Beetle-ant symbiosis in the dinosaur age


Detailed photos of the newly discovered Promyrmister kistneri beetle's morphology through its amber encasement. Credit: Courtesy of the Parker laboratory / eLife

From the California Institute of Technology in the USA:

These beetles have successfully freeloaded for 100 million years

Ancient beetle infiltrated earliest-known ant colonies like its modern relatives

April 17, 2019

Summary: An ancient and rare beetle fossil is the oldest example of a social relationship between two animal species.

Almost 100 million years ago, a tiny and misfortunate beetle died after wandering into a sticky glob of resin leaking from a tree in a region near present-day Southeast Asia. Fossilized in amber, this beetle eventually made its way to the desk of entomologist Joe Parker, assistant professor of biology and biological engineering at Caltech. Parker and his colleagues have now determined that the perfectly preserved beetle fossil is the oldest-known example of an animal in a behaviorally symbiotic relationship.

A paper describing the work appears on April 16 in the journal eLife.

Symbiotic relationships between two species have arisen repeatedly during animal evolution. These relationships range from mutually beneficial associations, like humans and their pet dogs, to the parasitic, like a tapeworm and its host.

Some of the most complex examples of behavioral symbiosis occur between ants and other types of small insects called myrmecophiles — meaning “ant lovers.” Thanks to ants’ abilities to form complex social colonies, they are able to repel predators and amass food resources, making ant nests a highly desirable habitat. Myrmecophiles display elaborate social behaviors and chemical adaptations to deceive ants and live among them, reaping the benefits of a safe environment and plentiful food.

Ants’ social behaviors first appear in the fossil record 99 million years ago, during the Cretaceous period of the Mesozoic era, and are believed to have evolved not long before, in the Early Cretaceous. Now, the discovery of a Cretaceous myrmecophile fossil implies that the freeloading insects were already taking advantage of ants’ earliest societies. The finding means that myrmecophiles have been a constant presence among ant colonies from their earliest origins and that this socially parasitic lifestyle can persist over vast expanses of evolutionary time.

“This beetle-ant relationship is the most ancient behavioral symbiosis now known in the animal kingdom,” says Parker. “This fossil shows us that symbiosis can be a very successful long-term survival strategy for animal lineages.”

The fossilized beetle, named Promyrmister kistneri, belongs to a subfamily of “clown” beetles (Haeteriinae), all modern species of which are myrmecophiles. These modern beetles are so specialized for life among ants that they will die without their ant hosts and have evolved extreme adaptations for infiltrating colonies. The beetles are physically well protected by a thick tank-like body plan and robust appendages, and they can mimic their host ants’ nest pheromones, allowing them to disguise themselves in the colony. They also secrete compounds that are thought to be pacifying or attractive to ants, helping the beetles gain the acceptance of their aggressive hosts. The fossilized Promyrmister is a similarly sturdy insect, with thick legs, a shielded head, and glandular orifices that the researchers theorize exuded chemicals to appease its primitive ant hosts.

Depending on another species so heavily for survival has its risks; indeed, an extinction of the host species would be catastrophic for the symbiont. The similarities between the fossilized beetle and its modern relatives suggest that the particular adaptations of myrmecophile clown beetles first evolved inside colonies of early “stem group” ants, which are long extinct. Due to Promyrmister’s remarkable similarity to modern clown beetles, Parker and his collaborators infer that the beetles must have “host switched” to colonies of modern ants to avoid undergoing extinction themselves. This adaptability of symbiotic organisms to move between partner species during evolution may be essential for the long-term stability of these intricate interspecies relationships.

What coelacanths tell about brain evolution


This 2 February 2018 video says about itself:

Diving With Coelacanths

This video is part of the banquet presentation given by Richard Pyle at the 2013 Marine Aquarium Conference of North America (MACNA) in Ft. Lauderdale, Florida. It represents a video overview of a series of dives conducted in 2011 off Sodwana Bay, South Africa, to find and film living Coelacanths.

The video also shows what the habitat looks like at depths of 100-120 meters (330-400 feet) off Sodwana Bay. The dives were led by Peter Timm, and filmed by Robert Whitton, Daniel Stevenson and Richard Pyle.

From the European Synchrotron Radiation Facility:

Coelacanth reveals new insights into skull evolution

April 17, 2019

An international team of researchers presents the first observations of the development of the skull and brain in the living coelacanth Latimeria chalumnae. Their study, published in Nature, provides new insights into the biology of this iconic animal and the evolution of the vertebrate skull.

