Rosa Rubicondior

Friday 23 August 2024

Malevolent Design - How The Malevolent Designer Perfected The Mosquito As Its Favourite Parasite Delivery System

Mosquitoes sense infrared from body heat to help track humans down | The Current

To an intelligent [sic] design creationists it must seem that the mosquito is the divine malevolence's delivery system of choice for getting its parasites into as many people as possible to maximise the suffering in the world.

There are others of course, such as the tsetse fly that delivers the parasite that causes sleeping sickness to humans and their cattle, which is probably the major reason Africans never developed agriculture, and ticks do their bit in spreading diseases too, but none are as effective as the mosquito which is responsible for transmitting parasites that cause the deaths of half a million or more people annually.

The World Health Organization has estimated that malaria alone causes 400,000 deaths a year, mostly children, then there is dengue, yellow fever, zika and several other diseases transmitted by the female mosquito when she takes a blood meal. To keep the blood flowing she first injects saliva which contains an anticoagulant. It also contains viruses and microorganisms such as Plasmodium falciparum.

What viruses and parasites are female mosquitoes the vectors for and how do these affect the human population? Female mosquitoes are notorious vectors for several viruses and parasites that significantly impact human health. Here’s an overview of the main pathogens they transmit and their effects on the human population:

Malaria

Pathogen: Plasmodium parasites (primarily Plasmodium falciparum, P. vivax, P. ovale, and P. malariae)
Vector: Anopheles mosquitoes
Effect on Humans: Malaria is one of the deadliest diseases transmitted by mosquitoes, causing symptoms like fever, chills, and flu-like illness. Severe cases can lead to anemia, cerebral malaria, and death. Malaria remains a major public health problem, particularly in sub-Saharan Africa, causing over 600,000 deaths annually, most of which are children under five years old.

Dengue Fever

Pathogen: Dengue virus (DENV), which has four serotypes (DENV-1 to DENV-4)
Vector: Aedes aegypti and Aedes albopictus mosquitoes
Effect on Humans: Dengue fever causes high fever, severe headache, pain behind the eyes, joint and muscle pain, and rash. Severe forms, such as dengue hemorrhagic fever and dengue shock syndrome, can be fatal. Dengue is a major cause of illness in tropical and subtropical regions, with an estimated 100 million cases occurring annually.

Zika Virus

Pathogen: Zika virus (ZIKV)
Vector: Aedes aegypti and Aedes albopictus mosquitoes
Effect on Humans: Zika virus usually causes mild symptoms like fever, rash, and joint pain. However, it can cause severe birth defects, particularly microcephaly, when a pregnant woman is infected. Zika outbreaks have occurred in Africa, Southeast Asia, and the Pacific Islands, with the most notable outbreak occurring in Brazil in 2015-2016.

Chikungunya

Pathogen: Chikungunya virus (CHIKV)
Vector: Aedes aegypti and Aedes albopictus mosquitoes
Effect on Humans: Chikungunya causes fever and severe joint pain, often leading to chronic pain that can last for months or even years. The disease is rarely fatal, but it significantly impacts quality of life. It has caused numerous outbreaks in Africa, Asia, and the Americas.

Yellow Fever

Pathogen: Yellow fever virus (YFV)
Vector: Aedes aegypti mosquitoes
Effect on Humans: Yellow fever can range from mild symptoms like fever and muscle pain to severe liver disease with bleeding and jaundice, often leading to death. The disease is endemic in tropical areas of Africa and Central and South America, and despite the availability of a vaccine, it still causes significant mortality in unvaccinated populations.

West Nile Virus

Pathogen: West Nile virus (WNV)
Vector: Culex species mosquitoes
Effect on Humans: West Nile virus can cause a range of symptoms, from mild fever to severe neurological diseases such as encephalitis and meningitis. While most infections are asymptomatic, severe cases can lead to long-term neurological damage or death. The virus is prevalent in Africa, Europe, the Middle East, and the Americas.

Lymphatic Filariasis (Elephantiasis)

Pathogen: Wuchereria bancrofti, Brugia malayi, and Brugia timori (parasitic worms)
Vector: Culex, Anopheles, and Aedes mosquitoes
Effect on Humans: Lymphatic filariasis is a debilitating disease that causes lymphedema (swelling due to lymphatic system blockage), leading to severe disability and social stigma. The condition, known as elephantiasis, causes the enlargement and hardening of limbs and genitals. It affects millions of people, primarily in tropical and subtropical regions.

Rift Valley Fever

Pathogen: Rift Valley fever virus (RVFV)
Vector: Various mosquito species, including Aedes and Culex
Effect on Humans: Rift Valley fever primarily affects animals, but humans can also contract the virus, leading to symptoms like fever, muscle pain, and in severe cases, hemorrhagic fever, encephalitis, or blindness. Outbreaks are often associated with heavy rainfall and flooding, particularly in sub-Saharan Africa.

Japanese Encephalitis

Pathogen: Japanese encephalitis virus (JEV)
Vector: Culex species mosquitoes
Effect on Humans: Japanese encephalitis causes inflammation of the brain, leading to symptoms like fever, headache, vomiting, and neurological symptoms, including seizures and paralysis. It can be fatal or cause permanent neurological damage. The disease is endemic in parts of Asia and the Western Pacific.

Public Health Impact
The diseases transmitted by female mosquitoes have a profound impact on public health worldwide, particularly in tropical and subtropical regions. The economic burden includes the cost of medical treatment, lost productivity, and vector control programs. These diseases also contribute to poverty and hinder economic development in affected regions.

Efforts to combat mosquito-borne diseases include widespread vaccination campaigns (where vaccines are available), distribution of insecticide-treated bed nets, indoor residual spraying, and public health campaigns to reduce mosquito breeding sites. However, the control and eradication of these diseases remain challenging due to factors like insecticide resistance, climate change, and the rapid urbanization of tropical areas.

It is this act of injecting saliva which make the female mosquito such a dangerous insect, together with the fact that it seems to have salivary glands designed to contain the viruses and parasites.

But of course, to be really effective, the female mosquito must first find a victim. How she does this is the subject of a paper by A team led by researchers at the University of California Santa Barbara recently published, open access, in Nature and explained in a UC Sata Barbara News release:

Mosquitoes sense infrared from body heat to help track humans down
While a mosquito bite is often no more than a temporary bother, in many parts of the world it can be scary. One mosquito species, Aedes aegypti, spreads the viruses that cause over 100,000,000 cases of dengue, yellow fever, Zika and other diseases every year. Another, Anopheles gambiae, spreads the parasite that causes malaria. The World Health Organization estimates that malaria alone causes more than 400,000 deaths every year. Indeed, their capacity to transmit disease has earned mosquitoes the title of deadliest animal.

Male mosquitoes are harmless, but females need blood for egg development. It’s no surprise that there’s over 100 years of rigorous research on how they find their hosts. Over that time, scientists have discovered there is no one single cue that these insects rely on. Instead, they integrate information from many different senses across various distances.
A team led by researchers at UC Santa Barbara has added another sense to the mosquito’s documented repertoire: infrared detection. Infrared radiation from a source roughly the temperature of human skin doubled the insects’ overall host-seeking behavior when combined with \(\small \ce{CO2}\) and human odor. The mosquitoes overwhelmingly navigated toward this infrared source while host seeking. The researchers also discovered where this infrared detector is located and how it works on a morphological and biochemical level. The results are detailed in the journal Nature.

The mosquito we study, Aedes aegypti, is exceptionally skilled at finding human hosts. This work sheds new light on how they achieve this.

Dr. Nicolas DeBeaubien, co-lead author
Department of Molecular, Cellular, and Developmental Biology
University of California, Santa Barbara, CA, USA.

Guided by thermal infrared

It is well established that mosquitoes like Aedes aegypti use multiple cues to home in on hosts from a distance.

These include \(\small \ce{CO2}\) from our exhaled breath, odors, vision, [convection] heat from our skin, and humidity from our bodies. However, each of these cues have limitations.

Dr. Avinash Chandel, co-lead author
Department of Molecular, Cellular, and Developmental Biology
University of California, Santa Barbara, CA, USA.

The insects have poor vision, and a strong wind or rapid movement of the human host can throw off their tracking of the chemical senses. So the authors wondered if mosquitoes could detect a more reliable directional cue, like infrared radiation.

Within about 10 cm, these insects can detect the heat rising from our skin. And they can directly sense the temperature of our skin once they land. These two senses correspond to two of the three kinds of heat transfer: convection, heat carried away by a medium like air, and conduction, heat via direct touch. But energy from heat can also travel longer distances when converted into electromagnetic waves, generally in the infrared (IR) range of the spectrum. The IR can then heat whatever it hits. Animals like pit vipers can sense thermal IR from warm prey, and the team wondered whether mosquitoes, like Aedes aegypti, could as well.

