Aclophora linearis

Over half of the world’s crocodilians – a group that includes <a href="https://www.earth.com/news/crocodiles-have-had-great-success-through-rapid-evolution/">crocodiles</a>, alligators, caimans, and gharials – are currently threatened with extinction due to habitat loss, hunting, bycatch in fishing gear, and damming of rivers. A new study led by the <a href="https://www.ox.ac.uk/">University of Oxford</a> in collaboration with the <a href="https://www.zsl.org/">Zoological Society of London</a> (ZSL) has found that losing these endangered species entails losing the diverse ecological roles that they provide, with unknown – and potentially devastating – ecological consequences. According to the experts, about 38 percent of the various ecological functions that crocodilian species provide for wider ecosystems are now at risk of being lost.



The scientists investigated the diversity of crocodilian ecological roles by looking at measurable functions associated to how different species function in their environment, including skull shape, body size, or habitat use. For instance, the prolific burrowing activities of the critically endangered Chinese alligator (Alligator sinensis) provides vital shelter and refuge for other species, while the Philippines crocodile (Crocodylus mindorensis) controls agricultural pests by feeding upon invasive apple snails, and the saltwater crocodile (Crocodylus porosus) – the world’s largest crocodile – travels hundreds of kilometers across open oceans, transporting nutrients between terrestrial, freshwater, and marine habitats.



“If we lose these species, we stand to lose the important roles they play, forever,” said study lead author Phoebe Griffith, a doctoral student in Crocodilian Conservation at Oxford. “We are only just beginning to investigate what these roles are, but some species may be lost before we have chance to understand their place in the ecosystems they are found. This is especially worrying as many of the crocs we highlight as ecologically distinctive are also the species at immediate risk of extinction.”&nbsp;



According to Griffith and her colleagues, certain traits can help to decrease a species’ risk of extinction. For example, species which invest heavily in reproduction, are highly adaptive to different habitats, or can tolerate climate extremes have better chances of survival. However, since crocodilians often occupy fragile habitats, such as freshwaters or coastlines that are under high human pressure, they are at increased risk in many regions of the globe, particularly in and around Asia.



“Our study highlights the highly threatened nature of crocodilians and that immediate, stronger conservation action for many of these species is essential if we are to protect their ecological functions in the freshwater habitats they occur in. This is so important as freshwater habitats are amongst the most threatened on Earth, but provide many critical services for our planet,” Griffith concluded.



The study is published in the journal <a href="https://doi.org/10.1111/1365-2435.14140">Functional Ecology</a>.&nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Loss of crocodilians may have devastating consequences

Over half of the world’s crocodilians – a group that...

A new study led by <a href="https://msu.edu/">Michigan State University</a> (MSU) has found that locusts can reliably detect through smell a variety of human <a href="https://www.earth.com/news/male-dogs-are-more-likely-to-develop-transmissible-cancer/">cancers</a>. The insects can not only “smell” the difference between healthy and cancerous cells, but they can also distinguish between different cancer cell lines. These findings could provide a basis for devices which use locust sensory neurons to enable the early detection of cancer by using only biomarkers in a patient’s breath.



“Noses are still state of the art,” said study senior author&nbsp;Debajit Saha, an assistant professor of Biomedical Engineering at MSU. “There’s really nothing like them when it comes to gas sensing. People have been working on ‘electronic noses’ for more than 15 years, but they’re still not close to achieving what biology can do seamlessly.”



Cancer cells function differently from healthy ones, and create different chemical compounds as they grow. If these chemicals reach the lungs or airways – which happens in most types of cancer – they can be detected in exhaled breath. “Theoretically, you could breathe into a device, and it would be able to detect and differentiate multiple cancer types and even which stage the disease is in. However, such a device isn’t yet close to being used in a clinical setting,” Professor Saha explained.



