Science ahead of its time: Secret of 157-year old Darwin manuscript
Today is Evolution day – a day commemorating the publication of Charles Darwin’s Origin of Species on 24 November 1859. Darwin’s seminal work is now considered the most influential book of science in history and has inspired countless new disciplines. As recently found by the Darwin Online project at the National University of Singapore (NUS), the book has been translated into fifty languages, far more than any other scientific book.
Now on the 163rd anniversary of the publication of the Origin of Species, the Darwin Online project releases one of the most exceptional Darwin manuscripts still in private hands. It is also up for auction at Sotheby’s auction house in New York City, making international news, and likely to hit a record price of one million pounds. To understand this unique document, Sotheby’s consulted historian of science Dr John van Wyhe from the NUS Department of Biological Sciences, Fellow of Tembusu College at NUS, and founder and Director of Darwin Online. What was previously taken to be a page of the rough draft of Origin of Species turned out to be much more interesting.
Secret of 157-year old Darwin manuscript: Darwin’s hand-written quote from Origin of Species (left) for the Autographic Mirror magazine
The document is the result of an autograph hunter named Hermann Kindt who wrote to Darwin in 1865 to request for a written passage from Origin of Species and sign it. This was for Kindt’s magazine, Autographic Mirror, which published examples of the handwriting of famous people. Darwin wrote out a passage from the conclusion to the recent 1861 third 3rd edition of Origin of Species, p. 514:
“…It is no valid objection [to this theory of evolution] that science as yet throws no light on the far higher problem of the essence or origin of life. Who can explain what is the essence of the attraction of gravity? No one now objects to following out the results consequent on this unknown element of attraction; notwithstanding that Leibnitz formerly accused Newton of introducing ‘occult qualities and miracles into philosophy.'”
It was published in Kindt’s magazine which is also released today in Darwin Online.
As a passage from the Origin of Species in Darwin’s own handwriting, and with his rare full signature, this piece is quite unique. But why did Darwin choose this passage in particular from the 490 pages of the book? Dr van Wyhe has found the answer.
Shortly after the book was published, there were many objections to Darwin’s theory. Some thought that his ‘natural selection’ was not a real force in nature.
Just then, Darwin happened to read a biography of Isaac Newton in which one of Newton’s critics claimed that his law of gravity was not real but only imaginary “occult qualities and miracles” pushed into science. Darwin was struck by the parallel. His critics thought natural selection was an unreal cause. The day he finished the biography, Darwin wrote to a scientific colleague about it, saying he would use this example to answer critics in future. Almost immediately he had a chance to do so by adding a new passage to the next American printing of Origin of Species, using the quote about Newton. Later the passage appeared in the 3rd and all subsequent editions of the book.
So now it can be understood why Darwin chose this particular passage to copy out for Kindt in 1865 as he saw it as a powerful defence for his theory of evolution by natural selection. It was as if Darwin was saying, ‘they accused Newton’s law of gravity of being fake and now it is accepted by the whole world. It will be the same for the law of natural selection’. Darwin was right – his theory of evolution is now the foundation of all the life sciences.
This unique Darwin manuscript, transcribed with an introduction by Dr van Wyhe, is freely available only at Darwin Onlinehere.
Press release from the National University of Singapore
Webb Reveals an Exoplanet Atmosphere as Never Seen Before
The NASA/ESA/CSA James Webb Space Telescope just scored another first: a molecular and chemical profile of a distant world’s skies.
This image shows an artist’s impression of the planet WASP-39 b and its star. The planet has a fuzzy orange-blue atmosphere with hints of longitudinal cloud bands below. The left quarter of the planet (the side facing the star) is lit, while the rest is in shadow. The star is bright yellowish-white, with no clear features. Credit: NASA, ESA, CSA, J. Olmsted (STScI)
The NASA/ESA/CSA James Webb Space Telescope just scored another first: a molecular and chemical portrait of a distant world’s skies. While Webb and other space telescopes, including the NASA/ESA Hubble Space Telescope, have previously revealed isolated ingredients of this heated planet’s atmosphere, the new readings provide a full menu of atoms, molecules, and even signs of active chemistry and clouds. The latest data also give a hint of how these clouds might look up close: broken up rather than as a single, uniform blanket over the planet.
The telescope’s array of highly sensitive instruments was trained on the atmosphere of WASP-39 b, a “hot Saturn” (a planet about as massive as Saturn but in an orbit tighter than Mercury) orbiting a star some 700 light-years away. This Saturn-sized exoplanet was one of the first examined by the NASA/ESA/CSA James Webb Space Telescope when it began regular science operations. The results have excited the exoplanet science community. Webb’s exquisitely sensitive instruments have provided a profile of WASP-39 b’s atmospheric constituents and identified a plethora of contents, including water, sulphur dioxide, carbon monoxide, sodium and potassium.
Image Description: Graphic titled “Hot Gas Giant Exoplanet WASP-39 b Atmosphere Composition.” The graphic includes four graphs—transmission spectra—arranged in a 2 by 2 grid with an illustration of the planet and its star in the background. Credit: NASA, ESA, CSA, J. Olmsted (STScI)
This graph displays data from Webb’s NIRISS instrument, showing fingerprints of potassium (K), water (H2O), and carbon monoxide (CO). Credit: NASA, ESA, CSA, J. Olmsted (STScI)
This graph displays data from Webb’s NIRCam instrument, showing a prominent water signature. Credit: NASA, ESA, CSA, J. Olmsted (STScI)
This graph displays data from Webb’s NIRSpec instrument, indicating signatures of water, sulfur dioxide (SO2), carbon dioxide (CO2), and carbon monoxide (CO). Credit: NASA, ESA, CSA, J. Olmsted (STScI)
This graph displays data from Webb’s NIRSpec instrument, indicating signatures of potassium (K), water (H2O), carbon monoxide (CO), sulfur dioxide (SO2), carbon dioxide (CO2), and sodium (Na). Credit: NASA, ESA, CSA, J. Olmsted (STScI)
The findings bode well for the capability of Webb’s instruments to conduct the broad range of investigations of exoplanets — planets around other stars — hoped for by the science community. That includes probing the atmospheres of smaller, rocky planets like those in the TRAPPIST-1 system.