The researchers put female mosquitoes in a cage and measured their host-seeking activity in two zones. Each zone was exposed to human odors and \(\small \ce{CO2}\) at the same concentration that we exhale. However, only one zone was also exposed to IR from a source at skin temperature. A barrier separated the source from the chamber prevented heat exchange through conduction and convection. They then counted how many mosquitoes began probing as if they were searching for a vein.

Adding thermal IR from a 34º Celcius source (about skin temperature) doubled the insects’ host-seeking activity. This makes infrared radiation a newly documented sense that mosquitoes use to locate us. And the team discovered it remains effective up to about 70 cm (2.5 feet).

What struck me most about this work was just how strong of a cue IR ended up being. Once we got all the parameters just right, the results were undeniably clear.

Dr. Nicolas DeBeaubien.

Previous studies didn’t observe any effect of thermal infrared on mosquito behavior, but senior author Craig Montell suspects this comes down to methodology. An assiduous scientist might try to isolate the effect of thermal IR on insects by only presenting an infrared signal without any other cues. “But any single cue alone doesn’t stimulate host-seeking activity. It’s only in the context of other cues, such as elevated \(\small \ce{CO2}\) and human odor that IR makes a difference,” said Montell, the Duggan and Distinguished Professor of Molecular, Cellular, and Developmental Biology. In fact, his team found the same thing in tests with only IR: infrared alone has no impact.

A trick for sensing infrared

It isn’t possible for mosquitoes to detect thermal infrared radiation the same way they would detect visible light. The energy of IR is far too low to activate the rhodopsin proteins that detect visible light in animal eyes. Electromagnetic radiation with a wavelength longer than about 700 nanometers won’t activate rhodopsin, and IR generated from body heat is around 9,300 nm. In fact, no known protein is activated by radiation with such long wavelengths, Montell said. But there is another way to detect IR.

Consider heat emitted by the sun. The heat is converted into IR, which streams through empty space. When the IR reaches Earth, it hits atoms in the atmosphere, transferring energy and warming the planet. “You have heat converted into electromagnetic waves, which is being converted back into heat,” Montell said. He noted that the IR coming from the sun has a different wavelength from the IR generated by our body heat, since the wavelength depends on the temperature of the source.

The authors thought that perhaps our body heat, which generates IR, might then hit certain neurons in the mosquito, activating them by heating them up. That would enable the mosquitoes to detect the radiation indirectly.

Scientists have known that the tips of a mosquito’s antennae have heat-sensing neurons. And the team discovered that removing these tips eliminated the mosquitoes’ ability to detect IR.

Indeed, another lab found the temperature-sensitive protein, TRPA1, in the end of the antenna. And the UCSB team observed that animals without a functional trpA1 gene, which codes for the protein, couldn’t detect IR.

Pits at the end of the mosquito’s antennae shield the peg-like structures that detect thermal IR.

Photo Credit: deBeaubien and Chandel et al.

The tip of each antenna has peg-in-pit structures that are well adapted to sensing radiation. The pit shields the peg from conductive and convective heat, enabling the highly directional IR radiation to enter and warm up the structure. The mosquito then uses TRPA1 — essentially a temperature sensor — to detect infrared radiation.

Diving into the biochemistry

The activity of the heat-activated TRPA1 channel alone might not fully explain the range over which mosquitoes were able to detect IR. A sensor that exclusively relied on this protein may not be useful at the 70 cm range the team had observed. At this distance there likely isn’t sufficient IR collected by the peg-in-pit structure to heat it enough to activate TRPA1.

Fortunately, Montell’s group thought there might be more sensitive temperature receptors based on their previous work on fruit flies in 2011. They had found a few proteins in the rhodopsin family that were quite sensitive to small increases in temperature. Although rhodopsins were originally thought of exclusively as light detectors, Montell’s group found that certain rhodopsins can be triggered by a variety of stimuli. They discovered that proteins in this group are quite versatile, involved not just in vision, but also in taste and temperature sensing. Upon further investigation, the researchers discovered that two of the 10 rhodopsins found in mosquitoes are expressed in the same antennal neurons as TRPA1.

Knocking out TRPA1 eliminated the mosquito’s sensitivity to IR. But insects with faults in either of the rhodopsins, Op1 or Op2, were unaffected. Even knocking out both the rhodopsins together didn’t entirely eliminate the animal’s sensitivity to IR, although it significantly weakened the sense.

Their results indicated that more intense thermal IR — like what a mosquito would experience at closer range (for example, around 1 foot) — directly activates TRPA1. Meanwhile, Op1 and Op2 can get activated at lower levels of thermal IR, and then indirectly trigger TRPA1. Since our skin temperature is constant, extending the sensitivity of TRPA1 effectively extends the range of the mosquito’s IR sensor to around 2.5 ft.

A tactical advantage

Half the world’s population is at risk for mosquito-borne diseases, and about a billion people get infected every year, Chandel said. What’s more, climate change and worldwide travel have extended the ranges of Aedes aegypti beyond tropical and subtropical countries. These mosquitoes are now present in places in the US where they were never found just a few years ago, including California.

The team’s discovery could provide a way to improve methods for suppressing mosquito populations. For instance, incorporating thermal IR from sources around skin temperature could make mosquito traps more effective. The findings also help explain why loose-fitting clothing is particularly good at preventing bites. Not only does it block the mosquito from reaching our skin, it also allows the IR to dissipate between our skin and the clothing so the mosquitoes cannot detect it.

Loose fitting clothing lets through less IR.
Photo Credit: deBeaubien and Chandel et al.

Despite their diminutive size, mosquitoes are responsible for more human deaths than any other animal. Our research enhances the understanding of how mosquitoes target humans and offers new possibilities for controlling the transmission of mosquito-borne diseases.

Dr. Nicolas DeBeaubien
In addition to the Montell team, Vincent Salgado, formerly at BASF, and his student, Andreas Krumhotz, contributed to this study.

The technical details will tell creationists just how clever their favourite malevolence has been in its mosquito design:

Abstract
Mosquito-borne diseases affect hundreds of millions of people annually and disproportionately impact the developing world^1,2. One mosquito species, Aedes aegypti, is a primary vector of viruses that cause dengue, yellow fever and Zika. The attraction of Ae. aegypti female mosquitos to humans requires integrating multiple cues, including \(\small \ce{CO2}\) from breath, organic odours from skin and visual cues, all sensed at mid and long ranges, and other cues sensed at very close range^3,4,5,6. Here we identify a cue that Ae. aegypti use as part of their sensory arsenal to find humans. We demonstrate that Ae. aegypti sense the infrared (IR) radiation emanating from their targets and use this information in combination with other cues for highly effective mid-range navigation. Detection of thermal IR requires the heat-activated channel TRPA1, which is expressed in neurons at the tip of the antenna. Two opsins are co-expressed with TRPA1 in these neurons and promote the detection of lower IR intensities. We propose that radiant energy causes local heating at the end of the antenna, thereby activating temperature-sensitive receptors in thermosensory neurons. The realization that thermal IR radiation is an outstanding mid-range directional cue expands our understanding as to how mosquitoes are exquisitely effective in locating hosts.

Main
Aedes aegypti is an invasive mosquito species that transmits flaviviruses, impacting a growing proportion of the world’s population^1,2. As female mosquitoes blood feed multiple times, they often shuttle viruses causing diseases ranging from dengue to yellow fever, Zika and chikungunya2. Ae. aegypti integrate multiple sensory cues to locate and navigate towards humans^3,4,5,6 (Fig. 1a). Integration is essential as any single stimulus is inadequate to differentiate humans from other targets. Detection of exhaled \(\small \ce{CO2}\) elevates their locomotor activity and increases their responsiveness to other host-derived stimuli, such as visual cues^3,4,5,6. However, Ae. aegypti has poor visual acuity, limiting its usefulness in discriminating between people and other hosts⁷. Organic olfactory cues are particularly important for finding humans. However, the efficacy of \(\small \ce{CO2}\) and olfactory cues in providing directional information is limited by air-current disturbances that exceed the mosquito’s flight speed, or if the host is moving quickly⁸. When mosquitoes are very close to the skin surface, they detect moisture and convective body heat^4,9.