The coelacanth Latimeria is a marine fish closely related to tetrapods, four-limbed vertebrates including amphibians, mammals and reptiles. Coelacanths were thought to have been extinct for 70 million years, until the accidental capture of a living specimen by a South African fisherman in 1938. Eighty years after its discovery, Latimeria remains of scientific interest for understanding the origin of tetrapods and the evolution of their closest fossil relatives — the lobe-finned fishes.

One of the most unusual features of Latimeria is its hinged braincase, which is otherwise only found in many fossil lobe-finned fishes from the Devonian period (410-360 million years ago). The braincase of Latimeria is completely split into an anterior and posterior portion by a joint called the “intracranial joint.” In addition, the brain lies far at the rear of the braincase and takes up only 1% of the cavity housing it. This mismatch between the brain and its cavity is totally unequalled among living vertebrates. How the coelacanth skull grows and why the brain remains so small has puzzled scientists for years. To answer these questions, researchers studied specimens at different stages of cranial development from several public natural history collections.

Although many specimens of adult coelacanths are available in natural history collections, earlier life stages such as fetuses are extremely rare. Scientists hence used state-of-the-art imaging techniques to visualize the internal anatomy of the specimens without damaging them. They notably digitalized a 5 cm-long fetus, the earliest developmental stage available for Latimeria, with synchrotron X-ray microtomography at the European Synchrotron (ESRF). Over the last two decades, the ESRF has developed unique expertise in designing non-invasive techniques widely used for evolutionary biology studies.

In addition, the researchers also imaged other stages with a powerful Magnetic Resonance Imaging (MRI) scanner at the Brain and Spine Institute (Paris, France), and a conventional X-ray micro-CTscan at the Muséum national d’Histoire naturelle (Paris, France). These data were used to generate detailed 3D models, which allowed scientists to describe how the form of the skull, the brain and the notochord (a tube extending below the brain and the spinal cord in the early stages of life) changes from a fetus to an adult.

They also observed how these structures are positioned relative to each other at each stage, and compared their observations with what is known about the formation of the skull in other vertebrates.

In contrast to most other vertebrates, where the notochord is replaced by the vertebral column early in embryonic development, the notochord expands considerably in Latimeria. The dramatic enlargement of the notochord likely influences the patterning of the braincase, and might underpin the formation of the intracranial joint. The brain might also be affected by the enlargement of the notochord, as relative size dramatically decreases during development.

These results illuminate for the first time the development of the living coelacanth skull and brain, and open up new avenues for research on the evolution of the vertebrate head.

Hugo Dutel, lead author and research associate in palaeobiology at the University of Bristol, UK, says, “These are very unique observations, but they represent only a tiny step forward compared to the amount we know on the development of other species. There are still more questions than answers! Latimeria still holds many clues for our understanding of vertebrate evolution, and it is important to protect this threatened species and its environment.”

British Conservative government represses climate change protesters


This 17 April 2019 video from Britain says about itself:

Extinction Rebellion: The People Risking Their Freedom To Stop Climate Change | HuffPost Reports: UK

In the midst of unprecedented warnings of climate breakdown, a new, radical protest group emerged in the UK in 2018 – Extinction Rebellion. Focusing on direct action and civil disobedience, Extinction Rebellion aim to disrupt daily life and confront government inaction on climate change. From their launch last year, we followed the group and witnessed its expansion.

By Laura Tiernan in Britain:

UK home secretary demands climate change protesters face “full force of the law”

20 April 2019

Mass arrests of climate change protesters continued in London yesterday, after the Conservative government’s Home Secretary Sajid Javid demanded police “use the full force of the law.”

More than 682 protesters have been arrested since Monday.

“No one should be allowed to break the law without consequence,” Javid tweeted Thursday morning. He called on police to “take a firm stance” against “any protesters who are stepping outside the boundaries of the law” and “significantly disrupting the lives of others.”

Javid’s statement followed well over 100 additional arrests in the centre of London Wednesday, after Scotland Yard demanded protesters be cleared from Parliament Square. Social media footage showed hundreds of police marching in formation from Millbank, with protesters later dragged away.

Javid issued his threats despite the peaceful tactics of protesters who have occupied public spaces including Parliament Square, Piccadilly Circus, Waterloo Bridge, Oxford Circus and Marble Arch. While hundreds have been arrested, just 10 people have so far been charged with any offence.