“We observed the exoplanet with several instruments that together cover a broad swath of the infrared spectrum and a panoply of chemical fingerprints inaccessible until JWST,” said Natalie Batalha, an astronomer at the University of California, Santa Cruz, who contributed to and helped coordinate the new research. “Data like these are a game changer.”
The suite of discoveries is detailed in a set of five new scientific papers, three of which are in press and two of which are under review. Among the unprecedented revelations is the first detection in an exoplanet atmosphere of sulphur dioxide, a molecule produced from chemical reactions triggered by high-energy light from the planet’s parent star. On Earth, the protective ozone layer in the upper atmosphere is created in a similar way.
“This is the first time we have seen concrete evidence of photochemistry — chemical reactions initiated by energetic stellar light — on exoplanets,” said Shang-Min Tsai, a researcher at the University of Oxford in the United Kingdom and lead author of the paper explaining the origin of sulphur dioxide in WASP-39 b’s atmosphere. “I see this as a really promising outlook for advancing our understanding of exoplanet atmospheres with [this mission].”
This led to another first: scientists applying computer models of photochemistry to data that require such physics to be fully explained. The resulting improvements in modelling will help build the technological know-how needed to interpret potential signs of habitability in the future.
“Planets are sculpted and transformed by orbiting within the radiation bath of the host star,” Batalha said. “On Earth, those transformations allow life to thrive.”
The planet’s proximity to its host star — eight times closer than Mercury is to our Sun — also makes it a laboratory for studying the effects of radiation from host stars on exoplanets. Better knowledge of the star-planet connection should bring a deeper understanding of how these processes affect the diversity of planets observed in the galaxy.
Other atmospheric constituents detected by the Webb telescope include sodium (Na), potassium (K), and water vapour (H2O), confirming previous space- and ground-based telescope observations as well as finding additional fingerprints of water, at these longer wavelengths, that haven’t been seen before.
Webb also saw carbon dioxide (CO2) at higher resolution, providing twice as much data as reported from its previous observations. Meanwhile, carbon monoxide (CO) was detected, but obvious signatures of both methane (CH4) and hydrogen sulphide (H2S) were absent from the Webb data. If present, these molecules occur at very low levels.
To capture this broad spectrum of WASP-39 b’s atmosphere, an international team numbering in the hundreds independently analysed data from four of the Webb telescope’s finely calibrated instrument modes.
“We had predicted what [the telescope] would show us, but it was more precise, more diverse and more beautiful than I think I actually believed it would be,” said Hannah Wakeford, an astrophysicist at the University of Bristol in the United Kingdom who investigates exoplanet atmospheres.
Having such a complete roster of chemical ingredients in an exoplanet atmosphere also gives scientists a glimpse of the abundance of different elements in relation to each other, such as the carbon-to-oxygen or potassium-to-oxygen ratios. That in turn provides insight into how this planet — and perhaps others — formed out of the disc of gas and dust surrounding the parent star in its younger years.
WASP-39 b’s chemical inventory suggests a history of smashups and mergers of smaller bodies called planetesimals to create an eventual goliath of a planet.
“The abundance of sulphur [relative to] hydrogen indicated that the planet presumably experienced significant accretion of planetesimals that can deliver [these ingredients] to the atmosphere,” said Kazumasa Ohno, a UC Santa Cruz exoplanet researcher who worked on Webb data. “The data also indicates that the oxygen is a lot more abundant than the carbon in the atmosphere. This potentially indicates that WASP-39 b originally formed far away from the central star.
By precisely revealing the details of an exoplanet atmosphere, the Webb telescope’s instruments performed well beyond scientists’ expectations — and promise a new phase of exploration of the broad variety of exoplanets in the galaxy.
“We are going to be able to see the big picture of exoplanet atmospheres,” said Laura Flagg, a researcher at Cornell University and a member of the international team. “It is incredibly exciting to know that everything is going to be rewritten. That is one of the best parts of being a scientist.”
More information
Webb is the largest, most powerful telescope ever launched into space. Under an international collaboration agreement, ESA provided the telescope’s launch service, using the Ariane 5 launch vehicle. Working with partners, ESA was responsible for the development and qualification of Ariane 5 adaptations for the Webb mission and for the procurement of the launch service by Arianespace. ESA also provided the workhorse spectrograph NIRSpec and 50% of the mid-infrared instrument MIRI, which was designed and built by a consortium of nationally funded European Institutes (The MIRI European Consortium) in partnership with JPL and the University of Arizona.
Webb is an international partnership between NASA, ESA and the Canadian Space Agency (CSA).
Charcoal and Cattle Correlate with Madagascar’s Megafaunal Extinctions
A new study suggests that changes in land use within the last millennia drove the extinction of Madagascar’s giant animals.
Excavation at Ankatoke, near Tampolove in Southwest Madagascar. Credits: Garth Cripps, 2018
The demise of the dodo epitomizes humanity’s record as a destructive force on delicate island life. Likewise, on the island of Madagascar, gorilla-sized lemurs, 3-meter tall elephant birds, and pygmy hippos went the way of the dodo following the arrival of humans within the last millennia.
But the factors behind the disappearance of these animals are not as well-known as in the case of the dodo, and there is intense debate about what caused the extinction of megafauna the world over.
Now, a new study in Scientific Reports suggests that, while humans had a hand in the extinction of these creatures, hunting alone wasn’t the main cause. While past studies have reported the butchery of endemic animals at least 2,000 years ago, the present study correlates the disappearance of endemic megafauna around 1,000 years ago with a sharp increase in introduced species and human-driven landscape change.
Charcoal and Cattle Correlate with Madagascar’s Megafaunal Extinctions: extirpated crocodile and extinct pygmy hippo bones excavated from Ankatok in a layer dating to 3,000 – 4,000 years ago. Credits: Garth Cripps, 2018
To understand the disappearance of Madagascar’s large animals, Hixon et al. excavated three coastal ponds and a cave from the southwest of the island and radiocarbon dated the remains of extinct megafauna, introduced animals, and other signs of human activity.
The researchers found that Madagascar’s megafauna had endured several dry periods over the last 6,000 years, relocating as needed when local water resources were scarce. Signs of human activity, including modified bones and shells, began appearing within the past 2,000 years.
At around 1,000 years ago, however, the researchers identified a drastic increase in charcoal and the bones of domesticated species, such as zebu cattle and dogs. The timing of these human-caused changes corresponds with the disappearance of megafauna.