Fig. 1: Set-up for testing IR radiation as a potential host-associated cue.

a, Known host-associated sensory cues. b, Modes of thermal energy transfer: convection, conduction and IR radiation. The peak emission wavelength (λ^M) of emitting bodies at 34 °C is around 9.4 µm. c, The host-associated cues presented during the assay: human odour, 5% (v/v) \(\small \ce{CO2}\) and heat in the form of IR radiation. Assay cages were 4 cm from the arena wall that housed the Peltier device to mitigate the effect of convective cues. Human odour was applied uniformly on the outside of the mesh of the assay cage from a used nitrile glove. \(\small \ce{CO2}\) was delivered through perforated tubing, which formed a perimeter around both the control and IR zones. d, The Peltier device housing. An IR-transparent polyethylene (PE) film blocked convective cues from reaching the mosquitoes. e, Schematic of the behavioural assay. Mosquitoes were presented with IR and their host-seeking behaviour was video recorded for 5 min. f, Representative video frame taken from an experiment in which females were exposed to human odour and 5% \(\small \ce{CO2}\). One zone was exposed to 34 °C radiant heat from a Peltier device. The Peltier device behind the other zone was off, and equilibrated to the ambient temperature (temp.) (29.5 °C). The position of each host-seeking mosquito was recorded during the experimental window. In all of the experiments in which \(\small \ce{CO2}\) was provided, it was applied using the indicated time series (in seconds) unless otherwise stated. g, The PI, calculated from the indicated formula, using the total number of host-seeking observations in each zone during the 5 min experiment. PI < 0 indicates preference for zone 1; PI > 0 indicates preference for zone 2.
Thermal energy is transferred through conduction, convection and radiation (Fig. 1b). Mosquito attraction to heat depends at least in part on the antenna^10,11. The terminal antennal segment contains neurons that respond to cooling and warming^12,13,14,15. Conduction requires contact and is not useful during host-seeking flight. Convective currents move upwards and are sensed only at distances of less than 10 cm (ref. ¹⁶). Detecting convective heat from hosts at short range is promoted by a general attraction to warmth, and by avoiding both cool and very hot temperatures¹⁷. Elimination of either of two ionotropic receptors from cooling-responsive neurons impairs attraction to convection heat^14,18. Moreover, disruption of the Aedes TRPA1 channel impairs avoidance of very hot temperatures at close range (50−60 °C), but does not impair the responses to surfaces ≤45 °C (ref. ¹⁷). The neurons that depend on TRPA1 for avoiding noxious heat remain to be identified. In Anopheles gambiae, trpA1 is expressed at the antennal tip15, although its thermosensory role is unclear.

Conductive heat requires contact, and convective heat is sensed at close range16. Thus, if mosquitoes sense thermal IR radiation, then surface body temperature could be detected at greater distances, as radiant heat is not limited by the physical constraints of convection and conduction. Thermal IR emitted by humans (~34 °C skin surface) has a peak emission wavelength of around 9.4 μm, with 90% of its energy between 3–30 μm (ref. ¹⁹). This electromagnetic radiation is much lower energy than the ~300–700 nm wavelengths that activate rhodopsins²⁰. Thus, if mosquitoes detect thermal IR, this sensation should not rely on phototransduction.

Few animals are thought to sense IR for navigation or sensing prey. These include rattlesnakes^21,22, certain beetles^23,24, western conifer seed bugs²⁵, kissing bugs and ticks^26,27. By contrast, it has been reported that mosquitoes, including Ae. aegypti, are not attracted to IR^9,28,29 However, in these studies, thermal IR was presented alone rather than in the presence of other host-associated stimuli^9,28,29. Given the importance of multisensory integration in host seeking^3,4,5,6, we wondered whether mosquitoes might exhibit attraction to thermal IR, but only in combination with other host cues.

[…]

Discussion
The finding that thermal IR is an important cue that Ae. aegypti females use to find their targets counters reports that Ae. aegypti do not respond behaviourally to thermal IR^9,28,29. However, previous research examined IR in isolation. Ae. aegypti require multisensory integration to home in on people, and individual human-associated cues, such as IR, \(\small \ce{CO2}\) plumes and organic odours, have little efficacy in stimulating host-seeking behaviour on their own^3,4,5,6. Our finding that IR is used in combination with other cues adds critical breadth to the Aedes toolkit—allowing them to home in on humans from mid-range distance in varied and dynamic environments.

The thermal IR that emanates from surface body temperature is far lower in energy than the longest wavelengths that activate visual pigments²⁰. Rather than detecting photons directly, a more plausible mechanism for thermal IR detection is that the radiant energy warms dendrites in coeloconic sensilla near to the tip of the antenna, which in turn activates thermosensitive receptors. In support of this model, removal of the distal portion of the antenna, which contains heat-sensitive neurons^12,13,15, eliminates IR attraction. While past research reports that the coeloconic sensilla at the distal end of the antenna sense convective heat¹³, the design of the thermosensitive peg-in-pit coeloconic sensilla at the antennal tip is more consistent with a sensor of radiant than of convective heat. Located in a pit, the neurons would be largely protected from convective currents, and would receive radiant heat preferentially from the direction of the pit aperture. Directionality is important for a radiant heat sensor, but would reduce the sensitivity of a convective heat sensor. Nevertheless, at very close range, the neurons in peg-in-pit sensilla would also be activated by convection heat.

We propose that IR impinging on the peg-in-pit sensilla is partially absorbed by the cuticle, and then energy is transferred to the endolymph through conduction. Some IR might also penetrate the cuticle and directly warm the endolymph. We found that the heat-activated TRPA1 channel is expressed in neurons at the antennal tip and is required for responding to IR. By contrast, trpA1 mutants display normal attraction to conductive/convective heat in the temperature range of human skin¹⁷. In the presence of conductive/convective heat, the role for TRPA1 is to help to avoid ≥50 °C conditions (ref. ¹⁷), even though TRPA1 is activated with a threshold of only around 32 °C (ref. ⁴¹). The anatomical location for this close-range TRPA1 function appears to be distinct from IR sensation. Our data support the model that TRPA1 senses IR at mid-range distances (~0.7 m) through the ‘warming neurons’ in the peg-in-pit sensilla.

Two opsins (op1, op2) and trpA1 are co-expressed at the end of the antenna, and mutations eliminating these opsins reduce IR sensation, but only at lower intensities of radiant heat. We propose that contributions of both opsins and TRPA1 to detecting radiant heat endows mosquitoes with a greater dynamic range for sensing radiant heating. We suggest that, at higher IR intensities, the radiant heat is sufficient to directly activate TRPA1, while, at lower levels of thermal IR, activation of the opsins initiates a cascade that amplifies the signal and indirectly activates TRPA1.

In conclusion, thermal IR represents an important mid-range cue that is used by Ae. aegypti to couple longer- and shorter-range cues. As An. stephensi are also attracted to thermal IR, we speculate that detection of the IR may be widely used among blood-feeding mosquitoes to home in on warm-blooded hosts. Finally, the finding that thermal IR is an effective host-seeking cue raises the possibility of developing strategies to interfere with this attraction, and the opportunity to devise more effective mosquito baits (Supplementary Discussion).

Chandel, A., DeBeaubien, N.A., Ganguly, A. et al.
Thermal infrared directs host-seeking behaviour in Aedes aegypti mosquitoes. Nature (2024). https://doi.org/10.1038/s41586-024-07848-5

Copyright: © 2024 The authors.
Published by Springer Nature Ltd. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

Clearly, if we assume for the sake of argument that intelligent [sic] design creationism has any merit, a great deal of design perfection has gone into designing the ways in which mosquitoes find their victims and deliver their cargo of infectious parasites. Just in case any creationists feel tempted to suggest that delivering parasites to warm-blooded animals like humans was not the design purpose of mosquitoes, it should be pointed out that their putative designer is allegedly both omniscient and omnipotent so anything it designs is designed in full knowledge of what it will do and, if in the unlikely event of undesired outcome, scrapping the design and starting again should be well within the designer's capability, so we have to assume any outcome was intentional and the purpose of the design.

And of course, we can dismiss the traditional creationist excuse of 'genetic entropy' causing 'devolution' [sic] as Michael J Behe's excuse for parasites, since the clever design for finding a blood meal is distinctly advantageous for the mosquito and can't possibly be described as 'devolution'.

If we don't assume intelligent design, however, we are left with a mindless evolutionary process with no plan and no intent, malevolent or otherwise. We are left with a full and complete explanation of how and why mosquitoes have these abilities and why they infect us with parasites, so increasing the suffering in the world - there is no benevolent god organising it.

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This book presents the reader with multiple examples of why, even if we accept Creationism's putative intelligent designer, any such entity can only be regarded as malevolent, designing ever-more ingenious ways to make life difficult for living things, including humans, for no other reason than the sheer pleasure of doing so. This putative creator has also given other creatures much better things like immune systems, eyesight and ability to regenerate limbs that it could have given to all its creation, including humans, but chose not to. This book will leave creationists with the dilemma of explaining why evolution by natural selection is the only plausible explanation for so many nasty little parasites that doesn't leave their creator looking like an ingenious, sadistic, misanthropic, malevolence finding ever more ways to increase pain and suffering in the world, and not the omnibenevolent, maximally good god that Creationists of all Abrahamic religions believe created everything. As with a previous book by this author, "The Unintelligent Designer: Refuting the Intelligent Design Hoax", this book comprehensively refutes any notion of intelligent design by anything resembling a loving, intelligent and maximally good god. Such evil could not exist in a universe created by such a god. Evil exists, therefore a maximally good, all-knowing, all-loving god does not.

