Monday, March 25, 2024

Your dog understands that some words “stand for” objects

CELL PRESS

Dog EEG — IMAGE:
THIS PHOTOGRAPH SHOWS A DOG EEG EXPERIMENTAL SETUP.
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CREDIT: GRZEGORZ ELIASIEWICZ

It’s no surprise that your dog can learn to sit when you say “sit” and come when called. But a study appearing March 22 in the journal Current Biology has made the unexpected discovery that dogs generally also know that certain words “stand for” certain objects. When dogs hear those words, brain activity recordings suggest they activate a matching mental representation in their minds.

“Dogs do not only react with a learned behavior to certain words,” says Marianna Boros (@FamDogProject) of the Department of Ethology at the Eötvös Loránd University, Budapest, Hungary, one of the paper’s co-first authors. “They also don’t just associate that word with an object based on temporal contiguity without really understanding the meaning of those words, but they activate a memory of an object when they hear its name.”

Word understanding tests with individuals who do not speak, such as infants and animals, usually require active choice, the researchers say. They’re asked to show or get an object after hearing its name. Very few dogs do well on such tests in the lab, often fetching objects correctly at a rate expected by chance.

The researchers wanted to look closer at dogs’ implicit understanding of object words by measuring brain activity using non-invasive EEG without asking them to act. The idea was that this might offer a more sensitive measure of their understanding of language.

In their studies, they had 18 dog owners say words for toys their dogs knew and then present the objects to them. Sometimes they presented the matching toy, while other times they would present an object that didn’t match. For example, an owner would say, “Zara, look, the ball,” and present the object while the dog’s brain activity was captured on EEG.

The brain recording results showed a different pattern in the brain when the dogs were shown a matching object versus a mismatched one. That’s similar to what researchers have seen in humans and is widely accepted as evidence that they understand the words. The researchers also found a greater difference in those patterns for words that dogs knew better, offering further support for their understanding of object words. Interestingly, while the researchers thought this ability might depend on having a large vocabulary of object words, their findings showed that it doesn’t.

“Because typical dogs learn instruction words rather than object names, and there are only a handful of dogs with a large vocabulary of object words, we expected that dogs’ capacity for referential understanding of object words will be linked to the number of object words they know; but it wasn’t,” says Lilla Magyari, also of Eötvös Loránd University and University of Stavanger and the other co-first author.

“It doesn’t matter how many object words a dog understands—known words activate mental representations anyway, suggesting that this ability is generally present in dogs and not just in some exceptional individuals who know the names of many objects,” Boros added.

The discovery that dogs as a species may generally have a capacity to understand words in a referential way, just as humans do, might reshape the way scientists think about the uniqueness of how humans use and understand language, the researchers say. That has important implications for theories and models of language evolution. For dog owners, it’s also an important realization.

“Your dog understands more than he or she shows signs of,” Magyari says. “Dogs are not merely learning a specific behavior to certain words, but they might actually understand the meaning of some individual words as humans do.”

The researchers are now curious to know if this ability to understand referential language is specific to dogs or might be present in other mammals as well. Either way, they want to learn more about how this ability emerged and whether it depends on dogs’ unique experience of living with people. They also want to know why, if dogs understand object words, more of them don’t show it.

###

Funding information can be found in the paper under acknowledgements. The authors declare no competing interests.

Current Biology, Boros and Magyari et al.: “Neural evidence for referential understanding of object words in dogs,” https://www.cell.com/current-biology/fulltext/S0960-9822(24)00171-4

Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit http://www.cell.com/current-biology. To receive Cell Press media alerts, contact press@cell.com.

JOURNAL

Current Biology

DOI

10.1016/j.cub.2024.02.029

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Neural evidence for referential understanding of object words in dogs

ARTICLE PUBLICATION DATE

22-Mar-2024

Your dog understands that some words ‘stand for’ objects, new study shows

It’s no surprise that dogs can learn to understand and respond to human words.