“Our results suggest that occupation and alteration of space, through the burning of forests for introduced grazing species, drove the extinction of large animals on the island, rather than the mere presence of hunters,” says Sean Hixon, lead author of the paper.
In recent years, the debate over the causes of megafauna extinctions have largely focused on past climate change and overhunting by recent human arrivals. The new study suggests that while both of these may have been stress factors in Madagascar, they weren’t the ultimate cause of megafauna extinctions.
The article underscores that hunting isn’t the only way, or perhaps even the main way, that humans impact other species. In order to protect biodiversity, it is equally important to consider how human activities affect animal habitats and mobility.
The researchers hope that future studies will explore paleontological and archaeological deposits in other areas of the island to form a better understanding of when humans first arrived on Madagascar and how they interacted with their environment.
Press release from Max Planck Institute for Geoanthropology.
Webb Draws Back Curtain On Universe’s Early Galaxies
Telescope’s Infrared Vision Explores The Final Frontier
The powerful NASA/ESA/CSA James Webb Space Telescope has found an unexpectedly rich ‘undiscovered country’ of early galaxies that has been largely hidden until now.
A few days after officially starting science operations, the NASA/ESA/CSA James Webb Space Telescope propelled astronomers into a realm of early galaxies, previously hidden beyond the grasp of all other telescopes. Webb is now unveiling a very rich Universe where the first forming galaxies look remarkably different from the mature galaxies seen around us today. Researchers have found two exceptionally bright galaxies that existed approximately 300 and 400 million years after the Big Bang. Their extreme brightness is puzzling to astronomers. The young galaxies are transforming gas into stars as fast as they can and they appear compacted into spherical or disc shapes that are much smaller than our Milky Way galaxy. The onset of stellar birth may have been just 100 million years after the Big Bang, which happened 13.8 billion years ago.
“Everything we see is new. Webb is showing us that there’s a very rich Universe beyond what we imagined,” said Tommaso Treu of the University of California at Los Angeles, a co-investigator on one of the Webb programmes. “Once again the Universe has surprised us. These early galaxies are very unusual in many ways.”
The results are from Webb’s GLASS-JWST Early Release Science Program (Grism Lens-Amplified Survey from Space), and Cosmic Evolution Early Release Science Survey (CEERS). Two research papers, led by Marco Castellano of the National Institute for Astrophysics in Rome, Italy, and Rohan Naidu of the Center for Astrophysics | Harvard & Smithsonian and the Massachusetts Institute of Technology in Cambridge, Massachusetts have been published in the Astrophysical Journal Letters.
Two images showing thousands of galaxies of different colours, shapes, and sizes. In between the two images are two pull-outs showing details from the large images. Credit: NASA, ESA, CSA, T. Treu (UCLA)
In just four days of analysis, researchers found two exceptionally bright galaxies in the GLASS-JWST images. These galaxies existed approximately 450 and 350 million years after the Big Bang (with redshifts of approximately 10.5 and 12.5, respectively), which future spectroscopic measurements with Webb will help confirm.
“With Webb, we were amazed to find the most distant starlight that anyone had ever seen, just days after Webb released its first data,”
said Rohan Naidu of the more distant GLASS galaxy, referred to as GLASS-z12, which is believed to date back to 350 million years after big bang. The previous record holder is galaxy GN-z11, which existed 400 million years after the big bang (redshift 11.1), and identified in 2016 by Hubble and Keck Observatory in deep-sky programmes.
“Based on all the predictions, we thought we had to search a much bigger volume of space to find such galaxies,” said Castellano.
“These observations just make your head explode. This is a whole new chapter in astronomy. It’s like an archaeological dig, when suddenly you find a lost city or something you didn’t know about. It’s just staggering,” added Paola Santini, fourth author of the Castellano et al. GLASS-JWST paper.
“While the distances of these early sources still need to be confirmed with spectroscopy, their extreme brightnesses are a real puzzle, challenging our understanding of galaxy formation,” noted Pascal Oesch of the University of Geneva in Switzerland.
Graphic titled “James Webb Space Telescope: Pandora’s Cluster, Abell 2744,” with compass arrows, scale bar, and colour key for reference. Credit: NASA, ESA, CSA, T. Treu (UCLA)
The Webb observations nudge astronomers toward a consensus that an unusual number of galaxies in the early Universe were much brighter than expected. This will make it easier for Webb to find even more early galaxies in subsequent deep sky surveys, say researchers.
“We’ve nailed something that is incredibly fascinating. These galaxies would have had to have started coming together maybe just 100 million years after the Big Bang. Nobody expected that the dark ages would have ended so early,” said Garth Illingworth of the University of California at Santa Cruz. “The primal Universe would have been just one hundredth of its current age. It’s a sliver of time in the 13.8-billion-year-old evolving cosmos.”
Naidu/Oesch team member Erica Nelson of the University of Colorado noted that “our team was struck by being able to measure the shapes of these first galaxies; their calm, orderly discs question our understanding of how the first galaxies formed in the crowded, chaotic early Universe.” This remarkable discovery of compact discs at such early times was only possible because Webb’s images are so much sharper, in infrared light, than Hubble’s.
“These galaxies are very different from the Milky Way or other big galaxies we see around us today,” said Treu.
Illingworth emphasised that the two bright galaxies found by these teams have a lot of light. He said one option is that they could have been very massive, with lots of low-mass stars, like later galaxies. Alternatively, they could be much less massive, consisting of far fewer extraordinarily bright stars, known as Population III stars. Long theorised, they would be the first stars ever born, blazing at blistering temperatures and made up of only primordial hydrogen and helium; only later would stars cook up heavier elements in their nuclear fusion furnaces. No such extremely hot, primordial stars are seen in the local Universe.
“Indeed, the most distant source is very compact, and its colours seem to indicate that its stellar population is particularly devoid of heavy elements and could even contain some Population III stars. Only Webb spectra will tell,” said Adriano Fontana, second author of the Castellano et al. paper and a member of the GLASS-JWST team.
Present Webb distance estimates to these two galaxies are based on measuring their infrared colours. Eventually, follow-up spectroscopy measurements showing how light has been stretched in the expanding Universe will provide independent verification of these cosmic yardstick measurements.