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Thursday 22 August 2024

Creationism Refuted - How We Inherrited Part Of Our Anti-Viral Immune Response From A Microbial Ancestor

A comparison of immune proteins called viperins from Asgard archaea (left) and from a group of more complex life that includes humans, called eukaryotes (right). The three-dimensional shapes (a.k.a. structures) are strikingly similar, suggesting they also function similarly.

Credit: Pedro Leão.

Next Time You Beat a Virus, Thank Your Microbial Ancestors | College of Natural Sciences

Multicellular organisms are collections of specialised eukaryote cells, which are themselves collections of prokaryote cells that have been around for several billion years before getting together to form more complex cells.

And those prokaryote cells - bacteria and archaea - had had to cope with viruses which arose as soon as there were replicating assemblages of DNA for them to parasitize and co-opt the replication mechanism to make more copies of themselves.

The result was one of the first evolutionary arms races as the prokaryotes evolved ways to prevent themselves being parasitised and viruses evolved ways to overcome the microbes defences.

And, or course, the later eukaryote, complex cells that were to form the multicellular organisms inherited these antiviral defences and carried on the arms race with viruses, so it makes sense to find some of the remnants of these microbial defences, probably modified, inside our own cells, and forming a first line of defences.

This is a simple prediction of the Theory of Evolution and the resulting descent with modification from a common ancestor from billions of years ago.

What information do you have on the anti-viral proteins, Asgard Viperin and Eukaryote Viperin? Asgard Viperin and Eukaryote Viperin are both antiviral proteins that play crucial roles in the innate immune response, particularly in targeting and neutralizing viral infections. They belong to a broader family of proteins called Viperin (virus inhibitory protein, endoplasmic reticulum-associated, interferon-inducible). Viperin is a well-known antiviral protein that is highly conserved across various species, including archaea, bacteria, and eukaryotes. Here's a breakdown of what is known about Asgard Viperin and Eukaryote Viperin:

Asgard Viperin

Origin: Asgard Viperin is derived from the Asgard archaea, a group of microorganisms that are thought to be closely related to the last common ancestor of archaea and eukaryotes. These archaea were discovered in deep-sea hydrothermal vent environments and are considered important in studying the evolution of complex life forms.
Function: Asgard Viperin has been identified as an antiviral protein that provides insights into the ancient mechanisms of immune defense. Its function is similar to that of Viperin in eukaryotes, where it inhibits viral replication by targeting viral components or the cellular machinery viruses depend on for replication.
Structure and Mechanism: Like other Viperins, Asgard Viperin is likely to have a radical SAM (S-adenosylmethionine) domain, which is critical for its antiviral activity. This domain allows the protein to produce a reactive radical species, which can interfere with viral processes, such as the synthesis of nucleotides that viruses require for replication.
Evolutionary Significance: The discovery of Asgard Viperin highlights the ancient origins of antiviral defense mechanisms. It suggests that the strategies used by modern eukaryotic cells to combat viruses may have deep evolutionary roots.

Eukaryote Viperin

Origin: Eukaryote Viperin is found in eukaryotic organisms, including humans. It is one of the interferon-stimulated genes (ISGs) that are upregulated in response to viral infection. This protein is highly conserved across various species, from simple eukaryotes like algae to complex organisms like mammals.
Function: In eukaryotes, Viperin is a key player in the innate immune response. It exerts its antiviral effects through multiple mechanisms, depending on the type of virus. For example:

Inhibition of Viral Replication: Viperin can interfere with the replication of viruses by altering lipid metabolism or disrupting the assembly of viral particles.
Interaction with Cellular Machinery: It can inhibit viral RNA polymerase, thereby preventing the replication of RNA viruses.
Modulation of Immune Response: Viperin can enhance the production of other antiviral molecules and modulate the signaling pathways involved in the immune response.

Mechanism of Action: The radical SAM domain is crucial for the antiviral activity of Viperin in eukaryotes. This domain facilitates the formation of a radical species that can interfere with the function of viral proteins or the host cell machinery that viruses exploit.
Clinical Relevance: Understanding the role of Viperin in the immune response has significant implications for developing antiviral therapies. Since Viperin is involved in the response to a wide range of viruses, enhancing its activity could be a potential strategy for treating viral infections.

Comparative Insights

The study of Asgard and Eukaryote Viperin provides valuable insights into the evolution of antiviral defense mechanisms. The presence of similar antiviral proteins in both archaea and eukaryotes suggests that these defense strategies are ancient and have been conserved throughout evolution.
While both Asgard and Eukaryote Viperin share functional similarities, their specific roles and mechanisms may differ due to the differences in their cellular environments and the types of viruses they encounter.

Research Significance

The discovery and study of Asgard Viperin contribute to our understanding of the origin of eukaryotic cells and their immune systems. It also opens up new avenues for research into the evolution of antiviral defenses and the development of new antiviral strategies based on ancient mechanisms.

Understanding these proteins, particularly in the context of their evolutionary history and their function in modern organisms, is crucial for advancing our knowledge of immune responses and the development of antiviral therapies.

And this is precisely what researchers in the College of Natural Science at The University of Texas at Austin have found. They have shown that the proteins Asgard Viperin from the Argard archaea and the Eukaryote viperin, possessed by eukaryotes including humans are structurally (and functionally) very similar.

Next Time You Beat a Virus, Thank Your Microbial Ancestors
Two of our key defenses against viruses have persisted for billions of years, arising before complex life.
When you get infected with a virus, some of the first weapons your body deploys to fight it were passed down to us from our microbial ancestors billions of years ago. According to new research from The University of Texas at Austin, two key elements of our innate immune system came from a group of microbes called Asgard archaea.

Specifically, viperins and argonautes, two proteins that are known to play important roles in the immune systems of all complex life — from insects to plants to humans — came from the Asgard archaea. Versions of these defense proteins are also present in bacteria, but the versions in complex life forms are most closely related to those in Asgard archaea, according to the new scientific study published in the journal Nature Communications.

This research bolsters the idea that all complex life, called eukaryotes, arose from a symbiotic relationship between bacteria and Asgard archaea.

It adds more support to the fact that the Asgards are our microbial ancestors. It says that not only did eukaryotes get all these rich structural proteins that we’ve seen before in Asgards, now it’s saying that even some of the defense systems in eukaryotes came from Asgards.

Associate Professor Brett J. Baker, senior author
Associate professor of integrative biology and marine science
Department of Integrative Biology
University of Texas at Austin, Austin, TX, USA.

The researchers identified for the first time a large arsenal of defense systems in archaea that were previously known only in bacteria.

When viperins detect foreign DNA, which might indicate a dangerous virus, they edit the DNA so that the cell can no longer make copies of the DNA, which stops the virus from spreading. When argonautes detect foreign DNA, they chop it up, also halting the virus. Additionally, in more complex organisms, argonautes can block the virus from making proteins in a process called RNA silencing.

Viral infections are one of the evolutionary pressures that we have had since life began, and it is critical to always have some sort of defense. When bacteria and archaea discovered tools that worked, they were passed down and are still part of our first line of defense.

Assistant Professor Pedro Leão, lead author
Department of Microbiology - RIBES
Radboud University, Nijmegen, The Netherlands.

The researchers compared proteins involved in immunity across the tree of life and found many closely related ones. Then they used an AI tool called ColabFold to predict whether ones that had similar amino acid sequences also had similar three-dimensional shapes (aka structures). (It’s the shape of a protein that determines how it functions.) This showed that variations of the viperin protein probably maintained the same structure and function across the tree of life. They then created a kind of family tree, or phylogeny, of these sister amino acid sequences and structures that showed evolutionary relationships.

A family tree of immune proteins called viperins from different organisms. Versions of viperin found in complex life forms, called eukaryotes (green), fit within the group of viperins from Asgard archaea (purple).

Credit: University of Texas at Austin.

Finally, the researchers took viperins from Asgard archaea genomes, cloned them into bacteria (so the bacteria would express the proteins), challenged the bacteria with viruses, and showed that Asgard viperins do in fact provide some protection to the modified bacteria. They survived better than bacteria without the immune proteins.

This research highlights the integral role cellular defenses must have played from the beginning of both prokaryotic and eukaryotic life. It also inspires questions about how our modern understanding of eukaryotic immunity can benefit from unraveling some of its most ancient origins.

Emily Aguilar-Pine, co-author Department of Integrative Biology
University of Texas at Austin, Austin, TX, USA.

It’s undeniable at this point that Asgard archaea contributed a lot to the complexity that we see in eukaryotes today, so why wouldn’t they also be involved in the origin of the immune system? We have strong evidence now that this is true.

Assistant Professor Pedro Leão

Other authors, all from UT, are Mary Little, Kathryn Appler, Daphne Sahaya, Kathryn Currie, Ilya Finkelstein and Valerie De Anda.

This work was supported by the Simons and Moore foundations (via the Moore-Simons Project on the Origin of the Eukaryotic Cell) and The Welch Foundation.

