It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Scientists decode when and how kissing evolved in humans
Vishwam Sankaran Mon 28 October 2024 Babylonian clay model showing couple on couch engaged in sex and kissing (The Trustees of the British Museum)
Kissing in humans evolved as a symbolic expression of love from grooming behaviours seen in ancestral great apes, a comprehensive new study says.
The kiss has been a versatile way by which humans across civilisations and societies have shown affection, intimacy, or social bonding, most often in a way that is regulated by cultural conventions.
A study published last year points to Mesopotamia around 4,500 years ago as one of the earliest known places where kissing was a “well-established practice”.
Thousands of clay tablets recovered from early human cultures that lived between the Euphrates and Tigris rivers in modern-day Iraq and Syria reveal that kissing was considered a part of romantic intimacy during these times.
However, how exactly our species began communicating affection this way remains a topic of debate.
One theory suggests kissing evolved from nurturing care behaviors like premastication in which caregivers feed infants with pre-chewed food.
Another relates the act to have evolved as a kind of compatibility test in which potential mates tasted and sampled each other orally to determine health.
In the new study, published in the journal Evolutionary Anthropology, scientists conducted a comprehensive review of such existing hypotheses to explore the roots of this intimate behaviour in humans.
The analysis also looked at parallels in the animal world of behaviour similar in form and function to human kissing. Chimpanzees and bonobos use gestures to initiate and change positions during grooming (University of St Andrews)
Researchers noticed that the final act of grooming in our hairy ape ancestors involves protruding lips and slight suction to remove debris or parasites.
While humans evolved to have less body hair, this final act that scientists call the “groomer’s final kiss” may have remained without its hygienic relevance as a “vestigial action”, scientists say.
This act involving protruding lips and suction mirrors the context and function of modern human kissing, they say. Orangutan baby “Changi” kisses his mother “Lea” on 24 January 2012 (DPA/AFP via Getty Images)
“Great ape social behaviour suggests that kissing is likely the conserved final mouth-contact stage of a grooming bout when the groomer sucks with protruded lips the fur or skin of the groomed to latch on debris or a parasite,” researchers write.
“What was once a time- and labour-intensive ritual to cement and strengthen close social ties became gradually compressed until a groomer’s final kiss turned into a crystalised symbol of trust and affiliation,” they say.
With this theory, scientists speculate kissing was established among human ape ancestors as they started spending considerable time on the ground away from trees.
This could have come “only after” ancient climate change shifted ecology from forested habitats toward drier and more open landscapes, researchers say.
Thursday, October 10, 2024
Indonesia biomass drive threatens key forests: report
Jakarta (AFP) – Indonesia's push to add wood-burning to its energy mix and exports is driving deforestation, including in key habitats for endangered species such as orangutans, a report said Thursday.
Issued on: 10/10/2024 -
A Sumatran orangutan, one of the species at risk from deforestation according to the new report
Bioenergy, which uses organic material like trees to produce power, is considered renewable by the International Energy Agency as carbon released by burning biomass can theoretically be absorbed by planting more trees.
But critics say biomass power plants emit more carbon dioxide per unit of energy produced than modern coal plants, and warn that using biomass to "co-fire" coal plants is just a way to extend the life of the polluting fossil fuel.
Producing the wood pellets and chips used for "co-fire" coal plants also risks driving deforestation, with natural forests cut down and replaced by quick-growing monocultures.
That, according to a report produced by a group of Indonesian and regional NGOs, is exactly what is happening in Indonesia, home to the world's third-largest rainforest area.
"The country's forests face unprecedented threats from the industrial scale projected for biomass demand," said the groups, which include Auriga Nusantara and Earth Insight.
Indonesia's production of wood pellets alone jumped from 20,000 to 330,000 tonnes from 2012 to 2021, the report said.
Auriga Nusantara estimates nearly 10,000 hectares of deforestation has been caused by biomass production in the last four years. Forests for 'human survival'
But the report warns that much more is at risk as Indonesia ramps up biomass, particularly in its coal-fired power plants.
The report looked at existing co-firing plants and pulp mills around Indonesia and the 100 kilometres (62 miles) surrounding each.
They estimate more than 10 million hectares of "undisturbed forest" lie within these areas and are at risk of deforestation, many of which "significantly overlap" with the habitat of endangered species.
Animals at risk include orangutans in Sumatra and Borneo, the report said.
Using wood to achieve just a 10 percent reduction in coal at Indonesia's largest power plants "could trigger the deforestation of an area roughly 35 times the size of Jakarta," the report warned.
Indonesia's environment and forestry ministry officials did not immediately respond to AFP's request for comment.