Graphic titled “Abell 2744 GLASS JWST/NIRCam” with two large images showing thousands of galaxies of different colours, shapes, and sizes, and two smaller pull-outs showing details in the large images. Credit: NASA, ESA, CSA, T. Treu (UCLA)
More information
Webb is the largest, most powerful telescope ever launched into space. Under an international collaboration agreement, ESA provided the telescope’s launch service, using the Ariane 5 launch vehicle. Working with partners, ESA was responsible for the development and qualification of Ariane 5 adaptations for the Webb mission and for the procurement of the launch service by Arianespace. ESA also provided the workhorse spectrograph NIRSpec and 50% of the mid-infrared instrument MIRI, which was designed and built by a consortium of nationally funded European Institutes (The MIRI European Consortium) in partnership with JPL and the University of Arizona.
Webb is an international partnership between NASA, ESA and the Canadian Space Agency (CSA).
History of rhino images illustrates changing human-rhino relations and horn size
An international team of scientists, led by the University of Helsinki, has demonstrated that image databases can be used as an alternative to museum collections when studying long-term changes in human-nature interaction and as material in ecological and evolutionary research.
Most images produced in the first 300-400 years since the discovery of rhinos featured Indian rhinos, likely due to the fame of individual rhinos, like the one featured in a woodcut by Albrecht Dürer in 1515. Albrecht Dürer (1515): Woodcut of the Lisbon Rhinoceros by Albrecht Dürer (8th edition of the woodcut)
A joint analysis of artwork and photographs reveals how human attitudes towards rhinos have changed over time (from predation to conservation), and photo analysis shows a reduction in the size of rhinoceros horns in all rhinoceros species studied, possibly driven by human hunting.
Four of the five rhino species that survive today are threatened with extinction, despite their status as one of the most popular and recognizable groups of mammals today. Their declines have been driven by hunting for their horns, as well as loss of their habitats.
To best interpret the plight of rhinos, it is important to understand the history of their relationship with humans. Rhinos have been featured in European art for over 500 years, and this represents a valuable source of information for researchers. The Rhino Resource Center has gathered over 4000 images of rhinos and is the largest database of its kind in the world. A new study, published in People and Nature shows the importance of this resource for the first time.
Changing human-rhino relations
An international team of researchers set about answering questions related to the views that society has had on rhinos since the 16th century. They sought to answer how the different species had been represented through time, as well as how the frequency of images with a conservation or hunting focus have changed through time.
Most images produced in the first 300-400 years since the discovery of rhinos featured Indian rhinos, likely due to the fame of individual rhinos, like the one featured in a woodcut by Albrecht Dürer in 1515 or Clara, who went on a European tour in the 18th Century. Recent images have featured more white rhinos. This is the most common species today both in the wild and in captivity. During the expansion of European empires, there was an increase in the number of total rhino images and the number showing hunting. The collapse of these empires and the increasing awareness of the threat facing rhinos has been accompanied by a higher proportion of images painting rhinos in a more positive light and promoting conservation.
Hunting for horns
Rhinoceros horns are particularly difficult to study in museums; natural history collections containing rhinos are largely contained to former European colonies, and in the few European museums where rhino skeletons are found, their horns have been moved to protected facilities or destroyed. The reason for this is the high monetary value of horns among wildlife smugglers, which makes keeping horns a security risk. The new method based on image analysis therefore offers an interesting alternative solution for studying the change in horn size from photographs alone.
The researchers obtained evidence of the decrease in the size of the horns of rhinoceros species from the end of the 19th century to the present day by comparing the ratio of horn size to other body dimensions of individuals from photographs from different eras within each rhinoceros species. According to Doctoral Researcher Oscar Wilson, the lead author on the study, this follows a pattern seen in other animals. Wilson says:
“In other animals which are hunted for trophies, like elephants and wild sheep, the size of these trophies has got smaller over time as a result of natural selection. This suggests that the same thing might be happening with rhino horns.”
However, Wilson stresses that image-based analysis is not limited to rhinos. “Because they are so prominent in European art and the Rhino Resource Center was already well-curated, rhinos were a great place to start this investigation, but there’s no reason that image-based analyses couldn’t be applied to other animals. The same techniques would work very well for elephants or tapirs for example. The potential for the same types of resources to be developed for these animals is really exciting.”
The study was led by Doctoral Student Oscar Wilson at the University of Helsinki, in collaboration with Dr Michael Pashkevich and Dr Edgar Turner from the Insect Ecology Group in the Department of Zoology (Cambridge, UK) and Dr Kees Rookmaaker, Director and Chief Editor of the Rhino Resource Center (Utrecht, Netherlands).
Vocal Communication Originated over 400 Million Years Ago
Acoustic communication is not only widespread in land vertebrates like birds and mammals, but also in reptiles, amphibians and fishes. Many of them are usually considered mute, but in fact show broad and complex acoustic repertoires. According to researchers at the University of Zurich, the evolutionary origin of vocal communication dates back more than 400 million years.
Tuatara are found only on New Zealand islands and are considered living fossils. They also communicate acoustically. (Image: Gabriel Jorgewich Cohen)
The use of vocalizations as a resource for communication is common among several groups of vertebrates: singing birds, croacking frogs or barking dogs are some well-known examples. These vocalizations play a fundamental role in parental care, mate attraction and various other behaviors. Despite its importance, little is known about when and at what stage in the evolutionary history of vertebrates this behavior first appeared. Comparative analyses can provide insights into the evolutionary origin of acoustic communication, but they are often plagued by missing information from key groups that have not been broadly studied.
Acoustic abilities are widespread in land vertebrates
An international research team led by the University of Zurich (UZH) has therefore focused on species that have never been accessed before. Their study includes evidence for 53 species of four major clades of land vertebrates – turtles, tuataras, caecilians and lungfishes – in the form of vocal recordings and contextual behavioral information accompanying sound production.
“This, along with a broad literature-based dataset including 1800 different species covering the entire spectrum shows that vocal communication is not only widespread in land vertebrates, but also evidence acoustic abilities in several groups previously considered non-vocal,” says first author Gabriel Jorgewich-Cohen, PhD student at the Paleontological Institute and Museum of UZH.
Many turtles, for example, which were thought to be mute are in fact showing broad and complex acoustic repertoires.
