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Tag: Evolution and Darwin

  • The Complete Library of Charles Darwin revealed for the first time

    The Complete Library of Charles Darwin revealed for the first time


    Newswise — Charles Darwin – arguably the most influential man of science in history, accumulated a vast personal library throughout his working life. Until now, 85 per cent of its contents were unknown or unpublished. 

    This year, coinciding with Darwin’s 215th birthday, The Complete Work of Charles Darwin Online, the scholarly project helmed by Dr John van Wyhe at the National University of Singapore (NUS) Department of Biological Sciences, has released an online 300-page catalogue detailing Darwin’s complete personal library, with 7,400 titles across 13,000 volumes and items including books, pamphlets and journals. Previous lists only had 15 per cent of his whole collection. Darwin’s library has also been virtually re-assembled with 9,300 links to copies of the works freely available online.

    “This unprecedentedly detailed view of Darwin’s complete library allows one to appreciate more than ever that he was not an isolated figure working alone but an expert of his time building on the sophisticated science and studies and other knowledge of thousands of people. Indeed, the size and range of works in the library makes manifest the extraordinary extent of Darwin’s research into the work of others,” said Dr van Wyhe.

    Discovering Darwin’s complete library

    After his death in 1882, much of Darwin’s library was preserved and catalogued, but many other items were dispersed or lost, and details of the vast majority of the contents have never been published until now. For many years, scholars have referred to Darwin’s library as containing 1,480 books, based on those that survive in the two main collections, the University of Cambridge and Down House.

    Over 18 years the Darwin Online project has identified thousands of Darwin’s obscure references in his own catalogues and lists of items such as pamphlets and journals that were originally in his library. Each reference required its own detective story to discover the publications that Darwin had hurriedly recorded. In addition, missing details such as author, date or the source of clippings in thousands of records from older catalogues have been identified for the first time.

    A major source of information that helped to reveal the original contents is the 426-page handwritten “Catalogue of the Library of Charles Darwin”, compiled from 1875. Painstaking comparison of its abbreviated entries revealed 440 unknown titles that were originally in the library. An inventory of his home made after his death recorded 2,065 bound books and an unknown number of unbound volumes and pamphlets. In the drawing room, 133 titles and 289 volumes of mostly unscientific literature were recorded. Amazingly, the legacy duty valuer estimated that the “Scientific Library that is books relating to Science” was worth only 30 pounds and 12 shillings [about £2,000 today] Indeed, all the books were valued at only66 pounds and 10 shillings [about £4,400 today]. Today any book that belonged to Darwin is worth a great deal to collectors.

    Other sources of information that helped to build Darwin’s complete library were lists of pamphlets, Darwin’s reading notebooks, Emma Darwin’s diaries, the Catalogue of books given to the Cambridge Botany School in 1908 and the 30 volumes of the Darwin Correspondence. Items that still exist but were never included in the lists of Darwin’s library include his unbound materials at Cambridge University Library, books now in other institutional collections, private collections and books sold at auctions over the past 130 years. Combining these and many other sources of evidence allowed Darwin’s library to be reconstructed.

    For example, Darwin’s copy of an 1826 article by the ornithologist John James Audubon: ‘Account of the habits of the Turkey Buzzard (Vultura aura), particularly with the view of exploding the opinion generally entertained of its extraordinary power of smelling’ was sold in 1975. Darwin had investigated this point during the voyage of the Beagle and recorded reading a critic of Audubon in the lost Galapagos notebook. In 2019, a copy of Elizabeth Gaskell’s 1880 novel Wives and daughters appeared at auction. A note in it records: “This book was a great favourite of Charles Darwin’s and the last book to be read aloud to him.”

    Understanding Darwin’s library

    Most of the works in Darwin’s library are, unsurprisingly, on scientific subjects, especially biology and geology. Yet, the library also included works on farming, animal breeding and behaviour, geographical distribution, philosophy, psychology, religion, and other topics that interested Darwin, such as art, history, travel and language. Most of the works are in English, but almost half are in other languages, especially German, French and Italian as well as Dutch, Danish, Spanish, Swedish and Latin.

    Some of the hundreds of books not previously known to be in Darwin’s library include Sun Pictures, a 1872 coffee table book showcasing photographs of artworks. Another book that the we did not know that the Darwins purchased was a copy of the popular science book on gorillas that was all the rage just after Origin of species was published: Paul Du Chaillu’s Explorations and adventures in equatorial Africa. Of the thousands of shorter items were also found in Darwin’s library, such as an issue of a German scientific periodical sent to him in 1877 that contained the first published photographs of bacteria and another article amusingly entitled The hateful or Colorado grasshopper. In his complete library, Darwin’s eclectic sources are there for all to see.

    Click to view The Complete Library of Charles Darwin

    Click to view Introduction to the Library by John van Wyhe





    National University of Singapore (NUS)

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  • Some mosquitoes like it hot

    Some mosquitoes like it hot

    Newswise — Certain populations of mosquitoes are more heat tolerant and better equipped to survive heat waves than others, according to new research from Washington University in St. Louis.

    This is bad news in a world where vector-borne diseases are an increasingly global health concern. Most models that scientists use to estimate vector-borne disease risk currently assume that mosquito heat tolerances do not vary. As a result, these models may underestimate mosquitoes’ ability to spread diseases in a warming world.

    Researchers led by Katie M. Westby, a senior scientist at Tyson Research Center, Washington University’s environmental field station, conducted a new study that measured the critical thermal maximum (CTmax), an organism’s upper thermal tolerance limit, of eight populations of the globally invasive tiger mosquito, Aedes albopictus. The tiger mosquito is a known vector for many viruses including West Nile, chikungunya and dengue.

    “We found significant differences across populations for both adults and larvae, and these differences were more pronounced for adults,” Westby said. The new study is published Jan. 8 in Frontiers in Ecology and Evolution.

    Westby’s team sampled mosquitoes from eight different populations spanning four climate zones across the eastern United States, including mosquitoes from locations in New Orleans; St. Augustine, Fla.; Huntsville, Ala.; Stillwater, Okla.; St. Louis; Urbana, Ill.; College Park, Md.; and Allegheny County, Pa.

    The scientists collected eggs in the wild and raised larvae from the different geographic locations to adult stages in the lab, tending the mosquito populations separately as they continued to breed and grow. The scientists then used adults and larvae from subsequent generations of these captive-raised mosquitoes in trials to determine CTmax values, ramping up air and water temperatures at a rate of 1 degree Celsius per minute using established research protocols.

    The team then tested the relationship between climatic variables measured near each population source and the CTmax of adults and larvae. The scientists found significant differences among the mosquito populations.

    The differences did not appear to follow a simple latitudinal or temperature-dependent pattern, but there were some important trends. Mosquito populations from locations with higher precipitation had higher CTmax values. Overall, the results reveal that mean and maximum seasonal temperatures, relative humidity and annual precipitation may all be important climatic factors in determining CTmax.

    “Larvae had significantly higher thermal limits than adults, and this likely results from different selection pressures for terrestrial adults and aquatic larvae,” said Benjamin Orlinick, first author of the paper and a former undergraduate research fellow at Tyson Research Center. “It appears that adult Ae. albopictus are experiencing temperatures closer to their CTmax than larvae, possibly explaining why there are more differences among adult populations.”

    “The overall trend is for increased heat tolerance with increasing precipitation,” Westby said. “It could be that wetter climates allow mosquitoes to endure hotter temperatures due to decreases in desiccation, as humidity and temperature are known to interact and influence mosquito survival.”