After widely publicised protests in London yesterday, the Metropolitan Police confirmed that 106 arrests were made. At Oxford Circus, actress Emma Thompson addressed demonstrators from a pink wooden boat in the middle of the road. “We are here in this little island of sanity and it makes me so happy to be able to join you all and to add my voice to the young people here who have inspired a whole new movement,” she said. Rings of police surrounded the boat before moving in to make arrests.

On Thursday evening, London Metropolitan Police issued a statement confirming more than 1,000 police had been mobilised and restating that under Section 14 orders, protests at Waterloo Bridge, Oxford Circus and Parliament Square were “illegal.” The statement followed a meeting between Javid and Met Chief Cressida Dick.

The Met responded to demands by Javid and others for tougher police action by explaining they were operating within legal constraints and with resources stretched to breaking point: “We have been asked why we are not using tactics such as containment—physically and forcibly stopping the protesters from moving around. The simple answer is we have no legal basis to do so. These are peaceful protesters; while disruptive their actions are not violent towards police, themselves or other members of the public.”

The media responded with demands for stepped-up repression, as urged by Javid.

On Thursday, Sky News presenter Adam Boulton attacked protesters for “fascistic disruption” in a clear attempt to redefine and criminalise the right to protest.

Boulton was articulating the stance of large sections of the media and political establishment. On Wednesday night, the Daily Mail carried a comment written by former Labour Home Secretary, now Sir David Blunkett. He railed, “Why hasn’t the full force of the law been used against these eco-anarchists who fill me with contempt?

“As Home Secretary between 2001 and 2004 I had to deal with the anti-globalisation protests and the Reclaim the Streets movement. I had to make decisions as to how far you allow these protests to go.”

Blunkett accurately described Labour’s draconian and anti-democratic response at the time: “What I learned was that you had to be tough. The full force of the law needs to be used against those who have been warned and yet who persist with their anti-social protests.”

On Thursday night, the Met warned that protests planned the following day at Heathrow Airport would be met with “firm action … We have requested mutual aid from other police forces to support our operation.”

The next morning dozens of police lined the streets around Heathrow Airport and surrounded a small group of protesters from Extinction Rebellion Youth. The 10 teenagers occupied a traffic island and did not impede entry to the airport. They held a banner that read, “Are we the last generation?”

Samar Faraj, 14, told reporters, “In 30 years’ time, I don’t want to be looking back on this and regretting not doing everything I could do to help prevent the disasters we’re facing.” Her fellow-protester Nathan Hunter, 15, said, “I’m protesting today because I don’t want to wake up in 15 years and regret that I didn’t do more to stop the climate crisis. I don’t want to live in a future defined by an unstable climate; A world where future generations may not be able to live happy, healthy lives—or even have lives at all.”

This week’s protests were organised by Extinction Rebellion (XR), attracting support from students and disparate sections of the middle-class, including retirees and professionals. An XR protest outside oil giant Shell’s corporate headquarters was joined by leading environmental lawyer Farhana Yamin, who helped draft the Paris Climate Agreement in 2015. Yamin superglued herself to the footpath outside Shell, telling reporters, “the legal process is pretty broken right now. And we’re having to break law rather than make law, because of the inaction of 30 years now of these companies.”

A press release issued by XR explained that their members had deliberately caused more than £6,000 of damage to Shell property to ensure their case is heard by a Crown Court jury (rather than a magistrate), where they hope to publicise their concerns over the activities of Shell.

XR’s protest actions, including blocking roads and light rail networks, are based on appeals to the capitalist state. XR is calling on the government to declare a climate emergency, reduce greenhouse gas emissions to net zero by 2025, and create a Citizens’ Assembly on ecological justice. XR explains such an assembly would comprise “randomly selected” members of the public who would supposedly “work together” on a “non-partisan basis” to solve the climate emergency.

While most climate change protesters arrested this week were released under investigation and without charge, the Met confirmed Thursday that they would “be brought back to be formally interviewed and charged as appropriate in due course.”

The statements by Sajid Javid, Blunkett and the vitriolic media attacks are a foretaste of how the state will respond to any movement in the working class. The arguments being deployed to justify police repression—including “disruption” and “inconvenience” to the public—will be used tomorrow to demand mass arrests and repression against striking railway workers, bus drivers, pilots and cabin crew, or NHS staff.

Monday, April 22, 2019: Over a thousand Extinction Rebellion protesters arrested in past week. Environmentalists stage a ‘die-in’ at the Natural History Museum while others consider whether to continue direct action: here.

UK: Defence minister’s sacking escalates Tory crisis amid rising UK/US tensions: here.