Vocal Communication Originated over 400 Million Years Ago. The researchers were even able to detect acoustic communication in lungfish. (Image: Rafael C.B. Paradero)
Last common ancestor lived about 407 million years ago
To investigate the evolutionary origins of acoustic communication in vertebrates, the researchers combined relevant data on the vocalization abilities of species like lizards, snakes, salamanders, amphibians and dipnoi with phylogenetic trait reconstruction methods. Combined with data of well-known acoustic clades like mammals, birds, and frogs, the researchers were able to map vocal communication in the vertebrate tree of life.
“We were able to reconstruct acoustic communication as a shared trait among these animals, which is at least as old as their last common ancestor that lived approximately 407 million years before present,” explains Marcelo Sánchez, who led the study.
Acoustic communication did not evolve multiple times
So far, the scientific consensus favored a convergent origin of acoustic communication among vertebrates since the morphology in hearing apparatus and its sensitivity as well as the vocal tract morphology vary considerably among vertebrates. But according to the UZH researchers, the available evidence for this hypothesis lacks relevant data from key species so far considered non-vocal or neglected.
“Our results now show that acoustic communication did not evolve multiple times in diverse clades, but has a common and ancient evolutionary origin,” concludes Sánchez.
Literature:
Gabriel Jorgewich-Cohen, Simon William Townsend, Linilson Rodrigues Padovese, et al. Common evolutionary origin of acoustic communication in choanate vertebrates, Nature Communications, 25 October 2022. DOI: 10.1038/s41467-022-33741-8
Black Death shaped evolution of immunity genes, setting course for how we respond to disease today
An international team of scientists who analyzed centuries-old DNA from victims and survivors of the Black Death pandemic has identified key genetic differences that determined who lived and who died, and how those aspects of our immune systems have continued to evolve since that time.
Researchers from McMaster University, the University of Chicago, the Pasteur Institute and other organizations analyzed and identified genes that protected some against the devastating bubonic plague pandemic that swept through Europe, Asia and Africa nearly 700 years ago. Their study has been published in the journal Nature.
The same genes that once conferred protection against the Black Death are today associated with an increased susceptibility to autoimmune diseases such as Crohn’s and rheumatoid arthritis, the researchers report.
The team focused on a 100-year window before, during and after the Black Death, which reached London in the mid-1300s. It remains the single greatest human mortality event in recorded history, killing upwards of 50 per cent of the people in what were then some of the most densely populated parts of the world.
Using DNA extracted from teeth of people who died before, during and after the Black Death pandemic, researchers were able to identify genetic differences that dictated who survived and who died from the virus.
Credit: Matt Clarke/McMaster University
Researchers extracted DNA from the remains of people buried in the East Smithfield plague pits, which were used for mass burials in 1348 and 1349.
Courtesy: Museum of London Archaeology (MOLA)
Researchers extracted DNA from the remains of people buried in the East Smithfield plague pits, which were used for mass burials in 1348 and 1349.
Courtesy: Museum of London Archaeology (MOLA)
Researchers extracted DNA from the remains of people buried in the East Smithfield plague pits, which were used for mass burials in 1348 and 1349.
Courtesy: Museum of London Archaeology (MOLA)
Researchers extracted DNA from the remains of people buried in the East Smithfield plague pits, which were used for mass burials in 1348 and 1349.
Courtesy: Museum of London Archaeology (MOLA)
Researchers extracted DNA from the remains of people buried in the East Smithfield plague pits, which were used for mass burials in 1348 and 1349.
Evolutionary geneticist Hendrik Poinar has authored a new study, based on seven years of research, which found the genes that protected people against Black Death are associated with an increased susceptibility to autoimmune diseases.
Credit: JD Howell/McMaster University
Members of the Barreiro lab conduct cell culture experiments.
Courtesy: University of Chicago
More than 500 ancient DNA samples were extracted and screened from the remains of individuals who had died before the plague, died from it or survived the Black Death in London, including individuals buried in the East Smithfield plague pits used for mass burials in 1348-9. Additional samples were taken from remains buried in five other locations across Denmark.
Scientists searched for signs of genetic adaptation related to the plague, which is caused by the bacterium Yersinia pestis.
They identified four genes that were under selection, all of which are involved in the production of proteins that defend our systems from invading pathogens and found that versions of those genes, called alleles, either protected or rendered one susceptible to plague.
Individuals with two identical copies of a particular gene, known as ERAP2, survived the pandemic at a much higher rates than those with the opposing set of copies, because the ‘good’ copies allowed for more efficient neutralization of Y. pestis by immune cells.
“When a pandemic of this nature – killing 30 to 50 per cent of the population – occurs, there is bound to be selection for protective alleles in humans, which is to say people susceptible to the circulating pathogen will succumb. Even a slight advantage means the difference between surviving or passing. Of course, those survivors who are of breeding age will pass on their genes,” explains evolutionary geneticist Hendrik Poinar, an author of the Nature paper, director of McMaster’s Ancient DNA Centre, and a principal investigator with the Michael G. DeGroote Institute for Infectious Disease Research and McMaster’s Global Nexus for Pandemics & Biological Threats.
Europeans living at the time of the Black Death were initially very vulnerable because they had had no recent exposure to Yersinia pestis. As waves of the pandemic occurred again and again over the following centuries, mortality rates decreased.
Researchers estimate that people with the ERAP2 protective allele (the good copy of the gene, or trait), were 40 to 50 per cent more likely to survive than those who did not.
“The selective advantage associated with the selected loci are among the strongest ever reported in humans showing how a single pathogen can have such a strong impact to the evolution of the immune system,” says human geneticist Luis Barreiro, an author on the paper, and professor in Genetic Medicine at the University of Chicago.
Black Death shaped evolution of immunity genes, setting course for how we respond to disease today. Using DNA extracted from teeth of people who died before, during and after the Black Death pandemic, researchers were able to identify genetic differences that dictated who survived and who died from the virus. Credit: Matt Clarke/McMaster University
The team reports that over time our immune systems have evolved to respond in different ways to pathogens, to the point that what had once been a protective gene against plague in the Middle Ages is today associated with increased susceptibility to autoimmune diseases. This is the balancing act upon which evolution plays with our genome.
“This highly original work has been possible only through a successful collaboration between very complementary teams working on ancient DNA, on human population genetics and the interaction between live virulent Yersinia pestis and immune cells,” says Javier Pizarro-Cerda, head of the Yersinia Research Unit and director of the World Health Organization Collaborating Centre for Plague at the Pasteur Institute.
