Philippa Kaur

Download the Nature Podcast 13 March 2024 In this episode:00:45 Making a map of the human heartThe human heart consists of multiple, specialized structures that all work together to enable the organ to beat for a lifetime. But exactly which cells are present in each part of the heart has been difficult to ascertain. Now, a team has combined molecular techniques to create an atlas of the developing human heart at an individual cell level. Their atlas provides insights into how cell communities communicate and form different structures. They hope that this knowledge will ultimately help in the treatment of congenital heart conditions, often caused by irregular development of the heart.Research article: Farah et al. Nature video: Building a heart atlas08:37 Research HighlightsResidue in ceramic vases suggests that ancient Mesoamerican peoples consumed tobacco as a liquid, and a wireless way to charge quantum batteries.Research Highlight: Buried vases hint that ancient Americans might have drunk tobaccoResearch Highlight: A better way to charge a quantum battery11:11 The evolution of menopause in toothed whalesMenopause is a rare phenomenon, only known to occur in a few mammalian species. Several of these species are toothed whales, such as killer whales, beluga whales and narwhals. But why menopause evolved multiple times in toothed whales has been a long-standing research question. To answer it, a team examined the life history of whales with and without menopause and how this affected the number of offspring and ‘grandoffpsring’. Their results suggest that menopause allows older females to help younger generations in their families and improve their chances of survival.Research Article: Ellis et al.News and Views: Whales make waves in the quest to discover why menopause evolved18:03 Briefing ChatHow the new generation of anti-obesity drugs could help people with HIV, and the study linking microplastics lodged in a key blood vessel with serious health issues.Nature News: Blockbuster obesity drug leads to better health in people with HIVNature News: Landmark study links microplastics to serious health problemsSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.Never miss an episode. Subscribe to the Nature Podcast on Apple Podcasts, Google Podcasts, Spotify or your favourite podcast app. An RSS feed for the Nature Podcast is available too. More

Northern Australian elder George Milpurrurr shows the next generation how to do a cultural burn.Credit: Penny Tweedie/Alamy

Indigenous Australians have been using fire to shape the country’s northern ecosystems for at least 11,000 years, according to charcoal preserved in the sediment of a sinkhole. The study was published on 11 March in Nature Geoscience1.The practice of cultural burning, also known as ‘fire-stick farming’, is integral to Indigenous Australian culture and history, and is understood to have profoundly altered landscapes across the country.Fire-stick farming involves introducing frequent, low-intensity fires in small areas of the landscape in a patchy, ‘mosaic’ pattern, and is done early in the dry season. The practice is important culturally and environmentally; in particular, it reduces the amount of fuel available for burning and therefore decreases the intensity of wildfires that might spark late in the dry season because of lightning strikes or other triggers.Archaeological evidence indicates that humans have continuously occupied the Australian continent for at least 65,000 years2, but little is known about when the practice of fire-stick farming began.“You need a really long record that goes back before people were here so you can see what the natural world — the definitively unimpacted world, if you’d like — looks like and then you’ve got enough of a record to be able to see if anything changed,” says study co-author Michael Bird, a geologist at James Cook University in Cairns, Australia.The researchers found that record in the sediment of Girraween Lagoon, a permanent water body formed in a collapsed sinkhole near Darwin in the Northern Territory. The lagoon is an important site for the traditional owners of the land, the Larrakia Nation, and was made famous by the crocodile attack scene in the 1986 film Crocodile Dundee.Because the lagoon has remained full, its sediments offer a continuous record of deposition that has not been disturbed by drying out and cracking. Bird and his colleagues were able to extract a core from the bottom of the lagoon that provided a 150,000-year-long record of changes in the type and geochemistry of the deposited charcoal, and in the accumulation of pollen.Change in the charcoalThe team notes that, around 11,000 years ago, the changes in the charcoal deposits point to alterations in the intensity of fires in the area.Without human influence, fires are less frequent but have enough intensity to burn trees and leave behind charcoal, says Bird.“A less-intense fire doesn’t get into the crown — it’s burning what’s on the ground,” he says. The grass, as well as twigs and fallen tree leaves, are more likely to become charcoal than the trees themselves, he adds.Because tree-derived charcoal has higher concentrations of the isotope carbon-13 than does charcoal from grasses, the researchers analysed the composition and geochemistry of the burnt residue in the sample. The authors found a sustained change from low-frequency, high-intensity fires — the ‘natural’ fire regime — to more frequent but less intense ones, which they suggested was the result of Indigenous fire-stick farming.The authors ruled out climate change as the cause of the shift by using the ratio of tree pollen to grass pollen as a type of climate history to show that vegetation changes did not explain the shift in the charcoal record.However, Bird notes that European colonization has mostly brought an end to cultural burning practices, and has shifted fire intensity back towards a natural pattern. “Because we’ve had, 10,000 plus years of a particular fire regime, it’s the release from that fire regime that’s actually creating quite significant issues,” he says, suggesting that this shift has contributed to the return of more high-intensity wildfires.Joe Fontaine, a fire ecologist at Murdoch University in Perth, Australia, says that the growing understanding of how cultural burning has shaped the Australian landscape, particularly in the northern regions, is crucial for contemporary fire-management practices, which to a large extent have excluded Indigenous people and their expertise.“The barriers to doing cultural burning, in our arcane system of laws and bureaucracy,” are challenging to overcome, Fontaine says. There are also many more permanent structures in the landscape nowadays than there were before colonization, he says, so the challenge is to work out where and how cultural burning can be restored as a practice.The continuing work that “puts cultural burning practices out there and establishes it as something that really existed, is crucial to the evolution of contemporary fire management,” he says. More