By attaching electrodes to their brain and recording their responses to gas samples produced by both healthy and cancer cells, the researchers investigated how well locusts – model organisms widely used in the scientific community - could differentiate these different types of cells in the case of three distinct oral cancer cell lines. “We expected that the cancer cells would appear different than the normal cells,” said study co-author Christopher Contag, a professor of Biomedical Engineering at MSU. “But when the bugs could distinguish three different cancers from each other, that was amazing.” 



Although the team focused only on mouth cancers, they believe this system could work with any cancer that introduces metabolites into breath, which is likely most cancer types. By using the information recorded from locusts’ neural systems, they aim to develop portable sensors that could analyze volatile cancer biomarkers before other, more invasive techniques can reveal the disease.



“Early detection is so important, and we should use every possible tool to get there, whether it’s engineered or provided to us by millions of years of natural selection. If we’re successful, cancer will be a treatable disease,” Professor Contag concluded.



A preprint of the study can be found on <a href="https://www.biorxiv.org/content/10.1101/2022.05.24.493311v1">bioRxiv</a>. &nbsp;&nbsp;&nbsp;  &nbsp; &nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Locusts can detect cancer in humans

A new study led by Michigan State University (MSU) has...

Rising temperatures pose major challenges to the dairy industry. For instance, the milk production of Holstein cattle can decline by 30 to 70 percent in hot weather. According to a research team from <a href="https://www.cornell.edu/">Cornell University</a>, heat-stressed <a href="https://www.earth.com/news/dairy-cows-exposed-to-wildfire-smoke-produce-less-milk/">dairy cows</a> often develop gut permeability (leaky gut), which contributes to a significant reduction in milk production. However, the experts found that milk production can be partially restored by feeding the cows organic acids and pure botanicals.&nbsp;



“This has immediate application,” said&nbsp;study senior author Joseph McFadden, an associate professor of Dairy Cattle Biology at Cornell. “And we hope it serves as a catalyst for the field and ignites further research into dietary approaches.”



Climate change is already causing reduced milk production in Holsteins, the dominant dairy cattle breed in the United States. Even in the New York state, where the climate is generally cooler, these cows’ health and productivity are threatened, since they start experiencing heat stress at about 75 degrees Fahrenheit.



“In New York state,&nbsp;we’re projected to have an increase in heat-stress events in the next decade, but the precipitation is supposed to stay. With major droughts and water demands in other areas of the country, there may be an increased emphasis on maintaining the strength of the Northeast dairy industry, but we’ll still have more heat-stress events, and we have to be proactive and ready,” Professor McFadden urged.



Heat stress is causing the cows to eat less, and this reduced food intake accounts for 30 to 50 percent of the drop in milk production. According to McFadden and his team, the remaining decline develops due to an increase in intestinal permeability, which activates the immune system. “The general working hypothesis was that an activated immune system partitions energy away from milk production to support immune function,” he explained.&nbsp;



“When the gut becomes permeable, it allows bacteria to enter the cow that activate the immune system and cause inflammation. But there had never been a study that directly confirmed that heat-stressed dairy cows developed leaky gut. Prior data only inferred this possibility.”



Fortunately, the scientists discovered that the consumption of organic acids and pure botanicals significantly reduces cows’ gut permeability and increases food intake and milk production, restoring up to three kilograms of milk per day. Moreover, cows kept on this diet showed increased nitrogen efficiency, thus reducing emissions of this harmful substance.



Further research is needed to assess the efficacy of different additives, and recommend changes to the staple diet of cows in the U.S. through optimization of the&nbsp;<a href="https://cals.cornell.edu/animal-science/outreach-extension/publications-resources-software/cornell-net-carbohydrate-and-protein-system#:~:text=The%20Cornell%20Net%20Carbohydrate%20and,supplying%20nutrients%20to%20meet%20requirements.">Cornell Net Carbohydrate and Protein System</a> (a model used to determine what dairy and beef cattle should eat). “That model helps nutritionists formulate diets for cows. If we can improve that model and understand the nutrient requirements that a cow has during a heat-stress event, we can ensure she’s getting what she needs to maintain optimum health and performance,” McFadden concluded.