EÖTVÖS LORÁND UNIVERSITY

Dog during EEG — IMAGE:
IT’S NO SURPRISE THAT DOGS CAN LEARN TO UNDERSTAND AND RESPOND TO HUMAN WORDS. YOUR DOG CAN LEARN TO SIT WHEN YOU SAY “SIT” AND COME WHEN CALLED. BUT A NEW STUDY HAS MADE THE SURPRISING DISCOVERY BY RECORDING BRAIN ACTIVITY THAT DOGS GENERALLY ALSO KNOW THAT CERTAIN WORDS “STAND FOR” CERTAIN OBJECTS. WHEN THEY HEAR THOSE WORDS, THEY ACTIVATE A MATCHING MENTAL REPRESENTATION IN THEIR MINDS. THE FINDINGS ARE REPORTED IN *CURRENT BIOLOGY* ON MARCH 22, 2024.
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CREDIT: PHOTO: GRZEGORZELIASIEWICZ

It’s no surprise that dogs can learn to understand and respond to human words. Your dog can learn to sit when you say “sit” and come when called. But a new study has made the surprising discovery by recording brain activity that dogs generally also know that certain words “stand for” certain objects. When they hear those words, they activate a matching mental representation in their minds.

“Dogs do not only react with a learned behavior to certain words,” says Marianna Boros of the Department of Ethology at the Eötvös Loránd University, Budapest, Hungary. “They also don’t just associate that word with an object based on temporal contiguity without really understanding the meaning of those words, but they activate a memory of an object when they hear its name.”

Word understanding tests with individuals who do not speak, such as infants and animals, usually require active choice, the researchers explained. They’re asked to show or get an object after hearing its name. Very few dogs do well on such tests in the lab, often fetching objects correctly at a rate expected by chance.

In the new study, the researchers wanted to look closer at dogs’ implicit understanding of object words by measuring brain activity using non-invasive EEG. The idea was that this might offer a more sensitive measure of their understanding of language.

They had 18 dog owners say words for toys their dogs knew and then present the objects to them. Sometimes they presented the matching toy while other times they would present an object that didn’t match. For example, an owner would say, “Zara, look, the ball,” and presented the object while the dog’s brain activity was captured on EEG.

The brain recording results showed a different pattern in the brain when the dogs were shown a matching object versus a mismatched one, similarly to what we see in humans, and what is widely accepted as evidence that they understand the words. The researchers also found a greater difference in those patterns for words that dogs knew better, offering further support for their understanding of object words. While the researchers thought this ability might depend on having a large vocabulary of object words, their findings showed that it doesn’t.

“Because typical dogs learn instruction words rather than object names, and there are only a handful of dogs with a large vocabulary of object words, we expected that dogs’ capacity for referential understanding of object words will be linked to the number of object words they know; but it wasn’t,” said Lilla Magyari, also of Eötvös Loránd University and University of Stavanger.

“It doesn’t matter how many object words a dog understands, known words activate mental representations anyway, suggesting that this ability is generally present in dogs and not just in some exceptional individuals who know the names of many objects,” Boros added.

The discovery that dogs as a species generally may have a capacity to understand words in a referential way, just as humans do, might reshape the way scientists think about the uniqueness of how humans use and understand language, the researchers say. That has important implications for theories and models of language evolution. For dog owners, it’s an important realization also.

The researchers are now curious to know if this ability to understand referential language is specific to dogs or might be present in other mammals as well. Either way, they’re curious how this ability emerged and whether it depends on dogs’ unique experience of living with people. They also want to know why, if dogs understand object words, more of them don’t show it.

JOURNAL

Current Biology

DOI

10.1016/j.cub.2024.02.029.

ARTICLE TITLE

Neural evidence for referential understanding of object words in dogs

ARTICLE PUBLICATION DATE

22-Mar-2024

Experimental setup

EÖTVÖS LORÁND UNIVERSITY

Stem cell model offers first glimpse of early human development

ROCKEFELLER UNIVERSITY

Blastoid — IMAGE:
A BLASTOID, A STEM CELL MODEL SYSTEM THAT ALLOWS SCIENTISTS TO STUDY THE NUANCES OF HUMAN GASTRULATION.
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CREDIT: LABORATORY OF STEM CELL BIOLOGY AND MOLECULAR EMBRYOLOGY AT THE ROCKEFELLER UNIVERSITY

It’s one of life’s most defining moments—that crucial step in embryonic development, when an indistinct ball of cells rearranges itself into the orderly three-layered structure that sets the stage for all to come. Known as gastrulation, this crucial process unfolds in the third week of human development. “Gastrulation is the origin of our own individualization, the emergence of our axis,” says Rockefeller’s Ali Brivanlou. “It is the first moment that separates our heads from our behinds.”

