The Atlas moth (
Attacus atlas) has a strong anti-bat acoustic decoy at the tip of its forewings. Composite image with photograph on right half and acoustic tomography on the left. Colour indicates echo strength on a dB scale and red indicates highest echo amplitude. Note the red highly reflecting stripe created by the rippled part of the wingtip.
Credit: Dr Thomas Neil and Professor Marc Holderied
September: Moth wingtips | News and features | University of Bristol
One of the several aspects of biology you can never get an intelligent [sic] design advocate (that's intelligent design, not an intelligent advocate as these are practically unknown) to address is that of what biologists call, 'evolutionary arms races' where two organisms, usually predator and prey, or parasite and host are in competition with one another, each seeking to gain an advantage over the others.
Classic examples of this are the giraffe and acacia trees, with the former evolving a long neck to reach the leaves acacia trees have grown a long trunk to put out of the reach of giraffes and cheetahs and gazelles where each has to run faster than the other, the cheetah to eat and the gazelles to live, so they both run very fast and yet cheetahs still catch end eat gazelles.
Photograph of the Atlas moth (
Attacus atlas). This large silkmoth has the strongest known wingtip decoy with ripples and folds.
Credit: Dr Thomas Neil
Another more recent example currently affecting us all, is that of the SARS-CoV-2 parasitic virus where new variants such as the δ variant currently causing a new, more severe, pandemic, have evolved to better overcome the immune systems in its human hosts - an immune system intelligent [sic] design advocates believe their beloved malevolence designed to protect us from the viruses and bacteria it designs to make us sick.
And now, courtesy of a team of scientists from Bristol University, we have the example of moths having a mechanism for diverting the attack of bats which have been given (allegedly) echolocation so they can detect moths.
More of that research in a moment; first a little about the bat/moth arms races, which I wrote about in my popular book,
The Unintelligent Designer: Refuting the Intelligent Design Hoax. Briefly, if you accept for
Photograph of the Chinese tussar moth (
Antheraea pernyi). This silkmoth has a strong wingtip decoy based on ripples.
Credit: Dr Thomas Neil
the sake of argument, the Creationist insistence that all things are designed by their putative designer god, you have to accept that moths became nocturnal to escape from diurnal predators that hunted them with vision, then it designed the echo-location systems of bats so they could 'see' moths in the dark, then it gave moths the ability to hear the ultrasonic echolocation signals of bats and so avoid them, then it gave bats echolocation frequencies that moths couldn't detect, etc, etc,
(See Jacobs, David;
Explainer: the evolutionary arms race between bats and moths; 2014).
Now the Bristol team has revealed a new twist in this arms race by some saturniid moth (the group that includes silkworm moths). They have shown that the forewings of these moths have special folds and ripples near the tips which act as super-reflectors of bat echolocation sounds, which either confuse the bat or deflect its attack to the tips of the forewings where it does relatively little harm compared to an attach directed at the head or body.
We have demonstrated that the folded and rippled wingtips on the forewings of some silkmoths act as acoustic decoys.
Structurally, the wingtips act as acoustic retroreflectors, reflecting sound back to its source from numerous angles, meaning a bat would be more likely to strike the wingtip over the more vulnerable body of the moth …
The results of this study introduce another exciting aspect to the story of the bat-moths acoustic arms race. We have identified a novel form of acoustic defense amongst silkmoths which may give them an advantage over hunting bats. Wider implications might include improved man-made anti radar and sonar decoy architectures.
Professor Marc Holderied, corresponding author,
School of Biological Sciences
University of Bristol, Bristol, UK
To quote from the Bristol University press release:
They also discovered that the ripples and folds of the forewing tips have evolved to act as hemispheric and corner retroreflectors respectively, meaning that they reflect sound strongly back to its point of origin. Coupled together, the folds and ripples of these wingtips cover a huge range of incident sounds angles, meaning that over the entire wingbeat cycle of a flying moth and most possible positions of an attacking bat, the wingtip would consistently produce the strongest echoes. The acoustic protection of wingtips is even stronger than that of common hindwing decoys.
It has previously been shown that some moths have long 'streamers' on their hind wings that have a similar purpose in that a bat's attack is directed to where it does least harm to the moth.
Towed acoustic decoys are a well-established defense amongst some silkmoths. These species have evolved elongated hindwings which terminate in a coiled and twisted end. The morphology of these elongated hindwings means that they generate very strong echoes, so much so that they will often divert a bat’s acoustic gaze towards them, away from the exposed body of the moth, causing the bat to strike the expendable tail of the moth or miss the moth all together.
Conclusive support for the idea that the forewing reflector is an acoustic decoy comes from our finding that acoustic forewing decoys always evolved as an alternative to acoustic hindwing decoys, with there being no species known to possess both.
Dr Thomas Neil, lead author
School of Biological Sciences
University of Bristol, Bristol, UK
It takes a special form of gullible credulity to believe that a single designer would design these many examples of arms races to be found in nature, and then to conclude that that single designer is supremely intelligent. It would make more sense, if there were indeed any evidence that magic can make species evolve in a special direction or can make chemistry and physics do things they couldn't do without it, that there was more than one intelligence involved here. However, Creationists are forbidden by religious dogma from believing in more than a single creator so their interpretation - what they laughably call 'scientific creationism' - must be shoe-horned into that religious superstition so it conforms with fundamentalist Christianity.
This is how we can tell that the notion of intelligent design is not an alternative science, like politically-motivated Creationist frauds pretend, but Bible literalism dressed up in a lab coat to try to impress people who neither understand science nor biology and whose parochial ignorance and cultural chauvinism preconditions them to fall for the false dichotomy fallacy that, if there is something science can't explain, the locally popular god must have done it. In this case, though, science not only can but does explain it very well, without resort to magical mysteries.
Thank you for sharing!