Indonesia saw a 27 percent jump in primary forest loss last year after a downward trend from a peak in 2015-2016, according to the World Resources Institute.
The groups also point the finger at growing demand in South Korea and Japan, two major export destinations for Indonesia's wood pellets.
They urged Indonesia to commit to protecting its remaining natural forest and reform its energy plans to focus on solar, while banning new coal projects.
Japan and South Korea should end biomass incentives and focus on cleaner renewable options, the group urged.
"There are no math tricks that can justify burning forests for energy," the NGOs said.
"Science has clearly proven the vital role of tropical forests for climate stability, biodiversity and human survival."
Geosmin is a volatile compound of microbial origin with a distinct “earthy” to “musty” odor that can affect the quality of water and food. A research team led by Dietmar Krautwurst from the Leibniz Institute for Food Systems Biology at the Technical University of Munich has now identified and characterized the human odorant receptor for geosmin for the first time.
Geosmin is responsible for the typical odor that occurs when rain falls on dry soil. This odorant is produced by microorganisms in the soil and is also found in plants such as cactus flowers and red beet.
Many creatures react very sensitively to geosmin, whereby the odorant can have a repellent or attractive effect. For example, it warns fruit flies of spoiled food. Camels, on the other hand, are attracted to water-rich areas. “This shows that geosmin acts as a chemical signaling substance in the animal kingdom and certainly also in humans,” explains first author Lena Ball from the Leibniz Institute.
Geosmin can impair food quality
"While the smell of geosmin suits red beet, its presence in foods such as fish, beans, cocoa, water, wine or grape juice is problematic. In these, it greatly impairs sensory quality and acceptance,” explains Stephanie Frank, food chemist at the Leibniz Institute. Even low concentrations of 4 to 10 ng/L are sufficient for a person to perceive the odor in water. This corresponds to about one teaspoon of geosmin in the water volume of 200 Olympic swimming pools.
Although geosmin has been known since 1965 and is important for food production, it was previously unknown which odorant receptor humans use to perceive geosmin. The team headed by principal investigator Dietmar Krautwurst has now carried out a bidirectional receptor screening and identified and functionally characterized the corresponding receptor for the first time.
Only one human odorant receptor for geosmin
Of 616 human olfactory receptor variants tested, only the OR11A1 receptor responded to physiologically relevant concentrations of the odorant. The team also investigated whether the identified receptor reacts to other food-relevant odorants. Of the 177 substances tested, only the earthy-smelling 2-ethylfenchol was able to significantly activate the receptor. This compound, is also of microbial origin.
"As geosmin is an important signaling substance in the animal kingdom, we also investigated how the odorant receptors of the kangaroo rat, mouse, rhesus monkey, Sumatran orangutan, polar bear and camel, which are genetically most closely related to the human receptor, react to geosmin. We wanted to find out whether the highly selective recognition of geosmin by the same receptor has been preserved over 100 million years of mammalian evolution,” reports doctoral student Lena Ball. As the team's comparative studies show, the human receptor, together with the monkey receptors, is one of the less sensitive sensors. In the experiment, the kangaroo rat's odorant receptor reacted around 100 times more sensitively to geosmin than the human receptor.
"The new findings on the highly sensitive odorant receptors of some animals once again emphasize the biological relevance of geosmin as a signaling substance. They could also help to develop novel detection systems that can be used to monitor food quality during production and storage or to control the water quality of freshwater reservoirs,” concludes Dietmar Krautwurst.
Publication: Ball, L., Frey, T., Haag, F., Frank, S., Hoffmann, S., Laska, M., Steinhaus, M., Neuhaus, K., and Krautwurst, D. (2024). Geosmin, a Food- and Water-Deteriorating Sesquiterpenoid and Ambivalent Semiochemical, Activates Evolutionary Conserved Receptor OR11A1. J Agric Food Chem. 10.1021/acs.jafc.4c01515. pubs.acs.org/doi/epdf/10.1021/acs.jafc.4c01515
More Information
Human odorant receptors
Humans possess a total of around 400 different odorant receptor genes, which in turn encode around 600 different allelic receptor variants in the nasal mucosa. The latter are responsible for the perception and differentiation of various odors. However, there is still a need for research to determine the exact number and function of all receptor variants. At present, it is only known for around 20 percent of human odorant receptors which odorants they can detect.
Test system used for screening
According to Dietmar Krautwurst, the cellular test system developed by the Leibniz researchers and used for receptor screening is unique in the world. He and his team have genetically modified the test cells so that they act like small biosensors for odorous substances. The researchers determine exactly which odorant receptor variant the test cells present on their surface. In this way, the researchers can specifically investigate which receptor reacts how strongly to which odorant. The Leibniz Institute has extensive collections of odorants and receptors, which it uses for its research work.