Observing the molecular underpinnings of this pivotal event would go a long way toward helping scientists prevent miscarriages and developmental disorders. But studying human gastrulation has proven both technologically difficult and ethically complicated, and thus current approaches have had limited success in expanding our understanding of early human development. Now Brivanlou and colleagues have demonstrated how a stem cell model system known as a blastoid can allow the study of the nuances of human gastrulation in the presence of pre-implantation extra-embryonic cell types. Their study, published in Stem Cell Reports, describes the scientific and clinical potential of this new platform.

“Gastrulation was a tremendous black box. We had never seen ourselves at that stage,” Brivanlou says. “This moves us closer to understanding how we begin.”

A better blastocyst

Prior to implantation, an embryo is a ball of about 250 cells organized as a blastocyst. This elusive ball of cells was difficult to study directly, so scientists developed blastoids—stem-cell-based blastocyst models. Blastoids can be cloned, experimentally manipulated, and programmed, allowing scientists to study identical blastoids over and over again.

The question was whether blastoids could gastrulate in vitro. Unlike a blastocyst in vivo, which rolls around in the uterus until it attaches to maternal tissue, blastoids were good at modeling the ball of cells from which life emerges, but it remained unclear whether this in vitro model could model later stages of human development. That is, until Brivanlou developed a platform to allow blastoids to attach in vitro, and thereby progress toward gastrulation.

“We were then able to see epiblast symmetry breaking, marked by BRA expression, for the first time with the high molecular resolution,” says Riccardo De Santis, a research associate in the Brivanlou lab and lead author on the study. “This allowed us to start asking more detailed questions about the earliest moments of life.”

With this unprecedented clarity, the team directly observed two key moments in gastrulation: the first epiblast symmetry-breaking event and the emergence of the molecular markers of the primitive streak and mesoderm upon in vitro attachment.

The primitive streak is a structure that marks the beginning of gastrulation and lays the foundation for the three primary layers of the embryo. One of those layers, the mesoderm, forms during gastrulation and gives rise to muscles, bones, and the circulatory system. The team discovered that, as early as seven days after attachment, they were already able to use molecular markers to detect the earliest signature of a nascent primitive streak and mesodermal cells.

To confirm their findings, the team also compared the blastoid results with data from in vitro attached human embryos and demonstrated that blastoids express the same genes in vitro that a regular embryo would at that stage in vivo, a strong demonstration of the power of blastoids as models for human embryonic development. Further highlighting the power of the lab’s in vitro attached blastoid system, the team then used it to demonstrate that pathways that regulate the rise of the primitive streak and mesoderm in vivo also regulate blastoids symmetry breaking in vitro—all with nothing but stem-cell-derived blastoid models.

Along the way, the team also demonstrated that gastrulation in vitro can begin at day 12, earlier than once thought. “This will change textbooks,” Brivanlou says. “We’ve contributed to redefining the molecular signature and timing of the onset of gastrulation upon in vitro attachment”.

Therapeutic possibilities

The results demonstrate that blastoids, when combined with the Brivanlou lab’s unique attachment platform, are now capable of conveying insights into early human development that have long been inaccessible. De Santis envisions a future in which blastoid-based research leads to advancements in diagnosing and treating developmental disorders, or offers insights into potential causes of early miscarriages during gastrulation.

“Many couples can’t have babies because the embryo doesn’t attach properly, and many miscarriages occur in the first few weeks of pregnancy,” De Santis explains. “We now have a model system that can help us understand the molecular mechanism that defines whether a pregnancy will be successful or not.” In the near future, De Santis hopes to combine this method with machine learning to help predict pregnancy outcomes and the trajectories of developmental disorders by observing how model blastoids built with particular genetic makeups fare in vitro.