    Little is known about how different vector populations, like those of this kind of mosquito, are adapted to their local climate, nor the potential for vectors to adapt to a rapidly changing climate. This study is one of the few to consider the upper limits of survivability in high temperatures — akin to heat waves — as opposed to the limits imposed by cold winters.

    “Standing genetic variation in heat tolerance is necessary for organisms to adapt to higher temperatures,” Westby said. “That’s why it was important for us to experimentally determine if this mosquito exhibits variation before we can begin to test how, or if, it will adapt to a warmer world.”

    Future research in the lab aims to determine the upper limits that mosquitoes will seek out hosts for blood meals in the field, where they spend the hottest parts of the day when temperatures get above those thresholds, and if they are already adapting to higher temperatures. “Determining this is key to understanding how climate change will impact disease transmission in the real world,” Westby said. “Mosquitoes in the wild experience fluctuating daily temperatures and humidity that we cannot fully replicate in the lab.”

    Washington University in St. Louis

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  • Mathematical framework for evolutionary developmental dynamics (evo-devo).

    Mathematical framework for evolutionary developmental dynamics (evo-devo).

    Newswise — Natural selection acts on phenotypes constructed over development, which raises the question of how development affects evolution. Classic evolutionary theory indicates that development affects evolution by modulating the genetic covariation upon which selection acts, thus affecting genetic constraints. However, whether genetic constraints are relative, thus diverting adaptation from the direction of steepest fitness ascent, or absolute, thus blocking adaptation in certain directions, remains uncertain. This limits understanding of long-term evolution of developmentally constructed phenotypes. Here we formulate a general, tractable mathematical framework that integrates age progression, explicit development (i.e., the construction of the phenotype across life subject to developmental constraints), and evolutionary dynamics, thus describing the evolutionary and developmental (evo-devo) dynamics. .The framework yields simple equations that can be arranged in a layered structure that we call the evo-devo process, whereby five core elementary components generate all equations including those mechanistically describing genetic covariation and the evo-devo dynamics. The framework recovers evolutionary dynamic equations in gradient form and describes the evolution of genetic covariation from the evolution of genotype, phenotype, environment, and mutational covariation. This shows that genotypic and phenotypic evolution must be followed simultaneously to yield a dynamically sufficient description of long-term phenotypic evolution in gradient form, such that evolution described as the climbing of a fitness landscape occurs in “geno-phenotype” space. Genetic constraints in geno-phenotype space are necessarily absolute because the phenotype is related to the genotype by development. Thus, the long-term evolutionary dynamics of developed phenotypes is strongly non-standard: (1) evolutionary equilibria are either absent or infinite in number and depend on genetic covariation and hence on development; (2) developmental constraints determine the admissible evolutionary path and hence which evolutionary equilibria are admissible; and (3) evolutionary outcomes occur at admissible evolutionary equilibria, which do not generally occur at fitness landscape peaks in geno-phenotype space, but at peaks in the admissible evolutionary path where “total genotypic selection” vanishes if exogenous plastic response vanishes and mutational variation exists in all directions of genotype space. Hence, selection and development jointly define the evolutionary outcomes if absolute mutational constraints and exogenous plastic response are absent, rather than the outcomes being defined only by selection. Moreover, our framework provides formulas for the sensitivities of a recurrence and an alternative method to dynamic optimization (i.e., dynamic programming or optimal control) to identify evolutionary outcomes in models with developmentally dynamic traits. These results show that development has major evolutionary effects.

    University of St. Andrews

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  • La explicación científica detrás de algunas reacciones extrañas del cuerpo

    La explicación científica detrás de algunas reacciones extrañas del cuerpo

    Newswise — EAU CLAIRE, Wisconsin — A diario, el cuerpo hace algunas cosas bastante extrañas e inusuales. A continuación, se incluyen algunas preguntas y respuestas que ofrecen la explicación científica de por qué suceden.

    ¿Por qué se arrugan los dedos de las manos en el agua?

    Inicialmente, se pensaba que los dedos se arrugaban en el agua por los cambios en los líquidos que ocurren entre los tejidos y el agua en la que están inmersos. Expertos en evolución hallaron evidencia de que esto puede haber permitido a los seres humanos a agarrar mejor los objetos bajo el agua. A las personas con lesiones nerviosas en los dedos de las manos o de los pies generalmente no se les arrugan los dedos de la misma forma.

    ¿Por qué a veces siento un pulso en los oídos?

    El pulso en los oídos puede deberse a diversos motivos. El tinnitus suele describirse como un timbre en los oídos, pero existe una variación en la que la persona siente y escucha el pulso en los oídos. Esto se denomina tinnitus pulsátil. Un aumento en la presión arterial o una obstrucción en el conducto auditivo puede ocasionar que la persona escuche el pulso. Otra causa puede ser una anomalía en las arterias próximas a los oídos. Este es un motivo para consultar con su equipo de atención médica.

    ¿Por qué tiritamos cuando hace frío?

    Tiritar cuando hace frío es una manera de hacer temblar a los músculos para generar calor. El cuerpo siempre intenta mantener la temperatura lo más cercana posible a 98,6 grados (37 °C).

    ¿Por qué algunas personas estornudan cuando miran el sol?

    Esto se conoce como reflejo del estornudo fótico. La explicación teórica detrás de esta reacción es la siguiente: el nervio óptico, que detecta un cambio en la luz, está ubicado cerca del nervio trigémino, que controla los estornudos. Un estornudo típico se produce por una irritación en la nariz, que activa al nervio trigémino y desencadena un estornudo. Al salir de una habitación a oscuras hacia un lugar con iluminación brillante, las pupilas se contraen. Este reflejo rápido se inicia en el nervio óptico y puede dar la sensación de irritación en la nariz, lo que genera el estornudo. No todas las personas tienen esta reacción, y no está claro por qué algunas la tienen y otras no.

    ¿Por qué siento una punzada en el costado al correr?

    Las punzadas en el costado se ocasionan por la irritación del diafragma, un músculo que separa la cavidad pulmonar y la cavidad abdominal. Los corredores novatos o quienes incrementan el ritmo o la distancia tienen más probabilidades de sentir punzadas en el costado. En ocasiones, la causa es una respiración demasiado rápida o una alimentación inapropiada antes de correr. Si siente una punzada en el costado, disminuya la velocidad, estire los músculos del torso y concéntrese en respirar lenta y regularmente.

    ¿Por qué el párpado comienza a contraerse de repente?

    La contracción del párpado se llama blefaroespasmo. Se desconoce la causa exacta, pero se suele atribuir a la fatiga, al consumo de cafeína y al estrés. Se recomienda estirar el músculo que se está contrayendo halándolo suavemente con la punta de los dedos en el área y descansar bien. En general, la contracción desaparece sola. Si la contracción dura más de un par de días o tiene dificultad para abrir el párpado, será necesario que lo vea un profesional de atención médica.

    — Amy Rantala, M.D., atiende pacientes en Ortopedia y Medicina Deportiva en Eau Claire, Wisconsin.

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    Mayo Clinic

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  • Rough draft of Darwin’s Origin of species goes online

    Rough draft of Darwin’s Origin of species goes online

    Newswise — On the 164th anniversary of Charles Darwin’s Origin of species, the Darwin Online project at the National University of Singapore (NUS) will launch all the surviving draft pages of one of the most influential scientific books in history. After his book was published, the unsentimental Darwin discarded the hundreds of pages of the original handwritten draft of his epoch-making book into the Darwin family’s scrap paper pile. His children used some sheets for drawings and others were torn in half by one of Darwin’s son who used the blank back sides for mathematical exercises.

    In the end, almost all of the draft pages were destroyed. Towards the end of Darwin’s life, his theory of evolution was more widely accepted and there was intense interest in the original draft of Origin of Species. Some were rescued from the piles of scrap paper and old notes and, over decades, many were given away as gifts especially by his children after his death. These draft pages are now dispersed around the world and some have probably been lost forever.