For more than a decade, Christie Bahlai has been part of a long-running survey of ladybirds. Each summer, she and other scientists send students from their laboratories to a site on Gull Lake, Michigan, about 220 kilometres west of Detroit, to monitor 14 beetle species. Their goal: to track how invasive species are affecting native populations.The ladybird project has been running since 1989, and for 20 years had been directed by Douglas Landis, an entomologist at Michigan State University in East Lansing and Bahlai’s former postdoctoral adviser. But last year, Landis decided to retire. In December, he reached out to Bahlai, a computational ecologist at Kent State University in Ohio, to ask whether she wanted the many boxes of handwritten data sheets stored in his laboratory.
How to digitize your lab notebooks
Bahlai already had digital scans of the documents. Still, she wanted the originals. “What if there’s a note on the data that didn’t come through on the scans, or some other crucial context?” Bahlai explains. “And so, I received my inheritance over Christmas vacation.”Generally, “the easiest and most productive” way to compile data is to type them directly into a spreadsheet, says Miguel Acevedo, an ecologist at the University of Florida in Gainesville. But using a computer, tablet or even a smartphone in the field isn’t always practical. The Puerto Rican rainforest, where Acevedo studies malaria infection in lizards, is prone to unexpected downpours, so his team logs its data in pencil-drawn tables in waterproof notebooks. Bahlai and her colleagues record species counts by hand while working in dusty cornfields, their fingers often covered in sticky insect-trap goo.To be useful, handwritten data must be digitized into a form that can be analysed. But because this is one step removed from data collection, the process is rife with potential for error. Whether carrying over data manually or using software tools such as optical character recognition (OCR), researchers need to think about how to keep damage to a minimum. Here are five tips to do just that.Make a digitization integrity planOne of the first things Acevedo tells his students is that correcting mistakes in data becomes an order of magnitude more difficult with every step towards publication. He calls this the 1/10/100 rule: incorrectly writing down a lizard’s length in millimetres instead of centimetres is easily fixed — a metaphorical $1 mistake. But the cost jumps to $10 if the data point slips through the digitization process, and to $100 after it’s been analysed. Standardized protocols and workflows help to prevent such errors and minimize the cost, he says.In Bahlai’s lab, a “meticulous and reliable” student volunteer transfers the data from the original paper sheets to Google Docs. They annotate anything that they’re unsure of — a smudged number, for example — and tag Bahlai, who will take a closer look. After a second student double-checks the data, Bahlai transfers them into a spreadsheet, for more in-depth quality checks.Acevedo’s set-up is different: students work in pairs, with one reading out the data and the other typing them in. He also insists on including in each notebook a metadata page that contains acronym definitions, units of measurement and other elements. “If somebody is looking at notebooks 20 years from now,” he says, “they’ll know exactly what they’re looking at.”Here’s another must-do, says Joel Correia, a human–environment geographer at Colorado State University in Fort Collins: invest the time and resources upfront to train the people doing the fieldwork. Correia studies the social and ecological effects of long-term land-stewardship practices in three Indigenous nations in the Ecuadorian Amazon. His team teaches members of those communities social-science research methods, such as designing and conducting interviews and surveys in their local language. In such multilingual, multicultural contexts, he says, having shared clarity around the concepts underlying the research is crucial, especially when taking written field notes that will be translated and digitized.Back up your paper, ASAPOnce you’re back from the field, do some rough digitization as soon as you can, Correia advises. Scanning your notebooks to PDFs, or even photocopying them, will safeguard you from the pain of seeing stacks of interviews destroyed by rain, fire or other unforeseen events. “I have not had that experience, but I have certainly heard of other people who have,” he says.Use several pairs of eyesOne common way of reducing errors is by having a number of people input the same data, and then correcting inconsistencies between the versions. How many pairs of eyeballs do you need? Make it an experiment, suggests Acevedo: test your error rate with different numbers of double-checkers, and find the point of diminishing return.