“A better understanding of gastrulation—and the ability to study it with a reliable model system—impacts everything from survival of the fetus to autism to neurodegeneration.”

JOURNAL

Stem Cell Reports

DOI

10.1016/j.stemcr.2023.11.005

ARTICLE TITLE

The emergence of human gastrulation upon in vitro attachment

Researchers propose a new way to identify when babies become conscious

UNIVERSITY OF BIRMINGHAM

Academics are proposing a new and improved way to help researchers discover when consciousness emerges in human infancy.

When over the course of development do humans become conscious? When the seventeenth-century French philosopher René Descartes was asked about infant consciousness by his critics, he eventually suggested that infants might have thoughts, albeit ones that are simpler than those of adults. Hundreds of years later, the issue of when human beings become conscious is a question which remains a challenge for psychologists and philosophers alike.

But now, in response to a recent article in Trends in Cognitive Sciences, two academics from the University of Birmingham have suggested an improved way to help scientists and researchers identify when babies become conscious.

In a Letter to the Editor, also published in Trends in Cognitive Sciences, Dr Henry Taylor, Associate Professor of Philosophy, and Andrew Bremner, Professor of Developmental Psychology, have explored a new approach which is being proposed, that involves identifying markers of consciousness in adults, and then measuring when babies start to exhibit larger numbers of these in development.

Dr Taylor says: “For example, imagine that in adults, we know that a certain very specific behaviour, or a specific pattern of brain activation always comes along with consciousness. Then, if we can identify when this behaviour or brain activation arises in babies, we have good reason to think that this is when consciousness emerges in babies. Behaviours and brain activations like this are what we call ‘markers’ of consciousness.”

This kind of approach is desperately needed since babies (unlike adults) cannot tell you what they are conscious of. Professor Bremner said: “It is really hard to establish when babies become conscious. This is mostly because infants can’t report their experiences and, as most parents will know, can be rather uncooperative particularly when it comes to experimental tasks. As we can’t just ask babies when they become conscious, the best approach is to try to identify a broad range of markers of consciousness, which appear in early development and late development, and then group them together, this could help us identify when consciousness emerges.”

In the recent article the researchers (Prof. Tim Bayne and colleagues) suggested four specific markers of consciousness, some of which are present in the late stages of gestation, and others which are found in early infancy. Based on this, the study argues that consciousness emerges early (from the last prenatal trimester).

But Professor Bremner and Dr Taylor say that this ignores other markers of consciousness. Previous research has identified a separate cluster of markers. These include:

•   Pointing (bringing a social partner’s attention to an object and checking).
•   Intentional control (intentional means-end coordination of actions - e.g., pulling a support to retrieve a distal object).
•   Explicit memory (deferred imitation of actions).

Dr Taylor said: “One of the complicated issues is that it does not look like all the markers point to the same age for the emergence of consciousness. The ones mentioned by Bayne and colleagues suggest somewhere between the third trimester of pregnancy and early infancy, but other markers suggest the age might be around one year old. In fact, at the really extreme end, some markers only emerge at around 3-4 years. Because there are so many different markers of consciousness which appear in early and late development it is extremely hard to come to a conclusion.”

Professor Bremner concluded: “We propose that a broad approach to markers, including those that emerge in early and late stage, is needed. We also recommend that a range of developmental models of the onset of consciousness should be considered. For instance, it may be that some markers emerge in one cluster in early development, with others in a later cluster. As well as this there may be a continuous and gradual emergence of certain markers stretching over gestation and throughout early life.

“We think that by clustering this broad selection of markers, we may finally be able to answer the question which has given us pause for thought for thousands of years. But it’s important to bear in mind that the answer may not be a simple one!”Academics are proposing a new and improved way to help researchers discover when consciousness emerges in human infancy.

But now, in response to a recent article in Trends in Cognitive Sciences, two academics from the University of Birmingham have suggested an improved way to help scientists and researchers identify when babies become conscious.