Abstract
Dozens of new antiviral systems have been recently characterized in bacteria. Some of these systems are present in eukaryotes and appear to have originated in prokaryotes, but little is known about these defense mechanisms in archaea. Here, we explore the diversity and distribution of defense systems in archaea and identify 2610 complete systems in Asgardarchaeota, a group of archaea related to eukaryotes. The Asgard defense systems comprise 89 unique systems, including argonaute, NLR, Mokosh, viperin, Lassamu, and CBASS. Asgard viperin and argonaute proteins have structural homology to eukaryotic proteins, and phylogenetic analyses suggest that eukaryotic viperin proteins were derived from Asgard viperins. We show that Asgard viperins display anti-phage activity when heterologously expressed in bacteria. Eukaryotic and bacterial argonaute proteins appear to have originated in Asgardarchaeota, and Asgard argonaute proteins have argonaute-PIWI domains, key components of eukaryotic RNA interference systems. Our results support that Asgardarchaeota played important roles in the origin of antiviral defense systems in eukaryotes.

Introduction
Organisms across the tree of life contain complex defense systems (DS) to battle viral infections^1,2,3. Over the past decade, dozens of new DS have been identified and characterized in bacteria, sparking a debate about a potential link between these systems and the origins of innate immune mechanisms in eukaryotes. More recently, protein components of bacterial NLR (Nucleotide-binding domain leucine-rich repeat), CBASS (Cyclic oligonucleotide-based antiphage signaling system), viperins (virus-inhibitory protein, endoplasmic reticulum-associated, interferon (IFN)-inducible), argonautes, and other DS have been shown to exhibit homology with proteins involved in the eukaryotic immune system⁴. Most of the research on prokaryotic defense systems has focused on bacteria, with archaea representing <3% of the genomes in these studies^5,6,7. Thus, very little is known about the diversity or evolution of these systems in archaea.

Recently, diverse novel genomes have been obtained belonging to the archaea most closely related to eukaryotes, commonly referred to as “Asgard” archaea, the phylum Asgardarchaeota⁸. In addition to being sister lineages to eukaryotes, these archaea also contain an array of genes that are hallmarks of complex cellular life involved in signal processing, transcription, and translocations, among other processes⁹. The Asgard archaea are descendants of the ancestral host that gave rise to eukaryotic life. One newly described order, the Hodarchaeales (within the Heimdallarchaeia class), shared a common ancestor with eukaryotes⁸. Here, we characterize defense systems in archaea and show that Asgard archaea have a broad array of these DS. We also show that Asgards contributed to the origins of innate immune mechanisms in eukaryotes.

Fig. 2: Evolutionary history and anti-phage activity of Asgard viperins.

A Phylogenetic analysis of viperins. Viperins phylogeny revealed ancestral links of eVip (eukaryotic viperin) with asVip (asgard viperin) (nodes marked in red), particularly those within the Heimdallarchaeia class (including Kariarchaeaceae (2), Heimdallarchaeaceae (3) and Hodarchaeales (5)). The size of the dots on the nodes is proportional to bootstrap values ranging between 60 and 100. B Structure-based homology of viperins. Consistent with the sequence homology-based phylogenetic tree, the eVip structure appears to have been inherited from asVip (red node). The darker green color represents reference sequences predicted experimentally. The size of the dots at the center of the nodes is proportional to bootstrap values ranging between 50 and 100. C Superposition of an eVip structure, predicted by X-ray diffraction (green), and the structural models of an asVip, archaeal viperin (arVip), and bacterial viperin (from left to right). The yellow color in the models emphasizes the high conservation of the viperin catalytic site across the tree of life. The information regarding bacteria, archaea, asgard archaea and eukaryotes in panels (A–C) are represented by the pink, blue, purple and green color respectively. D Anti-T7 phage activity of asVip in E. coli. Nine asVip (asVip 26,11,20,25,16,12,17,23,8) exhibited anti-viral activity as indicated by the p-values (*p < 0.05; **p < 0.01). E Anti-T7 phage activity of asVip after codon optimization for their expression in E. coli. One asVip from a Hodarchaeales organism provided protection against viral infection (asVip 19). The center line of each box plot denotes the median; the box contains the 25^th to 75^th percentiles. Black whiskers mark the 5th and 95^th percentiles. pVip34 is a prokaryotic viperin selected as a positive control from Bernheim et al.¹³. Each experimental condition includes, on average, 53 plaques pooled from three biological replicates. A two-tailed t-test was used to calculate statistical significance in figures (E, D).

Fig. 3: Evolutionary history of Asgard argonaute proteins.

A Phylogeny of long type argonaute proteins from archaea, bacteria, and eukaryotes with cyclases as outgroup (grey). B Structure-based homology of argonautes. C Structural alignment of asAgo5 and 4OLA (eAgo) MID and PIWI domains (left), and the graphic model of the corresponding alignments (right). Salmon regions on the alignment highlight strong conservation (low RMDS values). Red amino acids in the structural alignment, and their respective models represent the 4OLA conserved functional residues in MID and PIWI. The information regarding bacteria, archaea, asgard archaea and eukaryotes are represented by the pink, blue, purple and green color respectively. The size of the dots on the nodes is proportional to bootstrap values ranging between 70 and 100.

Leão, P., Little, M.E., Appler, K.E. et al.
Asgard archaea defense systems and their roles in the origin of eukaryotic immunity. Nat Commun 15, 6386 (2024). https://doi.org/10.1038/s41467-024-50195-2

Copyright: © 2024 The authors.
Published by Springer Nature Ltd. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

A highly-conserved antiviral protein across all eukaryote cells speaks loudly of common ancestry. The fact that a very similar protein is found in an "Asgard" archaea is strongly supportive of the theory that the fist eukaryote cells were alliances of bacteria and archaea and that the "Asgard" archaea contributed antiviral protection on this early eukaryote, showing common ancestry extending back beyond the first eukaryotes.

Of course, the less intelligent creationists will now be chanting 'Common Ancestry', but the more intelligent cultists would realise that that would mean the first eukaryote cells arose after Adam and Eve, because these antiviral proteins wouldn't have been needed until after 'Sin' had allowed viruses to 'devolve' by 'genetic entropy' (© Michael J. Behe), unless they don't understand how having an arms race with oneself is not the sign of an intelligent designer.

Humpbacks bubble netting.

Humpbacks Wield and Manufacture Tools – Hawaiʻi Institute of Marine Biology

The humpback whale, Megaptera novaeangliae, has one of the largest brains of any living species, beaten only by the larger blue whale, so it's not really surprising that it is yet another species that has been shown to do something that creationists like to use as 'proof' that humans are a special creation, apart from the rest of animal and plant life - the ability to manufacture and use tools.

As an aside, along with a fin whale, humpback whales are the only large whale species I have ever seen in the wild on a whale-watching trip from Boston, MA, USA about 12 years ago.

The tool they manufacture, then manipulate to give it maximum effect is the well-known 'bubble net', where a humpback circles round beneath a shoal of fish and blows a ring of bubbles which panic the fish into a tight group, through which the whale then rises with wide-open mouths, scooping hundreds or thousands of fish in a single mouthful. The process is repeated until the entire shoal has been consumed

At team of marine biologists from the Marine Mammal Research Program (MMRP) at University of Hawai'i, Hawaiʻi Institute of Marine Biology (HIMB) and the Alaska Whale Foundation (AWF) have shown that not only do the whales manufacture this tool but then shape it to give it maximal efficiency.

What can you tell me about humpback whales, Megaptera novaeangliae, and their hunting method of 'bubble netting'? Humpback whales, scientifically known as Megaptera novaeangliae, are large marine mammals famous for their acrobatic breaches and complex songs. These whales are found in oceans worldwide, migrating vast distances between feeding grounds in polar waters and breeding grounds in tropical or subtropical waters. Adult humpbacks typically range from 12 to 16 meters (39 to 52 feet) in length and can weigh up to 40 tons.

Bubble Netting: A Unique Hunting Strategy

One of the most fascinating aspects of humpback whale behavior is their unique hunting technique known as bubble net feeding or bubble netting. This cooperative and highly coordinated method is primarily used to catch krill and small fish, such as herring and mackerel, which are the whales' main prey.

How Bubble Netting Works:

Group Coordination:

Bubble netting is a collaborative effort usually involving a group of humpback whales, although sometimes a single whale can perform a simplified version. The number of whales involved can range from a few individuals to a dozen or more.

Creating the Net:

One or more whales swim in a circle beneath a school of fish, blowing bubbles from their blowholes. These bubbles form a cylindrical "net" that traps and corrals the fish towards the center. The whales swim in an upward spiral, often releasing a continuous stream of bubbles to create the net.

Herding the Prey:

The bubbles and the noise made by the whales disorient and concentrate the prey into a tight ball. Some whales may produce loud vocalizations to further confuse the fish and drive them into the center of the net.

The Final Strike:

Once the prey is trapped in the bubble net, the whales swim upward with their mouths open, engulfing thousands of fish or krill in a single gulp. Often, several whales will surface together with their mouths wide open, filtering the water through their baleen plates to capture the prey.