For her research, climatologist Linden Ashcroft often has to digitize historical sources, such as this page of climate data from 1837.Image courtesy of the National Archives of Australia. NAA: PP430/1, VOLUME 4.

But don’t overlook the human element, says Linden Ashcroft, a climatologist at the University of Melbourne, Australia. Ashcroft has run community-science efforts to digitize hand-written records in farmers’ diaries and other historical sources, some going back 200 years. She says that the World Meteorological Organization recommends that such data be double- or triple-keyed — that is, input independently by two or three people. But she knows of projects involving as many as eight individuals. “Is that really a good use of people’s time?”A good rule of thumb, Ashcroft suggests, is to calibrate your error rate to your project goals. “If you’re doing a deep dive into the weather and climate of a particular place, you want to lovingly correct the data,” she says. But if your data will be just a few of a million entries in an international database that researchers use to predict weather patterns, a slightly higher error rate probably won’t affect the outcome.Home in on outliersIf you are working with numbers, you can program your software to flag outliers, improperly formatted values and seemingly illogical data. For instance, Acevedo recalls discovering that lizards measured in one year were an order of magnitude smaller than usual. “I was there, so I knew that the lizards were not particularly small.” After he examined the notebooks from that period, he saw in the metadata that the numbers were recorded in millimetres rather than centimetres, and corrected the data.But that approach doesn’t always work, Ashcroft cautions. Outliers in her data can reflect unusually heavy rain or aberrations in atmospheric conditions, such as temperature or air pressure — real variation that is simply unexpected. “You don’t want the statistical test to kick those [values] out, because extremes are how we’re going to be affected climate change,” she says.Try OCR (and other software)OCR software can be used to convert scanned images into machine-encoded text. Many such tools are available — and most of them can successfully capture data sets in which handwritten text and numbers are written clearly and do not bleed out of their designated columns.But off-the-shelf software often falls short when applied to historical handwriting, in which s’s might look like f’s, for example, says Stuart Middleton, a computer scientist at the University of Southampton, UK. It also performs poorly in the face of image noise, such as creases or shadows in a scanned image or text that spills over from one column of a table into another. In the documents he works with, he says, “there are all sorts of horrors going on.”
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In such cases, researchers with a bit of computer-science savvy can try using different OCR models. Those models — available on the open-source machine-learning platform Hugging Face, for instance — are generally pre-trained on a wide array of images, but feeding them training images that are similar to your data could improve their performance, says Middleton. Scientists with advanced skills in coding and artificial intelligence can also modify the networks to better fit their projects. Middleton’s team is developing more-advanced, multistep OCR solutions for working with historical weather data, including new ways of training, as well as image post-processing.Options exist for digitizing other data types, too. Eliza Grames, an integrative biologist at Binghamton University in New York, uses historical data — largely graphs and charts from studies in the late nineteenth and early twentieth centuries — to map long-term insect-population trends. A program called metaDigitise (and a similar, browser-based program, WebPlotDigitizer) allows her to redraw the plots and calculate the underlying data. She also uses Inkscape, an open-source alternative to Adobe Illustrator, to digitize old species range data into a format that is readable by geographic-information-system mapping software.OCR still requires extensive expert oversight to clean up irregularities and check for errors, Ashcroft warns. She prefers to harness the efforts of volunteers around the world. “To me, the historical weather observations are a really valuable opportunity to engage people with climate science in a fun and easy way,” she says. “People get to be a part of the story.”And OCR is not always worth the trouble. For smaller projects, scanning every page and checking for errors after processing it through software might not yet be more efficient than having students do the job by hand, Acevedo says. But at the rate software is advancing, he says, that could soon change. “Maybe if we have this talk in 2025.” More