In a Letter to the Editor, also published in Trends in Cognitive Sciences, Dr Henry Taylor, Associate Professor of Philosophy, and Andrew Bremner, Professor of Developmental Psychology, have explored a new approach which is being proposed, that involves identifying markers of consciousness in adults, and then measuring when babies start to exhibit larger numbers of these in development.

But Professor Bremner and Dr Taylor say that this ignores other markers of consciousness. Previous research has identified a separate cluster of markers. These include:

ENDS

An embargoed copy of the article is available on request.

For more information, please contact Ellie Hail, Communications Manager, University of Birmingham at e.hail@bham.ac.uk or alternatively on +44 (0)7966 311 409. You can also contact the Press Office out of hours on +44 (0)121 414 2772.

Notes to editors

The University of Birmingham is ranked amongst the world’s top 100 institutions. Its work brings people from across the world to Birmingham, including researchers, teachers and more than 8,000 international students from over 150 countries.

JOURNAL

Trends in Cognitive Sciences

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE PUBLICATION DATE

22-Mar-2024

Toronto researchers devise new way to find proteins for targeted treatment of disease

Method interrogates entire human proteome for effector proteins, which influence stability of other proteins via induced proximity

UNIVERSITY OF TORONTO

Mikko Taipale_1 — IMAGE:
PROFESSOR MIKKO TAIPALE
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CREDIT: UNIVERSITY OF TORONTO

Researchers at the University of Toronto and Sinai Health have created a new platform to identify proteins that can be co-opted to control the stability of other proteins — a new but largely unrealized approach to the treatment of disease.

The researchers developed a method to interrogate the entire human proteome for ‘effector’ proteins, which can influence the stability of other proteins via induced proximity. The study marks the first time researchers have searched for effector proteins on this scale, and has identified many new effectors that could be used therapeutically.

“We found more than 600 new effector proteins in 14,000 genes,” said Juline Poirson, first author on the study and visiting scientist at U of T’s Donnelly Centre for Cellular and Biomolecular Research. “Over 200 of the new effectors can efficiently degrade their target proteins, while about 400 effectors were capable of stabilizing, and thereby increasing the abundance of, an artificial target protein.”

The study, which involved researchers at Sinai Health’s Lunenfeld-Tanenbaum Research Institute, was published in the journal Nature.

“Targeting proteins through induced proximity is a new and promising area of biomedical research,” said Mikko Taipale, principal investigator on the study and an associate professor of molecular genetics at the Donnelly Centre and the Temerty Faculty of Medicine. “Not only did we find new effectors worth further investigation for drug discovery, we developed a synthetic platform that can be used to conduct unbiased, proteome-wide, induced-proximity screens to continue expanding the library of effector proteins.”

The effectors currently in use for targeted protein degradation and stabilization are E3 ubiquitin-ligases (E3s) and deubiquitinases (DUBs), respectively. E3 is an enzyme that transfers the ubiquitin molecule to the target protein, which essentially flags the protein for a proteosome to digest it. On the other hand, a DUB enzyme removes the ubiquitin tag from a protein, thereby preventing the protein from being recognized and degraded by a proteosome.

The results of the study demonstrate that E3s are quite varied in the degree to which they can degrade target proteins they are brought into contact with. The research team even discovered four of what they call ‘angry E3s,’ which consistently degrade targets regardless of other factors, such as the location of the target within the cell.

A particularly surprising finding was that some of the strongest effectors for targeted protein degradation were E2 conjugating enzymes, instead of E3s. These differ from E3s in that they are involved at an earlier step of protein degradation and do not directly engage the target protein. Because E2s were not considered to be easily druggable, they had not been harnessed for targeted protein degradation until recently. They represent, however, the untapped potential of stronger effectors than ones currently in use.

The study shows that exploring the whole proteome for induced proximity offers enormous opportunities for therapeutic interventions. KLHL40, one of the identified effectors, could potentially be hijacked for targeted protein stabilization to treat skeletal muscle disorders. The research team also found that targeted protein degradation with FBXL12 and FBXL15 effectors could be particularly useful in treating chronic myeloid leukemia.