Significance and Adaptation:

Efficiency: Bubble netting is an incredibly efficient hunting strategy, allowing humpback whales to consume large amounts of prey with relatively little energy expenditure.
Communication: The whales must communicate and coordinate their movements precisely to perform this complex behavior, which involves a high level of social interaction and possibly even culture among groups.
Learning: Not all humpback whale populations engage in bubble netting. This behavior seems to be learned, passed down through generations, or shared between different groups of whales, indicating cultural transmission.

Bubble net feeding is a remarkable example of animal cooperation and ingenuity, showcasing the intelligence and adaptability of humpback whales in their quest for survival.

They have just published their finding, open access, in the journal Royal Society Open Science, and a press release explaining their work:

Humpbacks Wield and Manufacture Tools
In a study published today in Royal Society Open Science, researchers at the Marine Mammal Research Program (MMRP) at UH Hawaiʻi Institute of Marine Biology (HIMB) and Alaska Whale Foundation (AWF) consider a new designation of the humpback whales they study: tool wielders.

Researchers have known that humpback whales create “bubble nets” to hunt, but they have learned that the animals don’t just create the bubble nets; they manipulate this unique tool in a variety of ways to maximize their food intake in Alaskan feeding grounds. This novel research demystifies a behavior key to the whales’ survival and offers a compelling case for including humpbacks among the rare animals that manufacture and wield their own tools.
Many animals use tools to help them find food but very few actually create or modify these tools themselves. We discovered that solitary humpback whales in southeast (SE) Alaska craft complex bubble nets to catch krill, which are tiny shrimp-like creatures. These whales skillfully blow bubbles in patterns that form nets with internal rings, actively controlling details like the number of rings, the size and depth of the net, and the spacing between bubbles. This method lets them capture up to seven times more prey in a single feeding dive without using extra energy. This impressive behavior places humpback whales among the rare group of animals that both make and use their own tools for hunting.

Professor Lars Bejder, co-lead author
Director of MMRP
Marine Mammal Research Program
Hawaii Institute of Marine Biology
University of Hawaii at Manoa, Kaneohe, HI, USA.

Success in hunting is key for the whales’ survival. The population of humpback whales in SE Alaska overwinters in Hawaiʻi, and their energy budget for the entire year depends on their ability to capture enough food during summer and fall in SE Alaska. Unraveling the nuances of their carefully honed hunting technique sheds light on how migratory humpback whales consume enough calories to traverse the Pacific Ocean.

Advanced Tools & Partnerships are Key to Demystifying Whale Behavior

Marine mammals known as cetaceans include whales, dolphins, and porpoises, and they are notoriously difficult to study. Advances in research tools are making it easier to track and understand their behavior, and in this instance, researchers employed specialty tags and drones to study the whales’ movements from above and below the water.

We deployed non-invasive suction-cup tags on whales and flew drones over solitary bubble-netting humpback whales in SE Alaska, collecting data on their underwater movements. [The tools have incredible capability, but honing them takes practice]. Whales are a difficult group to study, requiring skill and precision to successfully tag and/or drone them.

William T. Gough, co-author
Marine Mammal Research Program
Hawaii Institute of Marine Biology
University of Hawaii at Manoa, Kaneohe, HI, USA.

The logistics of working in a remote location in SE Alaska brought its own challenges to the research.

We are so grateful to our research partners at the Alaska Whale Foundation (AWF) for their immense knowledge of the local area and the whales in that part of the world. This research would not have been possible without the strong collaborative effort with AWF.

Professor Lars Bejder.

More Insights and Improved Management to Come

Cetaceans throughout the globe face a slough of threats that range from habitat degradation, climate change and fisheries to chemical and noise pollution. One quarter of the 92 known cetacean species are at risk of extinction, and there is a clear and urgent need to implement effective conservation strategies on their behalf. How the animals hunt is key to their survival, and understanding this essential behavior makes resource managers better poised to adeptly monitor and conserve the feeding grounds that are critical to their survival.

This little-studied foraging behavior is wholly unique to humpback whales. It’s so incredible to see these animals in their natural habitat, performing behaviors that only a few people ever get to see. And it’s rewarding to be able to come back to the lab, dive into the data, and learn about what they’re doing underwater once they disappear from view.

William T. Gough.

With powerful new tools in researchers' hands, many more exciting cetacean behavioral discoveries lie on the horizon.
This is a rich dataset that will allow us to learn even more about the physics and energetics of solitary bubble-netting. There is also data coming in from humpback whales performing other feeding behaviors, such as cooperative bubble-netting, surface feeding, and deep lunge feeding, allowing for further exploration of this population’s energetic landscape and fitness.

Professor Lars Bejder.

What I find exciting is that humpbacks have come up with complex tools allowing them to exploit prey aggregations that otherwise would be unavailable to them. It is this behavioral flexibility and ingenuity that I hope will serve these whales well as our oceans continue to change.

Dr. Andy Szabo, c-lead author
AWF Executive Directo
Alaska Whale Foundation
Petersburg, AK, USA.

This groundbreaking work was made possible with support from Lindblad Expeditions - National Geographic Fund, the University of Hawaiʻi at Mānoa, and a Department of Defense (DOD) Defense University Research Instrumentation Program (DURIP) grant.

This study was conducted under a NOAA permit issued to Alaska Whale Foundation (no. 19703). All research was conducted under institution IACUC approvals.

Abstract
Several animal species use tools for foraging; however, very few manufacture and/or modify those tools. Humpback whales, which manufacture bubble-net tools while foraging, are among these rare species. Using animal-borne tag and unoccupied aerial system technologies, we examine bubble-nets manufactured by solitary humpback whales (Megaptera novaeangliae) in Southeast Alaska while feeding on krill. We demonstrate that the nets consist of internally tangential rings and suggest that whales actively control the number of rings in a net, net size and depth and the horizontal spacing between neighbouring bubbles. We argue that whales regulate these net structural elements to increase per-lunge prey intake by, on average, sevenfold. We measured breath rate and swimming and lunge kinematics to show that the resulting increase in prey density does not increase energetic expenditure. Our results provide a novel insight into how bubble-net tools manufactured by solitary foraging humpback whales act to increase foraging efficiency.

1. Introduction
Tool use can be broadly defined as ‘the external employment of an unattached environmental object to alter more efficiently the form, position, or condition of another object, another organism, or the user itself when the user holds or carries the tool during or just prior to use and is responsible for the proper and effective orientation of the tool’ [1]. While this definition is widely used, some researchers have also emphasized the purposeful nature of tool use [2] and the way tools serve as extensions of the body to solve problems for which evolution has not provided a specific morphological adaptation [3] as alternative perspectives on the phenomenon. This emphasis on intent and problem-solving highlights the role that animal cognition, innovation and ingenuity play in the evolution of tool use.

Several mammalian [2,4,5], avian [6,7], fish [8] and insect [9] lineages include species that use tools; however, while taxonomically widespread, tool-using species are relatively rare. Rarer still are species that manufacture and/or modify their tools. Well-studied examples include free-ranging chimpanzees (Pan troglodytes) and orangutans (Pongo abelii), who manufacture specialized tools for extracting insects and fruits [10–13]. Similarly, New Caledonian crows (Corvus moneduloides) and Goffin’s cockatoos (Cacatua goffiniana) manufacture wooden tools for extracting vegetation and seed matter [14–16]. Manufacturing tools in this way typically involves complex sequences of behaviour, such as selecting and detaching suitable vegetation, stripping bark and adjusting the resulting tool’s length and shape [14,17,18], to impose a novel, three-dimensional form onto natural material. This sophisticated, goal-directed behaviour, together with the comparatively large and complex brains that characterize tool-manufacturing species [19,20], has led researchers to suggest that the relative rareness of tool use and manufacture is cognitively constrained in its taxonomic distribution [11,15,19,21].

Humpback whales (Megaptera novaeangliae) are known to produce complex bubble structures— ‘bubble-nets’ [22–25]. They do so by releasing air from their blowhole as they swim in a circular path below the surface. The rising bubbles form vertical curtains that appear as one or more rings from above. Aspects of bubble-nets and net-producing whales suggest that whales manufacture these nets as foraging tools [2]. For example, the use of bubble-nets has been observed repeatedly in association with foraging in allopatric humpback whale populations [23,24,26–29]. Several researchers have noted differences in the size and shape of bubble-nets produced by whales between, and notably within, the same populations [24,25,30]. Some of these differences correlate with the number of individuals participating in the use of the net and/or the different types of prey they are targeting (e.g. Pacific herring (Clupea pallasii), juvenile salmon (Oncorhynchus spp.) and krill (Order: Euphausiacea) [24,25,30]), suggesting that whales can exert control over their structure. Indeed, humpback whales’ flexible, spindle-shaped bodies, elongated pectoral flippers with large, rounded tubercles on their leading edge and out-sized tails [29,31,32] probably provide them with sufficient maneuverability [33] to manufacture nets that increase foraging efficiency under specific conditions.