    Discovering Darwin’s manuscripts

    Today, the rough drafts of Darwin’s Origin of species are some of the most precious and valuable pieces of paper in the history of science worth almost a million dollars each. The last one to sell at auction, in 2018, went for £490,000 (approximately USD$ 600,000). The United Kingdom’s Minister for Arts, Heritage and Tourism placed an export bar on Darwin’s manuscript, due to its cultural and national significance, in hopes of keeping it in the country.

    So far, about 50 sheets were known to survive. This launch of the drafts by Darwin scholar, Dr John van Wyhe from the NUS Department of Biological Sciences, includes seven draft pages not found in previous lists with three draft pages recently rediscovered – bringing the total to 59. This collection of draft pages includes unprecedented details about each sheet and its history. For example, one was donated by Darwin’s daughter Henrietta Litchfield to a Red Cross auction during WWI for the war wounded. It was purchased anonymously by cotton merchant and aviation pioneer Sir Alfred Paton who donated it to his old school, Clifton College. It was later sold at auction in 1999 for £39,500 to an anonymous buyer “in the Americas” and has never been seen again. Fortunately, it was photocopied by Clifton College and a photograph was printed in the auction catalogue.

    Uncovering the mysteries behind Darwin’s drafts

    Darwin’s handwriting is notoriously difficult to read. All of the drafts have been transcribed and edited showing where the text appears in the published book so they may be compared. The drafts make it possible to see in detail how Darwin originally composed and revised many of his arguments. The drafts total 11,700 words (7.7% of Origin of species) and contain many sentences that were never published, offering fascinating insights into Darwin’s thinking as he composed the book that changed the world. What would have happened if he had published the original version of some of his arguments? In one crossed out sentence, Darwin wrote that “An instinct may almost be called an empty trick.”

    In a famous passage of the Origin of species, Darwin argued that natural selection could gradually transform an animal like a bear into something like a whale. He was mocked and criticised by reviewers so severely that he deleted the passage from all later editions. What would have happened if he had published the passage as originally written?

    In one of the drafts, this never-printed paragraph was revealed as follows:

    “In N. America a bear has been seen swimming for hours with widely open mouth, thus catching the minute crustaceans swimming on the surface. Even in so extreme a case as this, if the supply of minute crustaceans were constant, & there did not in the region exist better adapted competitors, I can see no difficulty in a race of Bears being rendered by natural selection more & more aquatic in habits & structure, with larger & larger mouth, till a creature was produced as monstrous in size & structure as a whale though feeding on prey so minute.”

    Darwin later made very extensive corrections to the first and second proofs which makes the text of the first draft differ even more from the published book. His son Francis recalled that “my mother looked over the proofs of the ‘Origin.’”

    The drafts can be viewed for free via a detailed illustrated introduction here. The link will be made live after the embargo is lifted.

    The drafts join the world’s largest collection of Darwin’s writings, both publications and handwritten manuscripts, Darwin Online.

    National University of Singapore (NUS)

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  • Skunks’ warning stripes less prominent where predators are sparse, study finds

    Skunks’ warning stripes less prominent where predators are sparse, study finds

    Newswise — Striped skunks are less likely to evolve with their famous and white markings where the threat of predation from mammals is low, scientists from the University of Bristol, Montana and Long Beach, California have discovered.

    Skunks’ iconic black and white colouration signals its toxic anal spray. However some skunks show very varied fur colour ranging from all black to thin or thick black and white bands to all white individuals. Variation is huge across the North American continent.

    Findings published today in Evolution, suggest that this is a result of relaxed selection, when environmental change eliminates or weakens the selection of a normally important trait – in this case black and white pelage.   

    Prof Tim Caro from Bristol’s School of Biological Sciences explained: “Warning coloration is an antipredator defence whereby a conspicuous signal advertises the ability of prey to escape predation, often because it is toxic or has spines or is pugnacious.”

    “Usually predators have to learn the significance of this signal and so it is predicted that warning colouration will look very similar across prey individuals of the same, as well as perhaps different, prey species to be an effective education tool. Yet some warningly coloured prey show rather different advertisements even within the same species.”

    Researcher Hannah Walker from the University of Montana documented the distribution of these different pelage colours across their range in North America using museum specimens. She plotted these against a menu of variables that the team thought might drive this variation in coloration.

    The team found that in locations in which skunks overlapped with rather few mammalian predators that might be capable of killing them, fur colour was varied even within the same litter.

    Where there were many species of predators that were a danger to them, they showed little variation.

    The team also examined owl and raptorial predators however while the effects were the same, they were not as evident. This is perhaps because birds have a poorer sense of smell and are less deterred by smelly anal defences. 

    “Our results indicate that relaxed predation pressure is key to warning signal variation in this species, whereas stronger pressure leads to signal conformity and stronger signals,” said Professor Caro.

    “We now know why not all skunks look alike, and perhaps why members of other warningly coloured species look different from each other.”

    Now the team plan to see if this occurs across other skunk species whose geographic ranges overlap in North America.

    Prof Caro concluded: “If relaxed selection operates within species, it should do so across prey species too. More broadly, this study provides another brick in the wall of explaining the evolution of coloration in nature.”

     

    Paper:

    ‘Predation risk drives aposematic signal conformity’ by Hannah Walker, Tim Caro et al in Evolution. 

    University of Bristol

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  • Research reveals Cerrado plants employ multiple strategies for surviving fires.

    Research reveals Cerrado plants employ multiple strategies for surviving fires.

    Newswise — In an article published in the journal Flora, researchers at São Paulo State University (UNESP) in Brazil examine some of the strategies developed over eons of evolution by plants in the Cerrado, Brazil’s savanna-like biome, to protect themselves and resprout quickly after fire.

    The article is commended by the journal as Highlighted Student Research. Its first author, Marco Antonio Chiminazzo, a PhD candidate at UNESP in Rio Claro, received funding from FAPESP for his master’s (19/21300-6) and PhD research (21/09269-9).  

    The co-authors are Alessandra Fidelis, a professor in the Department of Biodiversity at the Rio Claro Institute of Biosciences (IBRC-UNESP); Aline Bombo, a postdoctoral fellow at the same institution, and Tristan Charles-Dominique, a researcher at the Paris Sorbonne and Montpellier University in France. All three are Chiminazzo’s thesis advisors.

    “Fire plays an important role in the history of the Cerrado’s savanna-type vegetation. To survive fires, these plants have developed various strategies, which the different lineages have refined during a long evolutionary process,” Chiminazzo said. “We’ve known since we began studying the biome that the Cerrado’s plants have thick bark to protect their internal tissues. They also have a wide array of below-ground organs that enable them to resprout because they’re protected by being under the surface. However, these two strategies require plants to deploy a lot of resources. Our key question was whether they could do both at the same time – whether typical species of the Cerrado with below-ground organs were also able to produce significant amounts of above-ground bark.”

    The researchers also set out to discover whether there were differences between clonal and non-clonal species in terms of bark production and bud protection and whether maximum height correlated with the ability to propagate clonally, given that clonal plants are generally smaller because their resources must be used to fuel both vertical and lateral growth.

    “The first step was a review of the literature to identify woody species in the Cerrado whose below-ground organs and above-ground bark production rates had been described. We then went out into the field to dig and collect plants in areas of grassland with scattered shrubs [campo sujo] and dense woodland or shrubland [cerrado sensu stricto] in order to analyze their organs,” Chiminazzo said. The field trips were to the Santa Bárbara Ecological Station, an environmental protection unit in Águas de Santa Bárbara, São Paulo state.