“Understanding the dynamics that have shaped the human immune system is key to understanding how past pandemics, like the plague, contribute to our susceptibility to disease in modern times,” says Poinar.
The findings, the result of seven years of work from graduate student Jennifer Klunk, formally of McMaster’s Ancient DNA Centre and postdoctoral fellow Tauras Vigylas, from the University of Chicago, allowed for an unprecedented look at the immune genes of victims of the Black Death.
The research was funded in part by the Social Sciences and Humanities Research Council of Canada (SSHRC), The National Institutes of Health (NIH) and the Canadian Institute for Advanced Research, under the Humans and the Microbiome program.
Press release from McMaster University, by Michelle Donovan on how the Black Death shaped the evolution of immunity genes, setting course for how we respond to disease today.
WWII shipwreck has leaked many pollutants into the sea, changing the ocean floor around it
Researchers have discovered that an 80 year old historic World War II shipwreck is still influencing the microbiology and geochemistry of the ocean floor where it rests. In Frontiers in Marine Science, they show how the wreck is leaking hazardous pollutants, such as explosives and heavy metals, into the ocean floor sediment of the North Sea, influencing the marine microbiology around it.
The seabed of the North Sea is covered in thousands of ship and aircraft wrecks, warfare agents, and millions of tons of conventional munition such as shells and bombs. Wrecks contain hazardous substances (such as petroleum and explosives) that may harm the marine environment. Yet, there is a lack of information about the location of the wrecks, and the effect they might have on the environment.
“The general public is often quite interested in shipwrecks because of their historical value, but the potential environmental impact of these wrecks is often overlooked,” said PhD candidate Josefien Van Landuyt, of Ghent University.
For example, it is estimated that World War I and II shipwrecks around the world collectively contain between 2.5m and 20.4m tons of petroleum products.
“While wrecks can function as artificial reefs and have tremendous human story-telling value, we should not forget that they can be dangerous, human-made objects which were unintentionally introduced into a natural environment,” Van Landuyt continued. “Today, new shipwrecks are removed for this exact reason.”
As part of the North Sea Wrecks project, Van Landuyt and her colleagues investigated how the World War II shipwreck V-1302 John Mahn in the Belgian part of the North Sea is impacting the microbiome and geochemistry in its surrounding seabed.
“We wanted to see if old shipwrecks in our part of the sea (Belgium) were still shaping the local microbial communities and if they were still affecting the surrounding sediment. This microbial analysis is unique within the project,” explained Van Landuyt.
Dangerous chemicals and corroding microbes
The V-1302 John Mahn was a German fishing trawler that was requisitioned during World War II to use as a patrol boat. In 1942, during ‘the Channel Dash’, it was attacked by the British Royal Air Force in front of the Belgian coast, where it quickly sank to the bottom of the sea.
To analyze the bio- and geochemistry around the shipwreck, the researchers took steel hull and sediment samples from and around it, at an increasing distance from it and in different directions.
They found varying degrees of concentrations of toxic pollutants depending on the distance from the shipwreck. Most notably, they found heavy metals (such as nickel and copper), polycyclic aromatic hydrocarbons (PAHs; chemicals that occur naturally in coal, crude oil, and gasoline), arsenic, and explosive compounds.
The highest metal concentrations were found in the sample closest to the ship’s coal bunker. The freshly deposited sediment in the wake of the wreck had a high metal content. The highest PAH concentrations were closest to the ship.
“Although we don’t see these old shipwrecks, and many of us don’t know where they are, they can still be polluting our marine ecosystem,” explained Van Landuyt.
“In fact, their advancing age might increase the environmental risk due to corrosion, which is opening up previously enclosed spaces. As such, their environmental impact is still evolving.”
They also found that the ship influenced the microbiome around it. Known PAH degrading microbes like Rhodobacteraceae and Chromatiaceae were found in samples with the highest pollutant content. Moreover, sulfate reducing bacteria (such as Desulfobulbia) were present in the hull samples, likely leading to the corrosion of the steel hull.
Forgotten polluters
This study is only the tip of the iceberg, Van Landuyt explained: “People often forget that below the sea surface, we, humans, have already made quite an impact on the local animals, microbes, and plants living there and are still making an impact, leaching chemicals, fossil fuels, heavy metals from — sometimes century old — wrecks we don’t even remember are there.”
“We only investigated one ship, at one depth, in one location. To get a better overview of the total impact of shipwrecks on our North Sea, a large number of shipwrecks in various locations would have to be sampled,” Van Landuyt concluded.
Press release from Frontiers
Sunken WW II warship continues to leak hazardous substances
A shipwreck from the Second World War is still leaking hazardous substances into the North Sea. Bio-engineers from Ghent University teamed up with the Flanders Marine Institute (VLIZ) to study the impact of this shipwreck on marine life.
Location of the wreck of the fishing boat V-1302 John Mahn in the North Sea
The bed of the North Sea is littered with thousands of shipwrecks and planes from the war, and these contain all kinds of hazardous substances, such as explosives and petroleum.
Among these wrecks is the fishing boat V-1302 John Mahn. This was captured by the Germans during the Second World War and used as a patrol ship. In 1942, the John Mahn was struck off the Belgian coast during air attacks by the British Airforce when it was part of Operation Cerberus, a convoy of over 200 ships, which were required to escort German warships from Brittany to German ports. The ship sank quickly to the bottom of the sea. Other than a missing superstructure and large tear on the port side, the wreck is still very intact.
Bio-engineer Josefien Van Landuyt examined samples of sediment in the area around the sunken John Mahn. In doing so, she aimed to discover whether old shipwrecks in the Belgian section of the North Sea continue to affect microbial marine life.
Fishing boat V-1302 John Mahn. The WWII shipwreck has leaked many pollutants into the sea
Substances found
“We found varying levels of toxic substances, depending on how far from the shipwreck the samples were taken: predominantly heavy metals, such as nickel and copper, arsenic, explosive substances and chemicals that naturally occur in coal, crude oil and petrol”, explains Josefien. “The wreck also has an impact on the micro-organisms in the area: we discovered different microbes and bacteria than in other parts of the sea.”
How dangerous is it?