The study is published in the <a href="http://dx.doi.org/10.3168/jds.2022-21820">Journal of Dairy Science</a>. &nbsp;&nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Dietary changes improve milk production in heat-stressed cows

Rising temperatures pose major challenges to the dairy industry. For...

Earth,And,Galaxy.,Elements,Of,This,Image,Furnished,By,Nasa.

Major <a href="https://www.earth.com/news/habitat-shifts-change-the-brain-structure-of-butterflies/">habitat shifts</a>, such as moving to land from the sea, are key evolutionary events that often spark explosions of diversity. Until recently, it was unclear how frequent such habitat transitions have been across the eukaryotic tree of life, which includes animals, plants, and a vast array of microbes. Now, an international research team led by the <a href="https://www.uu.se/">Uppsala University</a> in Sweden has discovered that eukaryotes have made hundreds of major leaps from sea to land and freshwater habitats, and vice versa, during their evolution over the last two billion years.



“We found that organisms in the eukaryote tree of life are generally grouped by whether they live in the oceans, or in non-marine habitats like freshwater and soils. This finding confirms that adapting to a different salinity - or crossing the salt barrier - is difficult, even for microbes,” said study lead author Mahwash Jamy, an expert in Organismal Biology at Uppsala.



“However, we found that microbial eukaryotes have still managed to successfully establish themselves in new habitats several hundred times during their evolution, and we’re likely to discover more of these transition events as we sequence microbes from more locations. It’s likely that these difficult-to-achieve transitions have allowed colonizing organisms to occupy vacant ecological niches, leading to the vast diversity of eukaryotes we see today.”



By sequencing DNA of microbes from boreal lakes, forest soils, the Indian Ocean, the Mariana Trench, and various other environments, the scientists reconstructed large evolutionary trees that revealed major patterns in the evolution of habitat preference. &nbsp;“It’s likely that two of the largest groups of eukaryotes, called SAR and Obozoa, each of which are much larger than the plant and animal kingdoms, arose in completely different habitats,” explained study senior author Fabien Burki, an associate professor of Organismal Biology at Uppsala.&nbsp;



“The SAR lineage, which includes groups like diatoms, ciliates, dinoflagellates, radiolarians etc., first arose in the Precambrian oceans. On the other hand, the ancestral Obazoan, which has now diversified into fungi, animals, choanoflagellates, and amoebozoans, likely inhabited non-marine habitats.”



These findings suggest that the salinity shift between marine and non-marine habitats played a crucial role in shaping eukaryotic evolution. Further research is needed to investigate what genetic mechanisms are underlying these seminal evolutionary events.



The study is published in the journal <a href="https://www.nature.com/articles/s41559-022-01838-4">Nature Ecology &amp; Evolution</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Habitat shifts shaped the evolution of life on Earth

Major habitat shifts, such as moving to land from the...

In a new study, researchers at <a href="https://duke.edu/">Duke University</a> have found that hybrid baboons got about one-third of their <a href="https://www.earth.com/news/insects-have-inherited-hundreds-of-genes-from-microbes/">genes</a> from another, closely-related species. The experts found evidence that some of these borrowed genes came at a cost for the interbred animals.&nbsp;



The genetic study was focused on wild baboons in southern Kenya near Amboseli National Park, where yellow baboons often encounter and intermix with Anubis baboons from the northwest. These individuals have been monitored since 1971 as part of the Amboseli Baboon Research Project. Scientists with the project have documented when the animals mated with outsiders and have observed the offspring throughout their lives.&nbsp;



According to five decades of observations, there have been no obvious signs that hybrids fare any worse than their counterparts. In fact, baboons with more anubis DNA in their genome were found to mature faster, form stronger social bonds, and have more mating success.&nbsp;



The Duke study, however, indicates that there are potential consequences of intermixing that are not so obvious. Professor Jenny Tung, who led the study with her doctoral students Tauras Vilgalys and Arielle Fogel, said the research sheds light on how the diversity of species on Earth is maintained even when the genetic lines between species are blurry.