    “We grouped the species on the basis of clonality or non-clonality and of types of below-ground organ, especially woody rhizomes, which promote clonal growth, or xylopodia and root crowns, which do not,” he said.

    By comparing below-ground organs and bark production rates, the authors of the study were able to show that plant species in the Cerrado can produce large amounts of bark (up to 0.9 millimeters per unit of growth) and at the same time develop below-ground organs that specialize in resprouting. In other words, they can protect themselves from fire by hiding a large proportion of their biomass below ground. 

    “We also found a clear division between clonal species and species that occupy the same space throughout their life cycle [in a phenomenon termed on-spot persistence]. Specifically, clonal species with woody rhizomes tend to produce more bark, protect themselves better and grow taller than species with xylopodia and root crowns,” he said. 

    These differences suggest that the plants have evolved two distinct strategies for resprouting from underground buds: clonal growth associated with a considerable effort to protect aerial branches; and on-spot persistence, possibly linked to a stronger focus on protecting buds in organs below ground. 

    “The findings show that plants in the Cerrado are capable of investing in different strategies to protect themselves against fire,” Bombo said. “The usual view is that that they invest either in above- or below-ground strategies. The ability to invest in both reflects the extent to which woody plants have adapted to fire in the Cerrado. Having both aerial and underground fire-related strategies for regeneration and persistence enables these species to survive fire events of varying intensities.”

    Next steps include examining which fire regimes favor regeneration and persistence strategies that are aerial, underground or a combination of both. “This can help us understand better the differences between above- and below-ground carbon stocks in the Cerrado,” Bombo said. “Furthermore, a comparison with different savannas around the world will show whether the results of this study might also apply to other types of vegetation exposed to fire events.”

    The study was also funded via two other projects (17/02934-1 and 15/06743-0). 

    Threatened biome 

    The Cerrado is now the most threatened of Brazil’s biomes. Deforestation in the Amazon has decreased significantly in 2023, while destruction of native vegetation in the Cerrado has risen to record levels. In the first five months of the year, it increased 35% compared with January-May 2022. The increase corresponded to 3,532 square kilometers of destruction. These numbers, which come from the National Space Research Institute (INPE), are highly alarming because the Cerrado is the world’s most biodiverse savanna, contains 33% of Brazil’s biodiversity, and is the birthplace of the three largest river basins in South America.

    As the destruction advances, important scientific research has been conducted to predict and prevent fire propagation (read more at: agencia.fapesp.br/44694) or use fire as a land management and conservation strategy (read more at: agencia.fapesp.br/26064). Other studies have also highlighted the extraordinary resilience and regenerative power of Cerrado plant species, which have evolved over millions of years in the presence of fire (read more at: agencia.fapesp.br/41100).  

    Sao Paulo Research Foundation (FAPESP)

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  • Does urbanization drive plant evolution?

    Does urbanization drive plant evolution?

    Newswise — Urbanization and human activities have transformed a significant proportion of the land on Earth, resulting in the formation of urban environments. These urban environments are man-made habitats that often impose several selective pressures on their inhabitants. A key characteristic of such environments is the presence of impermeable, heat-retaining surfaces created using brick, stone, asphalt, and concrete. Notably, these surfaces form urban heat islands, i.e., regions with elevated surface temperatures. An unexpected result of heat stress is the impact on the behavior, physiology, and evolutionary trajectories of resident organisms. Although several studies have investigated the role of urban heat stress on evolution in animals, its effects on plant evolution remain largely unexplored.

    To address this gap, a team of researchers led by Associate Professor Yuya Fukano from the Graduate School of Horticulture, Chiba University, Japan, investigated how urban heat islands affect the leaf colors of Oxalis corniculata, also known as the creeping woodsorrel. This plant exhibits diverse leaf colors ranging from green to red and is found in both urban and non-urban spaces across the world. Research suggests that these color variations serve as an evolutionary adaptation to protect the plant from environmental stress. Moreover, red pigments (anthocyanins) in the leaves are thought to mitigate heat and light-induced damage by intercepting light and forming antioxidants.

    To investigate this evolutionary theory, Dr. Yuya Fukano and his team, comprising Dr. Wataru Yamori from the University of Tokyo, Dr. Yuuya Tachiki from Tokyo Metropolitan University, and Dr. Kenta Shirasawa from the Kazusa DNA Research Institute, conducted field observations of the leaf color distribution in the creeping woodsorrel, across urban and non-urban regions at the local, landscape, and the global scales. Their study findings were published in Science Advances on [date].  “We noticed that the red-leaved variants of the creeping woodsorrel commonly grew near impervious surfaces in urban areas but rarely grew in farmlands or green spaces in and around the city,” says Dr. Fukano, while discussing their observations. The team identified a pattern where green-leaved variants of the creeping woodsorrel dominated green spaces while their red-leaf counterparts dominated the urban sites of Tokyo at both the local and landscape levels. Upon further examination of an online database, the team discovered that these geographical findings were consistent across the globe, thereby confirming a link between urbanization and leaf color variations in the creeping woodsorrel.

    This motivated the team to quantify the adaptive benefits of these leaf color variations by examining their influence over biomass growth and photosynthetic ability under heat stress and non-heat stress conditions across controlled and uncontrolled cultivation experiments.

    Through these experiments, the team found that the red-leaf variants exhibited superior growth rates and higher photosynthetic efficiency under high temperatures, whereas green-leaf variants thrived in lower temperatures. As a result, red-leaf variants tend to thrive in urban areas with low plant density due to high stress tolerance. The opposite is true for their green-leaf counterparts, which display higher growth competitiveness in lush green areas. “Although these findings will not change much in the immediate future, this study showcases one of the most popular examples of ongoing evolution that can be observed in urban areas,” remarks Dr. Fukano.

    The team also conducted genome-wide genetic analyses, which indicated that the red-leaf variant of O. corniculata may have evolved multiple times from the ancestral green-leaf plant. Discussing the implications of these findings, Dr. Fukano mentions, “Urban heat islands are precursors to global warming. Understanding the rapid adaptive evolution of urban organisms to high temperatures will provide valuable insights on ecosystem dynamics and sustainable crop production.”

    These adaptations to high-temperature stress likely extend beyond leaf color, thereby warranting further research into various plant traits for a comprehensive understanding of plant adaptation to urban heat islands.

    Chiba University

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  • Human-Driven Extinction Erasing Life’s Branches

    Human-Driven Extinction Erasing Life’s Branches

    Newswise — The passenger pigeon. The Tasmanian tiger. The Baiji, or Yangtze river dolphin. These rank among the best-known recent victims of what many scientists have declared the sixth mass extinction, as human actions are wiping out vertebrate animal species hundreds of times faster than they would otherwise disappear.

    Yet, a recent analysis from Stanford University and the National Autonomous University of Mexico, published this week in the Proceedings of the National Academy of Sciences, shows the crisis may run even deeper. Each of the three species above was also the last member of its genus, the higher category into which taxonomists sort species. And they aren’t alone.

    Up to now, public and scientific interest has focused on extinctions of species. But in their new study, Gerardo Ceballos, senior researcher at the Institute of Ecology at the National Autonomous University of Mexico, and Paul Ehrlich, Bing Professor of Population Studies, Emeritus, in the Stanford School of Humanities and Sciences, have found that entire genera (the plural of “genus”) are vanishing as well, in what they call a “mutilation of the tree of life.”

    “In the long term, we’re putting a big dent in the evolution of life on the planet,” Ceballos said. “But also, in this century, what we’re doing to the tree of life will cause a lot of suffering for humanity.”