In this study, we use observations from individually feeding humpback whales manufacturing bubble-nets in Southeast Alaska to examine how whales employ these tools to increase their prey intake and/or to decrease their energetic expenditure. To do so, we incorporate unoccupied aerial systems (UAS, or ‘drones’) coupled with photogrammetry techniques and non-invasive animal-borne tags equipped with motion sensors and video cameras to characterize the behaviour of solitary net-producing humpback whales and the nets they produce. Specifically, we describe net features, such as bubble-net size, shape and inter-bubble distance (‘mesh size’, i.e. the horizontal spacing between neighbouring bubbles), and consider how these modifiable attributes can contribute to an increase in prey intake for net-producing whales versus non-net-producing foraging whales. We also examine breath rates, lunge kinematics and dive behaviour to explore potential energetic costs associated with deploying bubble-nets. In doing so, we provide novel insights into the benefits that tool use provides foraging whales.

Figure 1. Variables and data collected from UAS and tagging methodologies. (a) UAS-derived bubble-net metrics for a two-ring bubble-net, including the area and diameter for the inner ring, and the horizontal inter-bubble distance (i.e. mesh size) for the outer ring. (b) Whale-producing bubble pulses, showing (i) left flipper, (ii) previous bubble pulse and (iii) new bubble pulse. (c) Whale with mouth open immediately prior to a lunge, with (iv) top jaw, (v) baleen rack, (vi) bottom jaw and (vii) right flipper visible. (d) Whale approaching the surface after a lunge, with the (viii) mouth closed prior to breaking the water’s surface and (ix) full bubble-net visible.

Figure 2. Data-driven simulation of a humpback whale manufacturing a bubble-net. (a) A zoomed-out view of average krill layer depth demonstrates the three-dimensional trajectory of a bubble-net feeding humpback whale from the start (white) to the end (pink) of the dive. (b) The UAS imagery alongside concurrent data-driven pre-lunge simulation showing 0.6 m s^-1 rise rate of spherical cap leaders compared with 0.1 m s^-1 rise rate for trailing capillary bubbles.

Szabo, A.; Bejder, L.; Warick, H.; van Aswegen, M.; Friedlaender, A. S.; Goldbogen, J.; Kendall-Bar, J. M.; Leunissen, E. M.; Angot, M.; Gough, W. T.
Solitary humpback whales manufacture bubble-nets as tools to increase prey intake Royal Society Open Science; 11(8) 240328; DOI: 10.1098/rsos.240328

Copyright: © 2024 The authors.
Published by the Royal Society. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

So, another one is added to the growing list of species that have abilities that were once claimed by creationists as proof of the unique, special creation of humans; an ability that takes intelligence, planning and, in the case of these whales, culture, since not all pods (yet) have this ability. When performing this technique as a group, it also involves planning, strategic thinking and communication in order to precisely coordinate the behaviour of each member of the pod.

Since this is a culturally transmitted, learned behaviour, there must have been a time when the skill was being perfected by careful observation, planning and experimentation, which implies simple scientific methodology and evaluation of the results.

Refuting Creationism - Not Whether But How And Where - Scientists Reassess The Fossil Record Of Human Evolution

A human evolutionary tree. The dashed lines indicate that evolutionary relationships between species are uncertain. Note the 'bushiness' of the tree; the australopithecine line branches into several species of Australopithecus and also to several Homo species

Open University/Douglas Palmer and Patricia Ash

Fossil hotspots in Africa obscure a more complete picture of human evolution | Media Relations | The George Washington University

The Modern Theory of Evolution is not just an interpretation of the fossil record. It's not even an interpretation of the fossil record, but an explanation of the genetic, cladistic, physiological, anatomical and molecular evidence, all of which converge on the same explanation, supported by, but not dependent on, the fossil record.

That conclusion is species have evolved from earlier ancestors by a process of evolutionary divergence from common ancestors.

The problem of being too dependent on the fossil record, which is inevitable when the genetic, physiological and biochemical evidence is no longer available is that, because of the rarity of fossilisation which depends on a body finding itself in the right place at the right time, is that it is essentially a random sampling process which produces a snapshot of the population at that time and place, randomly placed both temporally and geographically.

With some places (and times) being more conducive to producing fossils, this snapshot can easily be biased in favour of particular places and times appearing to be more important to the evolutionary process than they were in reality. There are fossil hotspots because those places favoured fossilisation, not because more of the species were concentrated there or because something about that place influenced the evolution of the species.

Malevolent Designer News - How A Spider Manipulates Captured Firefles To Become Lures To Catch More Fireflies.

Abscondita terminalis

CC BY-NC 4.0.

Spider exploits firefly's flashing signals to lure more prey | ScienceDaily

Today comes news that may help cheer up those creationists who haven't managed to avoid all the unwelcome news for creationism that science keeps on producing. It's news of how, in a breathtaking display of brilliant nastiness, an orb web spider appears to have been designed to use captured fireflies to lure more fireflies to their death by manipulating the flashing light signals they display.

Mind you, this will make it harder for creationists to argue that their putative designer is one and the same god as the omnibenevolent creator god of the Bible and Qur'an. Along with the evidence of parasites, and especially parasites that turn their victims into zombies by taking control of their bodies, in some cases even after death, this news reinforces the impression of a hate-filled malevolent creator devising ever-more ingenious ways to kill its creation.

The spider/firefly news come from a team of researchers led by Xinhua Fu, from Huazhong Agricultural University, China. They found that male fireflies, which normally flash two lights in response to the female’s single flash, adopt the female signalling strategy when caught in the web of an orb web spider, Araneus ventricosus. What is not clear without further research is whether this is the result of being bitten by the spider or of simply being caught, but one way or another, it results in more male fireflies being lured to the spider's web.

This finding has just been published in the Cell Press journal Current Biology. It was also explained in information made available ahead of publication and reported in Science Daily:

Refuting Creationism - A Giant Millipede Gives Creationists The Creeps

Arthropleura fossil embedded in sandstone

Largest-ever fossil millipede found in Northern England | Department of Earth Sciences

An old story from December 2021, which I somehow missed, is currently being given another airing in the social media, so I'll take this opportunity to make up for my earlier oversight. It is the news that the largest known ancient arthropod was discovered on a Northumberland, UK, beach.

It is interesting not so much because it refuted creationism by living 326 million years before the Universe existed according to creationism, but because it could only have reached that size by living in a high-oxygen environment such as pertained in the Carboniferous Era.

The basic problem with all the arthropods is that they depend on passive diffusion to exchange gasses (oxygen (\(\small \ce{O2})\) and carbon dioxide (\(\small \ce{CO2})\)) with their environment via series of spiracles, so the rate of diffusion is proportional to the concentration of \(\small \ce{O2}\) and \(\small \ce{CO2}\) in the atmosphere. The millipedes partly overcome this limitation by being long and thin.

Tell me all about the giant arthropod, Arthropleura, please. Arthropleura was a fascinating and enormous prehistoric arthropod that lived during the Carboniferous Period, approximately 315 to 299 million years ago. It is one of the largest-known land-dwelling invertebrates ever to have existed, and it is often compared to modern-day millipedes due to its segmented, elongated body.

Physical Description

Arthropleura was a colossal creature, with some estimates suggesting it could reach lengths of up to 2.5 meters (about 8 feet) or more. Its body was composed of numerous jointed segments, each covered by a pair of armor-like plates called tergites. These segments gave Arthropleura a ribbed appearance and allowed it to move with surprising agility for its size. Unlike modern millipedes, which have numerous legs on each segment, Arthropleura's limbs were relatively small compared to its overall body size, though they were still numerous.

The exoskeleton of Arthropleura was likely made of chitin, a tough, protective material found in the exoskeletons of all arthropods. This exoskeleton provided protection from predators and may have played a role in retaining moisture, which would have been important for surviving in the terrestrial environments of the Carboniferous Period.

Habitat and Lifestyle

Arthropleura thrived in the lush, swampy forests that were prevalent during the Carboniferous Period. These forests were dominated by giant ferns, horsetails, and other primitive plants, which created a humid and oxygen-rich atmosphere. This high oxygen content in the Earth's atmosphere is believed to have been a key factor in allowing Arthropleura and other large arthropods to grow to such enormous sizes.

Arthropleura was likely an herbivore, feeding on the abundant plant material in its environment. Some evidence suggests it might have consumed decaying plant matter rather than live plants, making it more of a detritivore. Its large size would have allowed it to access a variety of food sources, from low-lying vegetation to fallen leaves and other organic debris.

Behavior and Movement

Despite its size, Arthropleura was likely a relatively fast-moving creature, capable of navigating through the dense undergrowth of its forested habitat. Its body structure suggests it moved in a serpentine or undulating manner, using its many legs to propel itself forward.