“In fact, it’s not too bad”, says Josefien. “The quantities of hazardous substances involved are pretty small. Yet what’s remarkable is the fact that the impact of the wreck is still present, even 80 years on. Also, we don’t know how this wreck will evolve: the fuel tank might still be intact and could start leaking in the future. Further investigations are needed to find out.”
Impact on marine life
“It’s all relative. If you view the wreck purely as a construction, you could even say that it has a positive impact on biodiversity. You could see it as an artificial reef; this is an interesting environment for all kinds of animal and plant species.”
“Furthermore, the chemical substances and metals in the shipwreck caused the appearance of other types of bacteria, which use these chemical substances and metals as a source of energy. You could consider it a natural solution for the contamination issue.”
Other wrecks
“In addition to this one, there are also many other shipwrecks at the bottom of the North Sea. With its North Sea Wrecks project, the Flanders Marine Institute is investigating which wrecks are where and in what condition. My research is part of this project. Much work remains before there is a complete picture of the number of shipwrecks and the risks they present”, confirms Josefien.
Bibliographic information:
Van Landuyt, J.; Kundu, K.; Van Haelst, S.; Neyts, M.; Parmentier, K.; De Rijcke, M. and Boon, N. (2022, October 18). 80 years later: Marine sediments still influenced by an old war ship. In Frontiers in Marine Science, Sec. Aquatic Microbiology, https://www.frontiersin.org/articles/10.3389/fmars.2022.1017136/full
Press release from Ghent University on the WWII shipwreck still leaking pollutants into the sea.
Watch brain cells in a dish learn to play Pong in real time
Human and mouse neurons in a dish learned to play the video game Pong, researchers report October 12 in the journal Neuron. The experiments are evidence that even brain cells in a dish can exhibit inherent intelligence, modifying their behavior over time.
“From worms to flies to humans, neurons are the starting block for generalized intelligence,” says first author Brett Kagan (@ANeuroExplorer), chief scientific officer at Cortical Labs in Melbourne, Australia. “So, the question was, can we interact with neurons in a way to harness that inherent intelligence?”
To start, the researchers connected the neurons to a computer in such a way where the neurons received feedback on whether their in-game paddle was hitting the ball. They monitored the neuron’s activity and responses to this feedback using electric probes that recorded “spikes” on a grid.
The spikes got stronger the more a neuron moved its paddle and hit the ball. When neurons missed, their playstyle was critiqued by a software programcreated by Cortical Labs. This demonstrated that the neurons could adapt activity to a changing environment, in a goal-oriented way, in real time.
Watch the video to see the brain cells in a dish learning to play Pong in real time. Picture by Eric Perlin
“We chose Pong due to its simplicity and familiarity, but, also, it was one of the first games used in machine learning, so we wanted to recognize that,” says Kagan, who worked with collaborators from 10 other institutions on the project.
“An unpredictable stimulus was applied to the cells, and the system as a whole would reorganize its activity to better play the game and to minimize having a random response,” he says. “You can also think that just playing the game, hitting the ball and getting predictable stimulation, is inherently creating more predictable environments.”
The theory behind this learning is rooted in the free-energy principle. Simply put, the brain adapts to its environment by changing either its world view or its actions to better fit the world around it.
Pong wasn’t the only game the research team tested. “You know when the Google Chrome browser crashes and you get that dinosaur that you can make jump over obstacles (Project Bolan). We’ve done that and we’ve seen some nice preliminary results, but we still have more work to do building new environments for custom purposes,” says Kagan.
Future directions of this work have potential in disease modeling, drug discoveries, and expanding the current understanding of how the brain works and how intelligence arises.
“This is the start of a new frontier in understanding intelligence,” Kagan says. “It touches on the fundamental aspects of not only what it means to be human but what it means to be alive and intelligent at all, to process information and be sentient in an ever changing, dynamic world.”
Researcher retrieved archival information that attributes a pseudonymous astronomical treatise to Galileo Galilei
Aresearcher at the Department of Philosophy and Cultural Heritage of Ca’ Foscari University of Venice, Dr Matteo Cosci, has retrieved archival information which confirms that the treatise Considerazioni Astronomiche di Alimberto Mauri (1606) was in fact written by Galileo Galilei, the illustrious mathematician from Pisa. Galileo used a pseudonym and the author’s uncertain identity had not been confirmed until now. Dr Cosci closely examined original documents preserved at the National Central Library of Florence for the purpose.
Book front page
Not only forged documents
Before this discovery was made, the New York Times had revealed that some of Galileo’s documents held at the University of Michigan and at Morgan Library in New York City were in fact counterfeits made by the infamous forger Tobia Nicotra in the early 20th century. Professor Nick Wilding of Georgia State University, who discovered the counterfeit, demonstrated that the filigree of the paper that the texts were written on cannot predate the 18th century.
When these documents were authenticated at the start of the 20th century, the authentication process was based on other documents attributed to Galileo, which were subsequently revealed to also be forgeries. One of such documents was a counterfeit letter signed by Galileo that was thought to accompany a book entitled “Libro della Considerazione Astronomica”. Starting in the late 1970s, in order to explain the reasons behind this letter, scholars hypothesised that the accompanying letter was proof that Galileo had actually written a controversial treatise, Considerazioni Astronomiche di Alimberto Mauri. This treatise was known to have been written under pseudonym, and since its publication in 1606 it had been attributed by some to Galileo himself. For one, Fortunio Liceti — Galileo’s colleague at the University of Padua — referred to Aliberto Mauri as someone who “pretended” to be an astronomer though he might rather have been an expert mathematician.
However, the true identity of the author was never establishedwith certainty. In the view of some scholars, the accompanying letter — which is currently hosted in the Fondo “Cardinale Pietro Maffi” in Pisa — seemed to confirm that Galileo was indeed the author of the Considerazioni Astronomiche. Despite the fact that now the only document which seemed to support the ascription of authorship to Galileo has been declared false, the emergence of different original documents makes this identification certain.
The retrieval
Matteo Cosci found important information among the papers in the collection “Gal. 42” at Biblioteca Nazionale Centrale di Firenze, which contains Galileo’s Frammenti e primi abbozzi relativi al trattato galileiano“Delle cose che stanno su l’acqua”. On the whole, these handwritten papers are a collection of notes taken in different periods of time and on different topics, including some references to the “stella nova” (new star) of 1604 that diverge from the interpretation that at the time was being given by the Florentine philosopher Lodovico Delle Colombe.