    “What we’re losing are our only known living companions in the entire universe,” said Ehrlich, who is also a senior fellow, emeritus, by courtesy, at the Stanford Woods Institute for the Environment.

    A ‘biological annihilation’

    Information on species’ conservation statuses from the International Union for the Conservation of Nature, Birdlife International, and other databases has improved in recent years, which allowed Ceballos and Ehrlich to assess extinction at the genus level. Drawing from those sources, the duo examined 5,400 genera of land-dwelling vertebrate animals, encompassing 34,600 species.

    Seventy-three genera of land-dwelling vertebrates, Ceballos and Ehrlich found, have gone extinct since 1500 AD. Birds suffered the heaviest losses with 44 genus extinctions, followed in order by mammals, amphibians, and reptiles.

    Based on the historic genus extinction rate among mammals – estimated for the authors by Anthony Barnosky, professor emeritus of integrative biology at UC Berkeley – the current rate of vertebrate genus extinction exceeds that of the last million years by 35 times. This means that, without human influence, Earth would likely have lost only two genera during that time. In five centuries, human actions have triggered a surge of genus extinctions that would otherwise have taken 18,000 years to accumulate – what the paper calls a “biological annihilation.”

    “As scientists, we have to be careful not to be alarmist,” Ceballos acknowledged – but the gravity of the findings in this case, he explained, called for more powerful language than usual. “We would be unethical not to explain the magnitude of the problem, since we and other scientists are alarmed.”

    Next-level loss, next-level consequences

    On many levels, genus extinctions hit harder than species extinctions.

    When a species dies out, Ceballos explained, other species in its genus can often fill at least part of its role in the ecosystem. And because those species carry much of their extinct cousin’s genetic material, they also retain much of its evolutionary potential. Pictured in terms of the tree of life, if a single “twig” (a species) falls off, nearby twigs can branch out relatively quickly, filling the gap much as the original twig would have. In this case, the diversity of species on the planet remains more or less stable.

    But when entire “branches” (genera) fall off, it leaves a huge hole in the canopy – a loss of biodiversity that can take tens of millions of years to “regrow” through the evolutionary process of speciation. Humanity cannot wait that long for its life-support systems to recover, Ceballos said, given how much the stability of our civilization hinges on the services Earth’s biodiversity provides.

    Take the increasing prevalence of Lyme disease: white-footed mice, the primary carriers of the disease, used to compete with passenger pigeons for foods, like acorns. With the pigeons gone and predators like wolves and cougars on the decline, mouse populations have boomed – and with them, human cases of Lyme disease.

    This example involves the disappearance of just one genus. A mass extinction of genera could mean a proportional explosion of disasters for humanity.

    It also means a loss of knowledge. Ceballos and Ehrlich point to the gastric brooding frog, also the final member of an extinct genus. Females would swallow their own fertilized eggs and raise tadpoles in their stomachs, while “turning off” their stomach acid. These frogs might have provided a model for studying human diseases like acid reflux, which can raise the risk of esophageal cancer – but now they’re gone.

    Loss of genera could also exacerbate the worsening climate crisis. “Climate disruption is accelerating extinction, and extinction is interacting with the climate, because the nature of the plants, animals, and microbes on the planet is one of the big determinants of what kind of climate we have,” Ehrlich pointed out.

    A crucial, and still absent, response

    To prevent further extinctions and resulting societal crises, Ceballos and Ehrlich are calling for immediate political, economic, and social action on unprecedented scales.

    Increased conservation efforts should prioritize the tropics, they noted, since tropical regions have the highest concentration of both genus extinctions and genera with only one remaining species. The pair also called for increased public awareness of the extinction crisis, especially given how deeply it intersects with the more-publicized climate crisis.

    “The size and growth of the human population, the increasing scale of its consumption, and the fact that the consumption is very inequitable are all major parts of the problem,” the authors said.

    “The idea that you can continue those things and save biodiversity is insane,” Ehrlich added. “It’s like sitting on a limb and sawing it off at the same time.”

     

    Paul Ehrlich is also president of the Center for Conservation Biology at Stanford.

    Stanford University

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  • Order sets humans apart from animals

    Order sets humans apart from animals

    Newswise — Remembering the order of information is central for a person when participating in conversations, planning everyday life, or undergoing an education. A new study, published in the scientific journal PLoS One, shows that this ability is probably human unique. Even the closest relatives of humans, such as bonobos, do not learn order in the same way.

    “The study contributes another piece of the puzzle to the question of how the mental abilities of humans and other animals differ, and why only humans speak languages, plan space travel, and have learned to exploit the earth so efficiently that we now pose a serious threat to countless other life forms”, says Johan Lind, associate professor in ethology and deputy director at the Center for Cultural Evolution, Stockholm University. Since September also associate professor of ethology at Linköping University.

    Already earlier research at Stockholm University has suggested that only humans have the ability to recognize and remember so-called sequential information, and that this ability is a fundamental building block underlying unique human cultural abilities. But previously, this sequence memory-hypothesis has not been tested in humans’ closest relatives, the great apes. The new experiments now show that also bonobos, one of the great apes, struggle to learn the order of stimuli.

    In the recently published book The Human Evolutionary Transition: From Animal Intelligence to Culture (Princeton University Press), ethologists Magnus Enquist and Johan Lind at Stockholm University, and Stefano Ghirlanda, researcher in psychology at Brooklyn College, New York, have launched a new theory for how humans became cultural beings. A central idea concerns the difference in how humans and other animals recognize and remember sequential information.

    “We have previously analyzed a large number of studies that suggest that only humans recognize and remember sequential information faithfully. But, even though we analyzed data from a number of mammals and birds, including monkeys, there has been a lack of information from our closest relatives, the other great apes”, says Johan Lind.

    In a series of experiments, memory abilities of bonobos and humans were tested by having them press computer screens to, among other things, learn to distinguish between short sequences, including pressing right if a yellow square comes before a blue square, or by pressing to the left of the blue square appears before the yellow square.

    “The study shows that bonobos forget that they have seen a blue square already five to 10 seconds after it has disappeared from the screen, and that they have great difficulty learning to distinguish the sequences blue-square-before-yellow-square from yellow-square- before-blue-square, even though they have been trained for thousands of trials”, says Vera Vinken, associated with Stockholm University, now a PhD student in Great Britain at the Biosciences Institute, Newcastle University.

    In contrast, the study shows that humans learned to distinguish the short sequences nearly immediately. However, it still remains to be shown exactly how our closest relatives can remember and use sequential information.

    “We now know that our closest relatives do not share the same sequential mental abilities with humans. But even if the results indicate that their working memory works in principle in the same way as in rats and pigeons, no one has yet demonstrated this in practice”, says Magnus Enquist, professor emeritus and one of the founders of the Center for Cultural Evolution.

    The new results provide further support for the sequence memory-hypothesis, that during human prehistory an ability to remember and process sequences evolved, a necessary mechanism for many uniquely human phenomena such as language, planning ability and sequential thinking.

    Stockholm University

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  • Prehistoric Women’s Use of Atlatl Weapons Balanced Division of Labor in Hunting

    Prehistoric Women’s Use of Atlatl Weapons Balanced Division of Labor in Hunting

    Newswise — A new study led by Archaeologist Michelle Bebber, Ph.D., an assistant professor in Kent State University’s Department of Anthropology, has demonstrated that the atlatl (i.e. spear thrower) functions as an “equalizer”, a finding which supports women’s potential active role as prehistoric hunters.

    Bebber co-authored an article “Atlatl use equalizes female and male projectile weapon velocity” which was published in the journal Nature: Scientific Reports. Her co-authors include Metin I. Eren and Dexter Zirkle (a recent Ph.D. graduate) also in the Department of Anthropology at Kent State, Briggs Buchanan of University of Tulsa, and Robert Walker of the University of Missouri.