There is little direct evidence of Arthropleura's behavior, but its size and the structure of its exoskeleton suggest it had few natural predators. It may have relied on its size and the tough armor of its exoskeleton for defense, rather than speed or agility.

Extinction

Arthropleura went extinct at the end of the Carboniferous Period, around 299 million years ago. The reasons for its extinction are not entirely clear, but several factors may have contributed. The drying out of the Earth’s climate, the reduction in atmospheric oxygen levels, and the rise of new predators, such as early reptiles, could have all played a role in its decline.

Fossil Evidence

Fossils of Arthropleura are relatively rare, but they have been found in various parts of the world, including North America and Europe. These fossils usually consist of fragments of the exoskeleton, as the softer parts of the body did not fossilize well. However, trace fossils, such as footprints, have also been discovered, providing valuable information about how this giant arthropod moved and lived.

Significance

Arthropleura is significant not just because of its enormous size, but also because it represents a time when arthropods dominated the Earth’s ecosystems. Its existence during the Carboniferous Period is a testament to the unique environmental conditions of the time, particularly the high oxygen levels that allowed such giant invertebrates to thrive.

In summary, Arthropleura was an extraordinary giant millipede-like arthropod that lived in the Carboniferous forests. Its size, habitat, and extinction provide valuable insights into the evolutionary history of arthropods and the environmental changes that shaped life on Earth millions of years ago.

The fossil was discovered in January 2018, in a large block of sandstone that had fallen from the cliff in Howick Bay in Northumberland. Fortunately the block split open in such a way as to perfectly expose the fossil, where it was spotted by a formed PhD student.

The fossil was painstakingly extracted from the block of sandstone and taken to Cambridge University's Department of Earth Sciences where it was examined by a team led by Neil S Davis. The team’s findings were published in the Journal of the Geological Society and announced in a Cambridge University news release in December, 2021:

Largest-ever fossil millipede found in Northern England
The largest-ever fossil of a giant millipede – as big as a car – has been found on a beach in the north of England.

The fossil – the remains of a creature called Arthropleura – dates from the Carboniferous Period, about 326 million years ago, over 100 million years before the Age of Dinosaurs. The fossil reveals that Arthropleura was the largest-known invertebrate animal of all time, larger than the ancient sea scorpions that were the previous record holders.
The specimen, found on a Northumberland beach about 40 miles north of Newcastle, is made up of multiple articulated exoskeleton segments, broadly similar in form to modern millipedes. It is just the third such fossil ever found. It is also the oldest and largest: the segment is about 75 centimetres long, while the original creature is estimated to have measured around 2.7 metres long and weighed around 50 kilograms. The results are reported in the Journal of the Geological Society.

The fossil was discovered in January 2018 in a large block of sandstone that had fallen from a cliff to the beach at Howick Bay in Northumberland.

It was a complete fluke of a discovery. The way the boulder had fallen, it had cracked open and perfectly exposed the fossil, which one of our former PhD students happened to spot when walking by.

Neil S. Davies, First Author
Department of Earth Sciences
University of Cambridge, Cambridge, UK.

Unlike the cool and wet weather associated with the region today, Northumberland had a more tropical climate in the Carboniferous Period, when Great Britain lay near the Equator. Invertebrates and early amphibians lived off the scattered vegetation around a series of creeks and rivers. The specimen identified by the researchers was found in a fossilised river channel: it was likely a moulted segment of the Arthropleura’s exoskeleton that filled with sand, preserving it for hundreds of millions of years.

The fossil was extracted in May 2018 with permission from Natural England and the landowners, the Howick Estate.

It was an incredibly exciting find, but the fossil is so large it took four of us to carry it up the cliff face.

Finding these giant millipede fossils is rare, because once they died, their bodies tend to disarticulate, so it’s likely that the fossil is a moulted carapace that the animal shed as it grew. We have not yet found a fossilised head, so it’s difficult to know everything about them.

Neil S. Davies

The fossil was brought back to Cambridge so that it could be examined in detail. It was compared with all previous records and revealed new information about the animal’s habitat and evolution. The animal can be seen to have only existed in places that were once located at the Equator, such as Great Britain during the Carboniferous. Previous reconstructions have suggested that the animal lived in coal swamps, but this specimen showed Arthropleura preferred open woodland habitats near the coast.

There are only two other known Arthropleura fossils, both from Germany, and both much smaller than the new specimen. Although this is the largest Arthropleura fossil skeleton ever found, there is still much to learn about these creatures.
The great size of Arthropleura has previously been attributed to a peak in atmospheric oxygen during the late Carboniferous and Permian periods, but because the new fossil comes from rocks deposited before this peak, it shows that oxygen cannot be the only explanation.

The researchers believe that to get to such a large size, Arthropleura must have had a high-nutrient diet.

While we can’t know for sure what they ate, there were plenty of nutritious nuts and seeds available in the leaf litter at the time, and they may even have been predators that fed off other invertebrates and even small vertebrates such as amphibians

Neil S. Davies

Arthropleura animals crawled around Earth’s equatorial region for around 45 million years, before going extinct during the Permian period. The cause of their extinction is uncertain, but could be due to global warming that made the climate too dry for them to survive, or to the rise of reptiles, who out-competed them for food and soon dominated the same habitats.

The fossil will go on public display at Cambridge’s Sedgwick Museum in the New Year [2022].

Neil Davies is a Fellow of Churchill College, Cambridge. The research was supported in part by the Natural Environment Research Council.

The paper in the Journal of the Geological Society is still behind a paywall, so only the abstract is available:

Abstract
Arthropleura is a genus of giant myriapods that ranged from the early Carboniferous to Early Permian, with some individuals attaining lengths >2 m. Although most of the known fossils of the genus are disarticulated and occur primarily in late Carboniferous (Pennsylvanian) strata, we report here partially articulated Arthropleura remains from the early Carboniferous Stainmore Formation (Serpukhovian; Pendleian) in the Northumberland Basin of northern England. This 76 × 36 cm specimen represents part of an exuvium and is notable because only two comparably articulated giant Arthropleura fossils are previously known. It represents one of the largest known arthropod fossils and the largest arthropleurid recovered to date, the earliest (Mississippian) body fossil evidence for gigantism in Arthropleura, and the first instance of a giant arthropleurid body fossil within the same regional sedimentary succession as the large arthropod trackway Diplichnites cuithensis. The remains represent 12–14 anterior Arthropleura tergites in the form of a partially sand-filled dorsal exoskeleton. The original organism is estimated to have been 55 cm in width and up to 2.63 m in length, weighing c. 50 kg. The specimen is preserved partially in three dimensions within fine sandstone and has been moderately deformed by synsedimentary tectonics. Despite imperfect preservation, the specimen corroborates the hypothesis that Arthropleura had a tough, sclerotized exoskeleton. Sedimentological evidence for a lower delta plain depositional environment supports the contention that Arthropleura preferentially occupied open woody habitats, rather than swampy environments, and that it shared such habitats with tetrapods. When viewed in the context of all the other global evidence for Arthropleura, the specimen contributes to a dataset that shows the genus had an equatorially restricted palaeogeographical range, achieved gigantism prior to late Paleozoic peaks in atmospheric oxygen, and was relatively unaffected by climatic events in the late Carboniferous, prior to its extinction in the early Permian.

Davies, Neil S.; Garwood, Russell J.; McMahon, William J.; Schneider, Joerg W.; Shillito, Anthony P. (2021).
The largest arthropod in Earth history: insights from newly discovered Arthropleura remains (Serpukhovian Stainmore Formation, Northumberland, England). Journal of the Geological Society 179(3) jgs2021-115; DOI: 10.1144/jgs2021-115

© 2021 Geological Society of London.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.

It is, of course, a characteristic of these sorts of finds that they are corroborated by and in turn corroborate several different strands of evidence. Such a large arthropod, given what we know of arthropod respiration, could only have evolved and lived at a time when there was a high level atmospheric \(\small \ce{O2}\) and a plentiful supply of nutrient material. This places it in the Carboniferous, in exactly the age of the rock formation in which it was found. This corroborates the theory that the Carboniferous would have been when large arthropods would have existed, given what we know of evolutionary biology.

Although creationists will try to present that as circular reasoning, it is in fact exactly what we would expect because real events involving several different geological, climatological and biological processes have a causal relationship so will always be mutually corroborative, just as the extinction of these organisms will also coincide with geological and climatological changes that caused them.

This is as obvious as the prediction that the formation of lakes and rivers in the Sahara would have been when the climate was wetter and rainfall was higher, and conversely that wetter weather and higher rainfall in the Sahara would have resulted in the formation of lakes and rivers. Not circular; merely corroboratory.

Sadly for creationists, there are no such independent strands of evidence corroborating any of their claims - either magic creation of species without ancestors a few thousand years ago or a global genocidal flood a few thousand years later. In fact, what evidence there is, such as this fossil, utterly refutes creationism, which continues to be not only an evidence-free superstition but an inherited superstition which runs counter to the available evidence.

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