Targeted protein degradation and stabilization are innovative methods of drug discovery that have thus far been plagued with the “protein pair problem,” where the best effector for a target protein cannot be predicted accurately. Matching a target protein with the right effector is essential to successfully, and safely, facilitate degradation and stabilization processes in tissues.

“The synthetic screening platform developed by our team solves the protein matching issue through rapid, large-scale testing of effector and target protein interactions,” said Poirson. “We’re confident that an unbiased induced-proximity approach can be used to find effectors for almost any target.”

Visiting scientist Juline Poirson

CREDIT

University of Toronto

JOURNAL

Nature

DOI

10.1038/s41586-024-07224-3

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Proteome-scale discovery of protein degradation and stabilization effectors

ARTICLE PUBLICATION DATE

22-Mar-2024

COI STATEMENT

M.T. is a co-founder of Induxion Therapeutics. The University of Toronto has filed a patent application (pending; PCT/CA2023/050511) related to proteome-scale induced proximity screens. M.T., J.P., A.D., N.A. and L.M. are listed as co-inventors. The other authors declare no competing interests.

Researchers invent artificial intelligence model to design new superbug-fighting antibiotics

MCMASTER UNIVERSITY

Jon Stokes — IMAGE:
MCMASTER UNIVERSITY'S JONATHAN STOKES IS ONE OF THE RESEARCHERS WHO DEVELOPED A NEW GENERATIVE AI MODEL WHICH CAN DESIGN NEW ANTIBIOTICS TO STOP THE SPREAD OF ONE OF THE WORLD’S MOST DANGEROUS ANTIBIOTIC-RESISTANT BACTERIA.
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CREDIT: MCMASTER UNIVERSITY

Hamilton, ON, Mar. 22, 2024 – Researchers at McMaster University and Stanford University have invented a new generative artificial intelligence model which can design billions of new antibiotic molecules that are inexpensive and easy to build in the laboratory.

The worldwide spread of drug-resistant bacteria has created an urgent need for new antibiotics, but even modern AI methods are limited at isolating promising chemical compounds, especially when researchers must also find ways to manufacture these new AI-guided drugs and test them in the lab.

In a new study, published today in the journal Nature Machine Intelligence, researchers report they have developed a new generative AI model called SyntheMol, which can design new antibiotics to stop the spread of Acinetobacter baumannii, which the World Health Organization has identified as one of the world’s most dangerous antibiotic-resistant bacteria.

Notoriously difficult to eradicate, A. baumannii can cause pneumonia, meningitis and infect wounds, all of which can lead to death. Researchers say few treatment options remain.

“Antibiotics are a unique medicine. As soon as we begin to employ them in the clinic, we're starting a timer before the drugs become ineffective, because bacteria evolve quickly to resist them,” says Jonathan Stokes, lead author on the paper and an assistant professor in McMaster’s Department of Biomedicine & Biochemistry, who conducted the work with James Zou, an associate professor of biomedical data science at Stanford University.

“We need a robust pipeline of antibiotics and we need to discover them quickly and inexpensively. That's where the artificial intelligence plays a crucial role,” he says.

Researchers developed the generative model to access tens of billions of promising molecules quickly and cheaply.

They drew from a library of 132,000 molecular fragments, which fit together like Lego pieces but are all very different in nature. They then cross-referenced these molecular fragments with a set of 13 chemical reactions, enabling them to identify 30 billion two-way combinations of fragments to design new molecules with the most promising antibacterial properties.

Each of the molecules designed by this model was in turn fed through another AI model trained to predict toxicity. The process yielded six molecules which display potent antibacterial activity against A. baumannii and are also non-toxic.

"Synthemol not only designs novel molecules that are promising drug candidates, but it also generates the recipe for how to make each new molecule. Generating such recipes is a new approach and a game changer because chemists do not know how to make AI-designed molecules,” says Zou, who co-authored the paper.

The research is funded in part by the Weston Family Foundation, the Canadian Institutes of Health Research, and Marnix and Mary Heersink.

-30-

JOURNAL

Nature Machine Intelligence

DOI

10.1038/s42256-024-00809-7

ARTICLE PUBLICATION DATE

22-Mar-2024

SFU Publishing Director Hannah McGregor's new book asks "Can podcasting save academia?"

