. However, there is a strong probability it will be deceived by a second Cuckoo Pint, and be caught again, so passing on the pollen from the first flower to this new one.

 

Perfect for the Job

CaptureThere are several questions we must ask about this strange flower. Firstly, the bad smell. Most plants have a sweet smell, but this family does not need insects that seek nectar. Scientists have analysed the mol­ecules responsible for the smell in a similar Arum called Helicodiceros muscivorous. This Arum attracts blowflies. Using gas chromatography (a procedure for identifying chemical compounds) they found three sulphur based compounds (dimethyl monosulphide, dimethyl disulphide and dimethyl trisulphide) in the Arum smell, which are identical to those found in bad meat. In tests, blowflies were completely unable to distinguish between the Arum imitation smell and the genuine bad meat smell. How does a plant come to create a molecule which has nothing to do with plants, and quite different from the smells which normally attract insects, but just perfect for blowflies? And what about the high temperature of the spadix which can be 20 degrees Celsius higher than the surrounding air? It has been shown that the plant burns fats to generate this warmth, in a complex chemical reaction – just to enhance its attractiveness to its involuntary helpers. And how did the three-day trap system evolve, with the downward-pointing hairs living just long enough to confine the flies until they have been thoroughly dusted with pollen?

Again, we marvel at a system for reproduction that is perfect for its purpose. But it is based on three separate elements, each of which is essential for suc­cess. How could these features develop independently, without some kind of control? The coincidence of them appearing in a finished and useful state at the same time is too great to be realistic. Once again, the situation requires a Designer who can set a goal and work towards it.

Reproduced by kind permission of the Christadelphian Auxiliary Lecturing Society ( CALS) (To be continued)