More to a Fly than Meets the Eye
Flies and spiders, members of the arthropod phylum, may seem small and “less evolved” than the larger members of the animal kingdom. One shouldn’t let size alone be the measure of ability.
- Fly supercomputer: Did you ever think of the brain of a fly as a high-speed computer? That’s what PhysOrg called it: “the minute brains of these aeronautic acrobats process visual movements in only fractions of a second.” If soccer players had eyes like that, they would be able to process their moves as if watching the ball in slow motion, the article said. Picture the tiny size of a fly brain and then think about this factoid: “one sixth of a cubic millimetre of brain matter contains more than 100,000 nerve cells – each of which has multiple connections to its neighbouring cells.” One subtitle in the article announced, “The brain of the fly beats any computer.” Take that, Android. Elaborating, the article continued, “albeit the number of nerve cells in the fly is comparatively small, they are highly specialized and process the image flow with great precision while the fly is in flight. Flies can therefore process a vast amount of information about proper motion and movement in their environment in real time – a feat that no computer, and certainly none the size of a fly’s brain, can hope to match.”
It has taken 50 years to be able to “examine the cellular construction of the motion detector in the brain of the fly.” The team at Max Planck Institute spoke of the fly brain in computer terms: “the neurobiologists discovered that the L2-cell transforms these data and in particular, that it relays information only about the reduction in light intensity to the following nerve cells. The latter then calculate the direction of motion and pass this information on to the flight control system.” Readers should note that the researchers were experimenting on fruit flies – among the tiniest of flying insects. It would seem there’s a lot more miniaturization possible in hand-held devices if humans could ever approach the miniaturized processing power in a fly brain. The article concluded, “scientists intend to examine – cell by cell – the motion detection circuitry in the fly brain to explain how it computes motion information at the cellular level. Their colleagues from the joint Robotics project are eagerly awaiting the results.”
- Firefly sync blink: A report in Live Science discussed fireflies that synchronize their flashes and concluded it has a sexual attraction function. While that may be so, it overlooks the processing requirements to synchronize biological light organs over space. It may be that “By flashing the same pattern simultaneously, male fireflies are sending out a clear, unified declaration of their species to the females,” but how can they do this? The article only briefly mentioned the “female firefly’s nervous system processes visual signals” and the benefit that synchronized “flash flirting” might provide the female out of an otherwise chaotic field of blinking lights.
An article in KnoxNews.com (Knoxville News Sentinel) reported on the work by scientists at Georgia Southern University and University of Connecticut on Smoky Mountains fireflies Photinus carolinus. These can do synchronized flashing “in near-perfect unison, like strings of Christmas lights in the night air.” This kind of “spectacular show” is rarely seen outside of southeast Asia. It had been anecdotally observed among American fireflies; now the team found and studied it.
A mathematician quoted by KnoxNews said that synchrony can arise from a few simple mathematic rules. Certainly, however, fast data processing is required for thousands of male fireflies to switch their lights on within a tenth of a second of each other – and that’s not even accounting for the wonder of organs that can produce nearly 100% efficient cold light on demand under sophisticated brain control. Knox News admitted that this is “an incompletely understood mystery”. Researcher Andrew Moiseff said, “It’s one of those things that just makes you go ’wow.’”
As for how this wonder arose, Moiseff told Live Science “They evolved to flash in synchronizing patterns as a solution to specific behavioral, environmental or physiological conditions.” His original paper in Science,1 however, only mentioned the “evolution of synchrony” in passing, with no elaboration on how that occurred.
- Spider eyes: If a jumping spider were our size, it would be among the scariest of creatures. With its three sets of eyes pointing front, side and rear, it looks like something out of a science-fiction thriller. Those eyes are far more capable than previously thought, reported PhysOrg.
The smaller front-pointing eyes were thought to be just secondary visual inputs. Scientists at Macquarie University in Australia found a way to blindfold the spiders (if one can imagine such a delicate experiment) leaving the secondary eyes to do the seeing. Then they tethered them and produced dots on a screen for them to follow, as well as flies to stalk. They found that the spiders were just as good at hunting with their secondary pair of eyes as with all six. Replicating the experiment on 52 individual spiders, they considered it “unexpected” that a “perfect predator,” could perform so well with the handicap. Even without their primary eyes, they could see things other animals had difficulty seeing. “We believe this pair of eyes could have been underestimated by scientists in the past, and may be the most versatile element of their visual system, providing both spatial acuity and motion detection,” they said.
What this implies is that the data processing of the visual inputs is correspondingly intricate. Daniel Zurek said, “It’s astonishing that these animals, which have a body length of just 12 millimetres and a brain a fraction of the size of a honeybee’s, have developed such a sophisticated visual system covering almost 360 degrees with such high resolution.” The multiple eyes help “divvy up different visual tasks,” he said: “it is likely that this modular approach helps the spider to handle the computational demands of vision.” Humans, with just two forward-looking eyeballs, seem visually deprived by comparison. But they will be glad to learn that the favorite prey of the jumping spider is the housefly.
1. Moiseff and Copeland, “Firefly Synchrony: A Behavioral Strategy to Minimize Visual Clutter,” Science, 9 July 2010: Vol. 329. no. 5988, p. 181, DOI: 10.1126/science.1190421.
The pattern in these amazing stories is always the same: (1) the sophistication is greater than anyone ever thought, and (2) evolution, if mentioned at all, is a pathetic afterthought tacked onto the story. It provides no explanatory power but is merely assumed. The evolution-talk is like a political poster pasted onto a building. It provides no foundation, support or function related to the building; it only distracts attention (i.e., “Long live King Charlie!”) from the intelligently designed architecture behind it.