Credit: Matt Mays/Mays Entertainment

In 1979, ethologist Christophe Boesch and his wife Hedwige Boesch-Achermann began researching the behaviour of a community of wild West African chimpanzees in Taï National Park, Côte d’Ivoire. Their study became the first long-term research on chimpanzees to be conducted in a continuous rainforest, rather than in a mixed savannah habitat such as Gombe National Park, Tanzania, where primatologist Jane Goodall had been working for almost two decades. It led to numerous discoveries about cultural diversity and behavioural variation — revealing, for example, that chimpanzees used hammers to crack nuts, that males cared altruistically for unrelated orphans and how predation by leopards influenced grouping patterns. Boesch argued that, because the Taï population was relatively undisturbed, it yielded a uniquely informative picture of chimpanzee behavioural adaptations. The Taï project remains the only study of a large population of habituated West African chimpanzees (Pan troglodytes verus), a rapidly dwindling subspecies (taichimpproject.org). He has died aged 72.Boesch promoted the conservation of chimpanzees by organizing population surveys, launching chimpanzee-research sites and driving the creation of national parks, including Moyen-Bafing National Park in Guinea. When faced with obstacles, from changing governments and obstructive mining companies to sceptical donor agencies, he had little patience for bureaucracy or unnecessary delays. He envisaged a continuous protected area that stretched from Senegal to Côte d’Ivoire and pursued this goal through the Wild Chimpanzee Foundation (WCF), which he and Boesch-Achermann co-founded in 2000. Under Boesch’s leadership, the WCF engaged local people and lobbied industries and ministries to avert threats from mining activities and infrastructural development. The foundation continues to lead conservation efforts in West Africa.Boesch was born in St Gallen, Switzerland, in 1951. When he was 12 years old, his father, a professor of cultural psychology, gave him King Solomon’s Ring by ethologist Konrad Lorenz, a 1949 book that stimulated Boesch’s lifelong interest in animal behaviour. He attended secondary school in Paris and returned to Switzerland to study biology at the University of Geneva. His first experience of field work with great apes was in Rwanda, studying mountain gorillas as an assistant to US primatologist Dian Fossey.
Chimpanzees are dying from our colds — these scientists are trying to save them
After learning that chimpanzees in Taï use natural hammers to crack open edible nuts, the Boesches spent five years habituating a wild community there to their presence, much of the time in the field spent together with their two young children. At first, the chimpanzees invariably fled, so that for many years the research was, in Boesch’s words, “a study of chimpanzee behinds”. Persistence paid off and led to a PhD from the University of Zurich, Switzerland, in 1984 and to an assistant professorship at the University of Basel in 1991.In 1997, Boesch became one of the founding directors of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. By then, research in Taï was producing rich data on three neighbouring communities, shedding light on intergroup dynamics and social traditions. In 1999, together with Andrew Whiten, Boesch organized a comparison of the behavioural diversity of seven chimpanzee populations. The resulting paper took the study of chimpanzee cultural variation to an increasingly systematic level and galvanized further work throughout Africa (A. Whiten et al. Nature 399, 682–685; 1999). Boesch set up an ambitious project to collect chimpanzee data from more than 50 sites in 18 countries. This project found evidence that chimpanzee cultural diversity had been reduced by human influences, suggesting that the conservation of these animals needs to include the protection of their local traditions.
These animals are racing towards extinction. A new home might be their last chance
Boesch thought that scientists routinely underestimated the cognitive complexity of chimpanzees, for example in their abilities to cooperate, teach their young or use several tool sets; and that studies of chimpanzees in captivity tended to have little relevance to understanding their behaviour in the wild. His pioneering findings often went against prevailing scientific thinking, but he trusted his eyes and never shied away from defending his views.By the 1990s, chimpanzees in Taï were dying from pathogens, such as anthrax, Ebola and respiratory viruses, that decimated Boesch’s study community and endangered human observers. Boesch introduced safety measures and organized studies that led to the first direct evidence of viruses being transmitted from humans to wild apes.In an era when painstaking fieldwork appealed less to students than did seemingly swifter rewards from laboratory experiments, Boesch insisted on the merits of old-fashioned patience: “Go to the field,” he would tell his students. “Observe the chimpanzees and don’t worry about the textbooks — the chimpanzees will teach you!”His passion and enthusiasm for chimpanzee research and conservation were contagious. And Boesch inspired a generation of primatologists. Inza Koné, president of the African Primatological Society, referred to Boesch as the father of primatology in Côte d’Ivoire, a characterization that could fairly be extended to West Africa as a whole. Early in Boesch’s career, he realized that each chimpanzee population is unique and that connecting separate populations is the key to their survival. His more than four decades of devotion to studying and protecting wild chimpanzees leaves a lasting impact on their survival and our knowledge of this species. More