SIMON FRASER UNIVERSITY

A new book from Lori Beckstead, Ian M. Cook, and SFU Publishing Director Hannah McGregor, explores how the growth of scholarly podcasting may engender radical possibilities for how we conceive of knowledge creation and peer review, and the transformative potential of new modes of creating and reviewing expert knowledge.

"Podcast Or Perish" investigates the historical development of the norms of scholarly communication and asks how podcasting might change how we think about scholarly work. Could this be the call to action academia needs?

Read on and find out!

Research uncovers a rare resin fossil find: A spider that aspires to be an ant

OREGON STATE UNIVERSITY

Myrmarachne colombiana — IMAGE:
MYRMARACHNE COLOMBIANA
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CREDIT: GEORGE POINAR JR.

CORVALLIS, Ore. – Arachnophobia can make humans flee at the sight of a brown recluse, black widow or even a daddy long legs, but animal predators of spiders know no such fear.

That’s why, paleobiologist George Poinar Jr. explains, some spider species have developed the defense of deception. They masquerade as a much less desirable prey – ants – and Poinar’s recent paper in Historical Biology presents an early record of an ant-mimicking spider in fossilized resin.

“Ants are particularly good creatures for spiders to pretend to be – many animals find ants distasteful or dangerous to eat,” said Poinar, who has a courtesy appointment in the Oregon State University College of Science. “Ants are aggressive in their own defense – they have a strong bite as well as a stinging venom, and they can call in dozens of nestmates as allies. Spiders, meanwhile, have no chemical defenses and are loners, which makes them vulnerable to being hunted by larger spiders, wasps and birds – predators that would rather avoid ants. So if a spider can be like an ant, it’s more likely to be unbothered.”

Spiders that disguise themselves as ants live in many locations around the globe but until now most had been able to avoid detection from fossil researchers as well as predators. The specimen that Poinar describes, which he named Myrmarachne colombiana, was entombed in a type of fossilized resin known as copal.

Copal is a less mature form of fossilized resin than amber, which is routinely dated to be 25 million or more years old. Still, copal can be up to 3 million years old.

The age of the resin in this case, however, could not be determined, said Poinar, an international expert in using plant and animal life forms preserved in amber to learn about the biology and ecology of the distant past.

The resin block he was working with, which came from Medellin, Colombia, was too small to age-test without risk of damaging the spider inside. Poinar notes there is no record of any currently living ant-mimicking spider making its home in Colombia.

“It is a challenge for spiders to accomplish this magical transformation to ants,” he said. “Ants have six legs and two long antennae, while spiders have eight legs and no antennae.”

To get around those anatomical differences, Poinar said, spiders typically position their two front legs in a way that approximates the look of antennae. But number of legs and absence/presence of antennae are not the only characteristics differentiating an ant’s appearance from a spider’s.

“The abdomen and cephalothorax of spiders are closely attached, while in ants the equivalent of these body parts are separated by a narrow segment called the petiole,” Poinar said. “And there are many other lesser structures that need to be modified in spiders for them to closely resemble ants. How is this accomplished? Most scientists say it begins with spider mutation, adaptation and then natural selection.

“However, I think there is some spider reasoning and intelligence involved too since the spiders often model their body changes after specific ants in the same environment,” he said. “In the early days, we were told that all habits of insects were the result of instincts, but that is no longer the case.”

Several groups of spiders have developed the ability to look and behave like various types of ants, he added. There are also spiders that try to blend in as other insects, such as flies, beetles and wasps.

Most of the copycat spiders belong to a few families of hunting spiders, including Salticidae or jumping spiders. The specimen in the Colombian copal appears to be a jumping spider.

Spiders that practice mimicry also come from the Corinnidae (sun spider), Thomisidae (flower spider) and Zodariidae (spotted or ant spider) families.

JOURNAL

Historical Biology

DOI

10.1080/08912963.2024.2320190

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Myrmarachne colombiana sp. n. (Araneae: Salticidae), a new species of ant-mimic spider in copal from Colombia, South America