Some while ago Evolution News did an essay that discusses three examples of biological phenomena that far exceed anything that would have been necessary for fitness. The three are the Venus Flytrap, the stripes on a zebra, and the prodigious memory capability of the human brain. Here's what they said about the Venus Flytrap:
New work by researchers in Germany, published in Current Biology, shows that this plant can count! The team's video, posted on Live Science (see below), shows how the trigger hairs inside the leaves generate action potentials that can be measured by electrical equipment.Here's a video that shows the Venus Flytrap in action: How did such an astonishing ability, not just the ability to capture and digest prey but also the ability to count, ever evolve through blind, purposeless processes in a plant?
Experiments show that the number of action potentials generates different responses. Two action potentials are required to close the trap. When closed, the plant starts producing jasmonic acid. The third spike activates "touch hormones" that flood the trap with digestive juices. The fifth spike triggers uptake of nutrients.
The struggling insect will trigger some 50 action potentials. The more they come, the more the trap squeezes tighter and tighter, as if knowing it has a stronger prey. The squeezing presses the animal against the digestive juices, also allowing more efficient uptake of nutrients.
"It's not quite plant arithmetic, but it's impressive nonetheless," says Liz Van Volkenburgh of the University of Washington in Seattle. "The Venus flytrap is hardwired to respond in the way that's now being described," she says.
Wayne Fagerberg at the University of New Hampshire in Durham agrees. "Obviously it doesn't have a brain to go 'one, two, three, four'," he says. "Effectively, it's counting. It's just not thinking about it."
In our experience, "hardwired" things that can count and activate responses are designed. This elaborate mechanism, involving multiple responses that activate machines on cue, seems superfluous for survival. The Venus flytrap has photosynthesis; it can make its own food. The argument that it needs animal food because it lives in nutrient-poor soil is questionable; other plants, including trees, do fine without animal traps.
Regarding the capabilities of the brain, a topic also discussed in the Evolution News article, I'm reminded of a quip by philosopher Alvin Plantinga who was discussing the brain's extraordinary ability to do higher math and reflecting on the implausibility of such an ability being adequately explained by a process that merely shaped human brains for reproductive success. Plantinga observed dryly that, after all, it's only the rare graduate student whose prospects for reproductive success are enhanced by his ability to solve differential equations.