    The atlatl is a handheld, rod-shaped device that employs leverage to launch a dart, and represents a major human technological innovation used in hunting and warfare since the Stone Age. The first javelins are at least hundreds of thousands of years old; the first atlatls are likely at least tens of thousands of years old.

    “One hypothesis for forager atlatl adoption over its presumed predecessor, the thrown javelin, is that a diverse array of people could achieve equal performance results, thereby facilitating inclusive participation of more people in hunting activities,” Bebber said.

    Bebber’s study tested this hypothesis via a systematic assessment of 2,160 weapon launch events by 108 people, all novices, (many of which were Kent State students) who used both javelins and atlatls. The results are consistent with the “atlatl equalizer hypothesis”, showing that the atlatl not only increases the velocity of projectile weapons relative to thrown javelins, but that the atlatl equalizes the velocity of female- and male-launched projectiles.

    “This result indicates that a javelin to atlatl transition would have promoted a unification, rather than division, of labor,” Bebber said. “Our results suggest that female and male interments with atlatl weaponry should be interpreted similarly, and in some archaeological contexts females could have been the atlatl’s inventor.”

    “Many people tend to view women in the past as passive and that only males were hunters, but increasingly that does not seem to be the case,” Bebber said. “Indeed, and perhaps most importantly, there seems to be a growing consilience among different fields – archaeology, ethnography, and now modern experiments – that women were likely active and successful hunters of game, big and small.”

    Since 2019, every semester Bebber takes her class outside to use the atlatl. She noticed that females picked it up very easily and could launch darts as far as the males with little effort.

    “Often males became frustrated because they were trying too hard and attempting to use their strength to launch the darts,” Bebber said. “However, since the atlatl functions as a simple lever, it reduces the advantage of male’s generally greater muscle strength”.

    “Given that females appear to benefit the most from atlatl use, it is certainly within the realm of possibility that in some contexts females invented the atlatl,” Bebber said. “Likewise, in some primate species, females invent tool technologies for hunting as documented amongst the Fongoli chimpanzees.”

    To learn more about the Experimental Archaeology Lab at Kent State, visit: https://www.kent.edu/anthropology/experimental-archaeology-laboratory

    # # #

    Kent State University

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  • Poaching Risks Kordofan Giraffe Extinction in 15 Years

    Poaching Risks Kordofan Giraffe Extinction in 15 Years

    Newswise — Poaching of two Critically Endangered Kordofan giraffes per year could result in extinction in just 15 years within Cameroon’s Bénoué National Park without intervention. These are the alarming new findings of a University of Bristol and Bristol Zoological Society-led study published in the African Journal of Ecology.

    One of the last populations of Kordofan giraffes roam Cameroon’s Bénoué National Park in Africa with current estimates indicating there are fewer than 50 individuals left in the park. Bristol Zoological Society have been working to conserve this highly-threatened mammal since 2017.

    While poaching is frequently cited as a cause of population decline, evidence remains mostly anecdotal, with little research into its overall impact. Illegal hunters kill giraffes for their meat but also for their pelts, bones, hair and tails which are highly valued by some cultures.

    Researchers from Bristol Vet School and Bristol Zoological Society sought to analyse the effectiveness of different conservation measure interventions using a population modelling technique. The team compared anti-poaching interventions, population supplementation, and habitat protection. Each intervention was simulated individually and in combination to investigate their relative impact on population viability.

    Their modelling found the removal of one male and one female giraffe every year would result in an average time to extinction of just 15.3 years. The poaching of female giraffes had a more significant impact on population viability than males.

    The team’s findings confirm that conservation management should prioritise strengthening existing anti-poaching activity in conjunction with protecting wildlife corridors to aid dispersal.

    Kane Colston, the study’s lead author, who undertook the study as part of his Master’s degree at Bristol Vet School in conjunction with teaching partners Bristol Zoological Society, said: “Our findings confirm anti-poaching measures appear the most significant for population viability. The extent of poaching in Bénoué National Park is still unclear as far higher giraffe poaching rates have been reported in other national parks, but recent confirmed reports of the poaching of two giraffes in a period of just three months highlight the urgency of conservation intervention.”

    Dr Sam Penny, the project lead from Bristol Zoological Society, added: “These findings really underscore the magnitude of the threat facing Bénoué National Park’s Kordofan giraffe and highlight the importance of our conservation work in the area. We will continue to work with the park’s Conservation Service and our partner NGO Sekakoh to ensure anti-poaching initiatives are prioritised within the landscape.”

    Ends

    University of Bristol

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  • Memory and Learning Genes Date Back 650 Million Years: Study

    Memory and Learning Genes Date Back 650 Million Years: Study

    Newswise — A team of scientists led by researchers from the University of Leicester have discovered that the genes required for learning, memory, aggression and other complex behaviours originated around 650 million years ago.

    The findings led by Dr Roberto Feuda, from the Neurogenetic group in the Department of Genetics and Genome Biology and other colleagues from the University of Leicester and the University of Fribourg (Switzerland), have now been published in Nature Communications.

    Dr Feuda said: “We’ve known for a long time that monoamines like serotonin, dopamine and adrenaline act as neuromodulators in the nervous system, playing a role in complex behaviour and functions like learning and memory, as well as processes such as sleep and feeding.

    “However, less certain was the origin of the genes required for the production, detection, and degradation of these monoamines. Using the computational methods, we reconstructed the evolutionary history of these genes and show that most of the genes involved in monoamine production, modulation, and reception originated in the bilaterian stem group.

    “This finding has profound implications on the evolutionary origin of complex behaviours such as those modulated by monoamines we observe in humans and other animals.”

    The authors suggest that this new way to modulate neuronal circuits might have played a role in the Cambrian Explosion – known as the Big Bang – which gave rise to the largest diversification of life for most major animal groups alive today by providing flexibility of the neural circuits to facilitate the interaction with the environment.

    Dr Feuda added: “This discovery will open new important research avenues that will clarify the origin of complex behaviours and if the same neurons modulate reward, addiction, aggression, feeding, and sleep.”

    University of Leicester

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  • Exotic Remote Flora

    Exotic Remote Flora

    Newswise — Oceanic islands provide useful models for ecology, biogeography and evolutionary research. Many ground-breaking findings – including Darwin’s theory of evolution – have emerged from the study of species on islands and their interplay with their living and non-living environment. Now, an international research team led by the University of Göttingen has investigated the flora of the Canary Island of Tenerife. The results were surprising: the island’s plant-life exhibits a remarkable diversity of forms. But the plants differ little from mainland plants in functional terms. However, unlike the flora of the mainland, the flora of Tenerife is dominated by slow-growing, woody shrubs with a “low-risk” life strategy. The results were published in Nature.

    The researchers investigated how the plants of Tenerife differ in functional terms from plants from other parts of the world. They conducted extensive field research and measurements at over 500 sites using the most up-to-date methods of functional ecology. The sites were scattered all over the island at altitudes ranging from sea level to mountainous regions above 3,300 metres. The scientists recorded about 80% of Tenerife’s native seed plants, and surveyed eight plant characteristics: plant size, specific wood density, leaf thickness, absolute and specific leaf area, leaf dry matter, nitrogen concentration in leaf tissue, and seed weight. They compared their data with data on more than 2,000 plant species found on the mainland.