Information About the Institute:
The Leibniz Institute for Food Systems Biology at the Technical University of Munich (Leibniz-LSB@TUM) comprises a new, unique research profile at the interface of Food Chemistry & Biology, Chemosensors & Technology, and Bioinformatics & Machine Learning. As this profile has grown far beyond the previous core discipline of classical food chemistry, the institute spearheads the development of a food systems biology. Its aim is to develop new approaches for the sustainable production of sufficient quantities of food whose biologically active effector molecule profiles are geared to health and nutritional needs, but also to the sensory preferences of consumers. To do so, the institute explores the complex networks of sensorically relevant effector molecules along the entire food production chain with a focus on making their effects systemically understandable and predictable in the long term.
The Leibniz-LSB@TUM is a member of the Leibniz Association, which connects 96 independent research institutions. Their orientation ranges from the natural sciences, engineering and environmental sciences through economics, spatial and social sciences to the humanities. Leibniz Institutes address issues of social, economic and ecological relevance.They conduct basic and applied research, including in the interdisciplinary Leibniz Research Alliances, maintain scientific infrastructure, and provide research-based services. The Leibniz Association identifies focus areas for knowledge transfer, particularly with the Leibniz research museums. It advises and informs policymakers, science, industry and the general public.
Leibniz institutions collaborate intensively with universities – including in the form of Leibniz ScienceCampi – as well as with industry and other partners at home and abroad. They are subject to a transparent, independent evaluation procedure. Because of their importance for the country as a whole, the Leibniz Association Institutes are funded jointly by Germany’s central and regional governments. The Leibniz Institutes employ around 21,300 people, including 12,200 researchers. The financial volume amounts to 2,2 billion euros.
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By Maddie Molloy, BBC Climate & Science Dr Lauren Brent As a result of hurricane impacts, macaque monkeys are getting along better with other monkeys in their social groups
Macaque monkeys got on better with others in their social groups after a devastating hurricane, according to researchers.
Researchers studied the impacts of a hurricane on a population of Rhesus macaques on an island off Puerto Rico.
Temperatures are often around 40C so shade is a precious resource for macaques, since tree cover is still far below pre-hurricane levels.
Macaques, who are known for being aggressive and competitive, have become more tolerant of one another to get access to scarce shade.
In 2017 Hurricane Maria hit Puerto Rico, killing more than 3,000 people and destroying 63% of the vegetation on Cayo Santiago.
The island is also known as Monkey Island and is home to the macaques studied by the researchers.
The study, which was led by the universities of Pennsylvania and Exeter and published in the journal Science, found that storm damage changed the evolutionary benefits of sharing shade and tolerating others.
"We expected that after the disaster in a more competitive landscape with less shade resources, you would have perhaps more aggression. But actually, that's really not what we found. We found the opposite pattern," said Dr Testard.
Using data collected before and after the hurricane, the researchers examined the strength and number of social ties among macaques.
Whether it's food or shade, macaques aren't known for being very good at sharing resources.
Due to the increased tolerance, more macaques were able to access scarce shade, which is crucial to their survival.
"There's still competition within your groups the way it was before, but the rules of the game have changed since then. What really seems to be important, are the risks of not living, heat, stress and getting access to shade," said Professor Lauren Brent, from the University of Exeter.
Researchers found that the macaques' increased tolerance spilled over into other aspects of their daily lives.
Macaques that had been sharing shade were also spending time together in the mornings, before the heat forced them to seek shade.
In effect, the hurricane changed the rules of the game in the monkeys’ society.
A goat with an arrow wound nibbles the medicinal herb dittany. O. Dapper, CC BY
When a wild orangutan in Sumatra recently suffered a facial wound, apparently after fighting with another male, he did something that caught the attention of the scientists observing him.
The animal chewed the leaves of a liana vine – a plant not normally eaten by apes. Over several days, the orangutan carefully applied the juice to its wound, then covered it with a paste of chewed-up liana. The wound healed with only a faint scar. The tropical plant he selected has antibacterial and antioxidant properties and is known to alleviate pain, fever, bleeding and inflammation.
The striking story was picked up by media worldwide. In interviews and in their research paper, the scientists stated that this is “the first systematically documented case of active wound treatment by a wild animal” with a biologically active plant. The discovery will “provide new insights into the origins of human wound care.”