RESEARCH HIGHLIGHT
28 February 2024

In a large US cohort of mother–child dyads, prenatal exposure to phthalate metabolites was associated with varying degrees of negative birth outcomes. More

Species extinctions are speeding up worldwide. Biodiversity monitoring and assessment must underpin efforts to tackle this crisis (E. Tekwa et al. Phil. Trans. R. Soc. B 378, 20220181; 2023). Yet expertise in taxonomy, the scientific basis for biodiversity research and management, has been in decline.
Competing Interests
The authors declare no competing interests. More

Download the 26 February long read podcastThe phenomenon of animals catching diseases from humans, called reverse zoonoses, has had a severe impact on great ape populations, often representing a bigger threat than habitat loss or poaching.However, while many scientists and conservationists agree that human diseases pose one of the greatest risks to great apes today there are a few efforts under way to use a research-based approach to mitigate this problem.This is an audio version of our Feature Chimpanzees are dying from our colds — these scientists are trying to save themNever miss an episode. Subscribe to the Nature Podcast on Apple Podcasts, Google Podcasts, Spotify or your favourite podcast app. An RSS feed for Nature Podcast is available too. More

Download the Nature Podcast 22 February 2024The deep haunting tones of the world’s largest animals, baleen whales (mysticetes), are iconic. But how the songs are produced has long been a mystery. Whales evolved from land dwelling mammals, which vocalize by passing air through a structure called the larynx — a structure that also helps keep food from entering the respiratory system. However, toothed whales such as dolphins do not use their larynx to make sound, instead they have evolved a specialized organ in their nose. Now a team of researchers have discovered the structure used by baleen whales — a modified version of the larynx. Whales like humpbacks and blue whales are able to create powerful vocalizations but their anatomy also limits the frequency of the sounds they can make and depth at which they can sing. This leaves them unable to escape anthropogenic noise pollution that occurs in the same range.Article: Evolutionary novelties underlie sound production in baleen whalesSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.Never miss an episode. Subscribe to the Nature Podcast on Apple Podcasts, Google Podcasts, Spotify or your favourite podcast app. An RSS feed for the Nature Podcast is available too. More