    “Our study shows, for the first time and contrary to all expectations, that species groups that evolved on the Canary Islands do not contribute to the expansion of the breadth of different traits. This means they do not lead to more functional diversity,” explains the lead of the study, Professor Holger Kreft, and Göttingen University’s Biodiversity, Macroecology and Biogeography research group. Previous comparisons show that species occurring on islands can differ significantly from their relatives on the mainland. A well-known example is provided by the Galapagos giant tortoise: the species is only found on the Galapagos Islands and, as a result of adaptation to its environmental conditions, is much larger than tortoises from the mainland. The research team expected similar differences between island and mainland plants, but this was not the case. “Rather, we see that most species follow the constraints of the island climate. Thus, medium-sized, woody species develop. These tend to live with the limited resources and high risks of extinction on the island. That is, they grow slowly. The high functional diversity is mainly due to the species that are widespread on the island and the nearby mainland,” explains Kreft.

    “At the beginning of our research, we assumed that island plants would show fundamental differences and would be characterised by rather limited diversity in terms of function due to their geographical isolation,” explains first author Dr Paola Barajas Barbosa. The results are part of her doctoral thesis, which she did at the University of Göttingen. She now does research at the German Centre for Integrative Biodiversity Research in Leipzig (iDiv). “We were all the more surprised to find that the plants of Tenerife have a comparatively high functional diversity.”

     

    Original publication: Martha Paola Barajas Barbosa et al. Assembly of functional diversity in an oceanic island flora. Nature (2023). DOI: 10.1038/s41586-023-06305-z

    University of Gottingen

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  • Virginia Tech researcher discovers new millipede species in the Los Angeles metropolis

    Virginia Tech researcher discovers new millipede species in the Los Angeles metropolis

    Newswise — In busy Los Angeles, few people pay attention to what’s under their feet, but a new underground movement has people looking at the subterranean world just below the surface. A team of scientists discovered a new species of millipede crawling just beneath the soil surface in Los Angeles and Orange counties.

    These never-before-seen creatures are pale, blind, thin, inch-long burrowers with the ability to produce a silk-like sticky substance, similar to spider silk. Measuring in at 0.5 millimeters wide and 2 1/2 centimeters long, these creatures are about the width of the a thin graphite lead of a mechanical pencil and about as long as a small paperclip.

    Despite being so small, they are described as having a gaping toothy mouth and over 480 legs. The species in question is called the Los Angeles Thread Millipede, formally named Illacme socal.

    Paul Marek, associate professor in the Department of Entomology in the College of Agriculture and Life Sciences at Virginia Tech, was the lead author of the study that described the new millipede.

    “We hope that this discovery will encourage conservation efforts to protect these unique creatures and their habitats,” said Marek. “The discovery of Illacme socal highlights the importance of research into subterranean fauna.”

    The discovery of Illacme socal was made possible by funding from the National Science Foundation. The research team included scientists from Virginia Tech, West Virginia University, and the University of California, Berkeley. The findings were published in the journal ZooKeys.

    The team captured a video of the millipede burrowing and moving through small spaces and crevices underground. This is the first-ever video of this species in action and provides insight into the unique behaviors of these fascinating creatures. 

    This research discovery highlights the importance of habitat preservation efforts to protect the environment and prevent the loss of biodiversity. The millipede was found in two parks in the Los Angeles and Orange counties but almost certainly lived in other parts of the metropolis in the past.

    The fact that populations of this species is living in two small well-known areas that are near constant development emphasizes the need for conservation efforts to protect this and other threatened organisms.  

    Virginia Tech

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  • Sea snake vision evolved to regain colour

    Sea snake vision evolved to regain colour

    Newswise — An international team of scientists examining the genetic history of sea snakes have found that the species has enhanced their colour vision in response to living in brighter and more colourful marine environments.

    “Our research has found that the annulated sea snake possesses four intact copies of the opsin gene SWS1,” said PhD candidate Isaac Rossetto, from the University of Adelaide’s School of Biological Sciences who led the study.

    “Two of these genes have the ancestral ultraviolet sensitivity, and two have evolved a new sensitivity to the longer wavelengths that dominate ocean habitats.

    “The earliest snakes lost much of their ability to see colour due to their dim-light burrowing lifestyle.

    “However, their sea snake descendants now occupy brighter and more spectrally complex marine environments. We believe that recent gene duplications have dramatically expanded the range of colours sea snakes can see.”

    The team examined published reference genomes to examine visual opsin genes across five ecologically distinct species of elapid snakes. They looked at the gene data of Hydrophis cyanocinctus, or the annulated sea snake, a species of venomous snake found in tropical and subtropical regions of Australia and Asia.

    The team included scientists from The University of Adelaide, The University of Plymouth and The Vietnamese Academy of Science and Technology. They published their findings in the journal Genome Biology and Evolution.

    Many animals have lost opsins throughout their genealogical history as they’ve adapted to new habitats, but it is very rare to see opsin gains.

    “Humans have a similarly expanded sensitivity to colours, while cats and dogs are partially colour-blind much like those early snakes,” said Mr Rossetto.

    “It’s quite unique and interesting that these snakes appear to be gaining and diversifying their opsins, when other land-to-sea transitioned animals have done the opposite.”

    “Basically, there’s only one other case within reptiles at all where we think this has happened.”

    Newly gained colour-vision opsins have also been recorded in the semi-aquatic Helicops snake.

    Evidence of colour vision in Hydrophis snakes was first published in 2020, but this new research shows it is the result of gene duplication rather than gene polymorphism. This means expanded colour vision is more common among the species than first thought.

    “With a polymorphism, it’s a bit of a lottery – only some individuals would have that extended colour sensitivity. But now we know that there are multiple gene copies which have diverged, so colour vision is expected to be seen in all members of these species,” said Mr Rossetto.

    University of Adelaide

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  • Serious monkey business: chimpanzee heart check via digital camera

    Serious monkey business: chimpanzee heart check via digital camera

    Newswise — A world-first experiment to measure chimpanzee heart rates via a digital camera could help curb cardiovascular disease in great apes in captivity and provide valuable insights into how their brain develops from an early age.

    Using a contact-free technique to extract cardiac signals from chimpanzees by filming subtle movements in their face or thorax, and monitoring their emotional response to different stimuli, a team of researchers led by the University of South Australia (UniSA) has made some startling discoveries.

    Chimpanzees – our closest living relatives – show similar responses to human babies when they experience fear, excitement, or joy, causing their heart rate to increase or decrease.

    Their response to videos of nature scenes is also the same as humans, relaxing them and lowering their heart rate significantly, despite not being familiar with the environment.

    By monitoring their heart rates from a distance, researchers are confident they can pinpoint early signs of cardiac disease in chimpanzees – one of the main causes of mortality in captive great apes – and flag these endangered animals for treatment.

    Seven chimpanzees were filmed in captivity from a short distance at the Wolfgang Koehler Primate Research Centre in Leipzig, Germany, for the study. UniSA engineers were sent the footage and used artificial intelligence to determine the heart rates.

    Remote sensing engineer UniSA Professor Javaan Chahl says it is the first time that chimpanzee heart rates have been recorded by a digital camera, extracting cardiac signals from their facial hues using image-processing algorithms.

    Previous studies have either relied on sensors attached to the chimpanzee’s body, requiring primates in captivity to be trained to tolerate them, or ensuring the animal is anaesthetised before undertaking basic health checks.

    The researchers not only recorded chimpanzee heart rates using the new technology, but also compared how the apes’ heart rates changed when shown videos of aggressive behaviour between chimpanzees from different groups, scenes of chimpanzees eating, and nature videos.

    Lead author, UniSA PhD student Danyi Wang, says the apes’ heart rate increased when viewing video footage of chimps fighting and feeding, and slowed when looking at nature scenes.