Matteo Cosci
Even though they were not about the same topic, Galileo’s brief notes on the “new star” were evidently collected together with his others about the floating bodies because they were addressed against the same opponent. Dr Cosci noticed both their apparent misplacement and their peculiarity while he was systematically examining all the handwritten drafts of Galileo on the “new star” dispute. Previous cataloguing of this material had already confirmed that it was written by Galileo in opposition to Lodovico Delle Colombe’s writings. However, these notes had never been considered relevant enough to be included in the national edition of Galileo’s work — in fact, they remain unpublished.
Among these papers by Galileo, on page 31 recto, there is a list of “places where [Lodovico Delle Colombe] speaks of me with contempt.” Dr Cosci noticed that those “places” are precise references to some selected textual passages in Lodovico Delle Colombe’s Risposte (i.e. Answers). Then he realised that those passages do not openly attack Galileo (who is never even mentioned), but do attack Alimberto Mauri. The fact that Galileo felt personally “attacked” whenever Alimberto Mauri was attacked in print confirms that Alimberto Mauri was his alter ego. Simply put, in these private notes, Galilei himself reveals his identity as the one hiding behind a pseudonym.
Overall, the autographic documents examined by Matteo Cosci are currently the only authentic piece of documentary evidence that enables the attribution of Considerazioni Astronomiche to Galileo.
Why did Galileo use a pseudonym?
Galileo was successfully working in Padua, but his salary no longer suited his own needs and his family requirements. As Stillman Drake previously hypothesised, Galileo published this treatise in an attempt to find patronage beyond the borders of the Venetian Republic, and more specifically in Rome — in fact, the treatise was dedicated to none other than the Pope’s Treasurer. However, those were the years of the Venetian Interdict (a diplomatic quarrel between the Papal Curia and the Republic of Venice), so it would have been unwise of Galileo to place his name on a treatise that was dedicated to the public enemy.
Galilei had used pseudonyms before. He had participated with the assistance of one of his students in a debate on the same star using the pseudonym “Cecco da Ronchitti”. In fact, Lodovico Delle Colombe indirectly addressed Galileo as “la Signora maschera” (i.e. Mr. Mask), “Mauri”, “Cecco”, and “quel dottor che leggeva in Padova” (i.e. “that professor that was a lecturer in Padua”). Delle Colombe subsequently wrote his Risposte keeping Galileo in mind, but hesitating to openly identify his adversary. This, too, contributed to the general sense of uncertainty over authorship. Another note discovered by Dr Cosci shows that that Galileo initially wanted to reply further to Lodovico Delle Colombe, but he concluded that in the end the opponent did not even deserve his time. Nevertheless, the dispute between Galileo and Lodovico Delle Colombe continued and escalated during the first years of Galilei’s stay in Florence, when the use of a pseudonym was no longer necessary for the by then famous author of the Sidereus Nuncius.
Conclusions
The radical re-examination of these unpublished documents has confirmed the attribution of Considerazioni astronomiche to Galileo Galilei. The treatise — a new edition of which is being prepared by Dr Cosci — shows textual similarities with other writings of Galileo on different topics and from different periods of time, such as De Motu, Considerazioni circa l’opinione copernicana, and Dialogo di Cecco da Ronchitti, as well as with a postilla on his copy of Delle Colombe’s text on the new star. Moreover, at the time of the debate, the student Willem van Thienen had added in plain the name “Galileo Galilei” on his copy of Risposte, just below the title “certa maschera saccente nominata Alimberto Mauri” (“a knowing mask named Alimberto Mauri”).
Professor Nick Wilding has commented:
‘This is an excellent example of how patient and intelligent archival research can restore some of the damage inflicted by forgers. Dr Cosci has shown us that a combination of scepticism and skill will lead us to historical truth.’
In addition, Prof. Peter Barker (University Of Oklahoma),who has been aware of Cosci’s research, claimed:
‘Sidereus Nuncius tells us when, how and what Galileo made telescopic observations about. But the perspective of Considerazioni Astronomiche shows uswhyhe made those observations three years later.’
In sum, a new chapter can be added to the monumental collection of writings by the person who revolutionised Western science. Among the most interesting arguments in this work can be listed, for instance, the hypothesis of existence of mountains on the surface of the moon from a purely perspectivist point of view, the idea that physical causes are the actual reasons for explaining the regularity of celestial motions that apparently follow nonuniform paths, and the criticism of those who reject astrology without having the necessary astronomical knowledge to properly do so.
Therefore, Considerazioni Astronomiche di Alimberto Mauri is written by an unusual, yet recognisable Galileo, during a transition phase in which he was at once looking for new patronage and trying to confute the most retrograde Aristotelian tenets, just a few years before his discoveries with the telescope would lead him to move to Florence and then make him famous all over the world. For that matter, the printing privilege informs us that the treatise was published in Florence with the assent of Paolo Vinta, prime secretary of the Grand Duchy and brother of Belisario, who was in turn Galileo’s friend, correspondent and shortly afterwards mediator for his desired rerturn in Tuscany.
The study leading to this result was originated within the ERC research project “Aristotle in the Italian Vernacular: Rethinking Renaissance and Early-Modern Intellectual History (c. 1400–c. 1650)” , and that is currently being pursued at Ca’ Foscari in partnership with the Department of History of Science, Technology, and Medicine of the Università of Oklahoma within the Marie Skłodowska-Curie project “The Ophiucus Supernova: Post-Aristotelian stargazing in the European context (1604-1654)”, which Dr Cosci is responsible for.
Bibliographic information:
– 15/07/2022: Matteo Cosci, “Galileo’s pseudonymous project for his treatise on the ‘Stella Nova’ of 1604”, Department of History of Science, Technology, and Medicine, University of Oklahoma; Norman, Oklahoma.
– 24/03/2022: Matteo Cosci, “Galileo alias Alimberto Mauri: nuove evidenze documentarie per una nuova edizione delle Considerazioni”, Project Workshop, “Teorie e pratiche astrologiche al tempo di Galileo Galilei”, with Elide Casali and Monica Azzolini (Discussant: H. Darell Rutkin), Aula Morelli/Biral, Malcanton Marcorà, Dipartimento di Filosofia e Beni Culturali, Venice Ca’ Foscari University. https://www.unive.it/data/33113/1/59122
Press release from Ca’ Foscari University of Venice