To me, the behavior of the orangutan sounded familiar. As a historian of ancient science who investigates what Greeks and Romans knew about plants and animals, I was reminded of similar cases reported by Aristotle, Pliny the Elder, Aelian and other naturalists from antiquity. A remarkable body of accounts from ancient to medieval times describes self-medication by many different animals. The animals used plants to treat illness, repel parasites, neutralize poisons and heal wounds.
The term zoopharmacognosy – “animal medicine knowledge” – was invented in 1987. But as the Roman natural historian Pliny pointed out 2,000 years ago, many animals have made medical discoveries useful for humans. Indeed, a large number of medicinal plants used in modern drugs were first discovered by Indigenous peoples and past cultures who observed animals employing plants and emulated them.
What you can learn by watching animals
Some of the earliest written examples of animal self-medication appear in Aristotle’s “History of Animals” from the fourth century BCE, such as the well-known habit of dogs to eat grass when ill, probably for purging and deworming.
Aristotle also noted that after hibernation, bears seek wild garlic as their first food. It is rich in vitamin C, iron and magnesium, healthful nutrients after a long winter’s nap. The Latin name reflects this folk belief: Allium ursinum translates to “bear lily,” and the common name in many other languages refers to bears.
Pliny explained how the use of dittany, also known as wild oregano, to treat arrow wounds arose from watching wounded stags grazing on the herb. Aristotle and Dioscorides credited wild goats with the discovery. Vergil, Cicero, Plutarch, Solinus, Celsus and Galen claimed that dittany has the ability to expel an arrowhead and close the wound. Among dittany’s many known phytochemical properties are antiseptic, anti-inflammatory and coagulating effects.
According to Pliny, deer also knew an antidote for toxic plants: wild artichokes. The leaves relieve nausea and stomach cramps and protect the liver. To cure themselves of spider bites, Pliny wrote, deer ate crabs washed up on the beach, and sick goats did the same. Notably, crab shells contain chitosan, which boosts the immune system.
When elephants accidentally swallowed chameleons hidden on green foliage, they ate olive leaves, a natural antibiotic to combat salmonella harbored by lizards. Pliny said ravens eat chameleons, but then ingest bay leaves to counter the lizards’ toxicity. Antibacterial bay leaves relieve diarrhea and gastrointestinal distress. Pliny noted that blackbirds, partridges, jays and pigeons also eat bay leaves for digestive problems.
Weasels were said to roll in the evergreen plant rue to counter wounds and snakebites. Fresh rue is toxic. Its medical value is unclear, but the dried plant is included in many traditional folk medicines. Swallows collect another toxic plant, celandine, to make a poultice for their chicks’ eyes. Snakes emerging from hibernation rub their eyes on fennel. Fennel bulbs contain compounds that promote tissue repair and immunity.
According to the naturalist Aelian, who lived in the third century BCE, the Egyptians traced much of their medical knowledge to the wisdom of animals. Aelian described elephants treating spear wounds with olive flowers and oil. He also mentioned storks, partridges and turtledoves crushing oregano leaves and applying the paste to wounds.
The study of animals’ remedies continued in the Middle Ages. An example from the 12th-century English compendium of animal lore, the Aberdeen Bestiary, tells of bears coating sores with mullein. Folk medicine prescribes this flowering plant to soothe pain and heal burns and wounds, thanks to its anti-inflammatory chemicals.
Ibn al-Durayhim’s 14th-century manuscript “The Usefulness of Animals” reported that swallows healed nestlings’ eyes with turmeric, another anti-inflammatory. He also noted that wild goats chew and apply sphagnum moss to wounds, just as the Sumatran orangutan did with liana. Sphagnum moss dressings neutralize bacteria and combat infection.
Nature’s pharmacopoeia
Of course, these premodern observations were folk knowledge, not formal science. But the stories reveal long-term observation and imitation of diverse animal species self-doctoring with bioactive plants. Just as traditional Indigenous ethnobotany is leading to lifesaving drugs today, scientific testing of the ancient and medieval claims could lead to discoveries of new therapeutic plants.
Animal self-medication has become a rapidly growing scientific discipline. Observers report observations of animals, from birds and rats to porcupines and chimpanzees, deliberately employing an impressive repertoire of medicinal substances. One surprising observation is that finches and sparrows collect cigarette butts. The nicotine kills mites in bird nests. Some veterinarians even allow ailing dogs, horses and other domestic animals to choose their own prescriptions by sniffing various botanical compounds.
Mysteries remain. No one knows how animals sense which plants cure sickness, heal wounds, repel parasites or otherwise promote health. Are they intentionally responding to particular health crises? And how is their knowledge transmitted? What we do know is that we humans have been learning healing secrets by watching animals self-medicate for millennia.
Dr Lauren Brent