    “Heart rate changes can be linked to emotional responses, mental effort, attention and focus,” Danyi says. “Babies show emotional responses early in development, which can be observed by physiological changes that help them adapt and integrate into their environment. We observed the same in the chimpanzees we monitored.

    “Their responses to viewing nature scenes could be an innate physiological response to the natural world. We know that when humans spend time in nature, or view nature-related stimuli, it has a calming effect. It appears nature has the same effect on chimpanzees, and this could be deeply rooted in our evolutionary history.”

    Because primates have similar DNA to humans, monitoring their physiological changes may provide vital information about the development of their thinking, attention, language, learning, memory and perception.

    Prof Chahl says, as with human infants, heart rate measures could be used to test recognition memory and therefore help reveal mental processes in different contexts.

    “This would not only complement existing efforts to understand the evolution of cognition, but it would also enable us to test populations that otherwise do not engage in cognitive tasks, such as very young or untrained primates.”

    Cardiovascular disease is very common in captive great apes, typically due to age-related changes, thickening of the heart muscles and reduced elasticity. By monitoring their heart, researchers believe they will be able to detect abnormal heart rhythms and potential signs of cardiac disease earlier.

    “Our contact-free technique opens up new routes to study primates’ emotional and cognitive states and may also greatly enhance the health management of a wide range of animal species,” Prof Chahl says.

    The study is published in Behaviour Research Methods, one of the world’s leading journals in experimental psychology.

    University of South Australia

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  • Antarctic bacteria and computer calculations used to create new enzyme

    Antarctic bacteria and computer calculations used to create new enzyme

    Newswise — For the first time, researchers have succeeded in predicting how to change the optimum temperature of an enzyme using large computer calculations. A cold-adapted enzyme from an Antarctic bacterium was used as a basis. The study is to be published in the journal Science Advances and is a collaboration between researchers at Uppsala University and the University of Tromsø.

    The type of cold-adapted enzymes used by the researchers for their study can be found in bacteria and fish that live in icy water, for example. Evolution has shaped them to be able to function even at very low temperatures at which other enzymes are normally stone dead. These enzymes also always have a lower optimum temperature and melting point than enzymes from warm-blooded animals and organisms that live at higher temperatures.

    The researchers wondered whether computer simulations of the catalysed chemical reaction could predict a small number of mutations in the Antarctic enzyme that could result in an increase in its optimum temperature. The results of the calculation showed that this would be possible if 16 mutations were inserted from the corresponding pig enzyme into the bacterial variant.

    The researchers then produced this hybrid enzyme and measured its catalytic activity as a function of temperature, and it was indeed found that the new variant had a 6 °C higher optimum than the original variant and was faster than both the Antarctic and pig enzymes at 50 °C . They also solved the three-dimensional structure of the hybrid enzyme by X-ray crystallography and showed that the necessary structural changes predicted by the computer calculations had indeed taken place.

    Computer-based enzyme design has become a major and hotly pursued research area in recent years. The goal is to create enzymes with new properties and to do so with the help of computer calculations instead of labour-intensive experiments.

    “For example, this may involve creating new enzymes that catalyse chemical reactions not found in nature or changing their properties so that they can better cope with heat, cold, high pressure, increased salinity and so on. This area is therefore the subject of great biotechnological interest,” notes Johan Åqvist, Professor of Theoretical Chemistry at Uppsala University.

    https://www.science.org/doi/10.1126/sciadv.adi0963

    Uppsala University

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  • New Early Toothed Whale Species Found

    New Early Toothed Whale Species Found

    Newswise — Have you ever wondered what the earliest ancestors of today’s dolphins looked like? Then look no further, meet Olympicetus thalassodon, a new species of early odontocete, or toothed whale, that swam along the North Pacific coastline around 28 million years ago. This new species is one of several that are helping us understand the early history and diversification of modern dolphins, porpoises and other toothed whales. The new species is described in a new study published in the open access journal PeerJ Life and Environment by Puerto Rican paleontologist Jorge Velez-Juarbe of the Natural History Museum of Los Angeles County.

    “Olympicetus thalassodon and its close relatives show a combination of features that truly sets them apart from any other group of toothed whales. Some of these characteristics, like the multi-cusped teeth, symmetric skulls, and forward position of the nostrils makes them look more like an intermediate between archaic whales and the dolphins we are more familiar with,” says Dr. Velez-Juarbe, Associate Curator of Marine Mammals at NHMLAC. 

    But Olympicetus thalassodon was not alone, the remains of two other closely related odontocetes were described in the same paper. The fossils were all collected from a geologic unit called the Pysht Formation, exposed along the coast of the Olympic Peninsula in Washington State and dated to between 26.5–30.5 million years. 

    The study further revealed that Olympicetus and its close kin belonged to a family called Simocetidae, a group so far known only from the North Pacific and one of the earliest diverging groups of toothed whales. Simocetids formed part of an unusual fauna represented by fossils found in the Pysht Formation and which included plotopterids (an extinct group of flightless, penguin-like birds), the bizarre desmostylians, early relatives of seals and walruses, and toothed baleen whales.

    Differences in body size, teeth and other feeding-related structures suggest that simocetids showed different forms of prey acquisition and likely prey preferences. “The teeth of Olympicetus are truly weird, they are what we refer to as heterodont, meaning that they show differences along the toothrow”, notes Dr. Velez-Juarbe, “this stands out against the teeth of more advanced odontocetes whose teeth are simpler and tend to look nearly the same.”

    However, other aspects of the biology of these early toothed whales remain to be elucidated, such as whether they could echolocate like their living relatives, or not. Some aspects of their skull can be related to the presence of echolocating-related structures, such as a melon. An earlier study had suggested that neonatal individuals could not hear ultrasonic sounds, so the next step would be to investigate the earbones of subadult and adult individuals to test whether this changed as they grew older.  

     

    PeerJ

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  • Neanderthal cave engravings are oldest known – over 57,000 years old

    Neanderthal cave engravings are oldest known – over 57,000 years old

    Newswise — Markings on a cave wall in France are the oldest known engravings made by Neanderthals, according to a study published June 21, 2023 in the open-access journal PLOS ONE by Jean-Claude Marquet of the University of Tours, France and colleagues.

    Research in recent decades has revealed a great deal about the cultural complexity of Neanderthals. However, relatively little is known about their symbolic or artistic expression. Only a short list of symbolic productions are attributed to Neanderthals, and the interpretation of these is often the subject of debate. In this study, Marquet and colleagues identified markings on a cave wall in France as the oldest known Neanderthal engravings.

    The cave is La Roche-Cotard in the Centre-Val de Loire of France, where a series of non-figurative markings on the wall are interpreted as finger-flutings, marks made by human hands. The researchers made a plotting analysis and used photogrammetry to create 3D models of these markings, comparing them with known and experimental human markings. Based on the shape, spacing, and arrangement of these engravings, the team concluded that they are deliberate, organized and intentional shapes created by human hands.

    The team also dated cave sediments with optically-stimulated luminescence dating, determining that the cave became closed off by infilling sediment around 57,000 years ago, well before Homo sapiens became established in the region. This, combined with the fact that stone tools within the cave are only Mousterian, a technology associated with Neanderthals, is strong evidence that these engravings are the work of Neanderthals.

    Because these are non-figurative symbols, the intent behind them is unclear. They are, however, of a similar age with cave engravings made by Homo sapiens in other parts of the world. This adds to a growing body of evidence that the behavior and activities of Neanderthals were similarly complex and diverse as those of our own ancestors.

    The authors add: “Fifteen years after the resumption of excavations at the La Roche-Cotard site, the engravings have been dated to over 57,000 years ago and, thanks to stratigraphy, probably to around 75,000 years ago, making this the oldest decorated cave in France, if not Europe!”

     

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