According to Fogel, interspecies mating is surprisingly common in animals - 20 to 30 percent of apes, monkeys and other primate species interbreed and mix their genes with others.



The researchers set out to investigate the possible costs and benefits of genetic mixing in primates, including humans. They analyzed the genomes of 440 Amboseli baboons across nine generations.



The study revealed that all of the baboons in the Amboseli are a mix, with anubis DNA making up an average of 37 percent of their genomes. Some of the interbreeding was recent - within the last seven generations. For about half of the baboons, however, the mixing happened hundreds to thousands of generations ago.



During that time, the data show that certain bits of anubis DNA came at a cost for the hybrids who inherited them, affecting their survival and reproduction in such a way that these genes are less likely to show up in their descendants’ genomes today, explained Vilgalys.



The researchers said that the baboons at Amboseli offer clues to the costs of the hybridization. Vilgalys noted that genomic data allows researchers to look back many more generations and study historical processes that can’t be seen directly in the field.



“But you need to look at the animals themselves to understand what genetic changes actually mean,” said Professor Tung. “You need both fieldwork and genetics to get the whole story.”



“We’re not saying this is what Neanderthal and Denisovans genes did in humans. But the baboon case makes it clear that genomic evidence for costs to hybridization can be consistent with animals that not only survive, but often thrive.”



The study is published in the journal <a href="https://www.science.org/">Science</a>.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Hybridization among wild baboons comes with hidden costs

In a new study, researchers at Duke University have found...

Birds are described as modern-day dinosaurs, and it seems they will be forced, yet again, to adapt to a rapidly changing world. A team of scientists led by <a href="https://www.durham.ac.uk/homepage/">Durham University</a> has predicted that climate change will force avian communities worldwide to shift their ranges by 2080.



To make their predictions for the future, the researchers looked at the past. They compared previous climate data to past avian ranges to determine where the birds might move. The experts then applied these relationships to a model that considered future climates based on low and high greenhouse emissions.&nbsp;



The team was interested in more than the number of birds and species diversity. They wanted to determine the effect the shift will have on phylogenetic diversity, which factors in how many different types of birds make up a community.&nbsp;



“In our study, we examined the effects of global warming on the regional distribution of terrestrial birds around the world," said Dr. Alke Voskamp of Senckenberg Biodiversity and Climate Research Centre. "The focus was on the effects on species richness as well as on various aspects of phylogenetic diversity, primarily how closely related the species are to each other.”



The researchers analyzed 8,768 bird species to help them determine how many lineages might be lost or added regionally as birds move and adapt to a dynamic climate. They believe most losses will occur in tropical and subtropical areas but that community restructuring will take place worldwide.&nbsp;



The study points out that maintaining regional phylogenetic diversity will be crucial to the resilience of over biological diversity.



“The diversity of lineages is very often related to the diversity of traits that species possess and thus to their roles and functions in ecosystems," said study co-author Professor Stephen Willis of Durham University.



"For example, species from more distant lineages often have different beak types, and hence eat different types of food. Change means that the ecosystem functions that birds perform in an area may also change in the future, with potential consequences for food webs, seed dispersal and plant pollination.”



Readers can access the study in <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2021.2184">Proceedings of the Royal Society B</a>.



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By <a href="mailto:nire518@gmail.com">Erin Moody </a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Climate change will severely impact birds by 2080

Birds are described as modern-day dinosaurs, and it seems they...

Until recently, scientists thought that <a href="https://www.earth.com/news/climate-change-may-cause-stingrays-to-move-toward-danger/">stingrays</a>, as well as other elasmobranchs such as sharks and skates, are mostly silent. However, a new study published in the journal <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.3812">Ecology</a> has provided evidence that two species of stingray – the mangrove whipray (Urogymnus granulatus) and the cowtail stingray (Pastinachus ater) – can produce striking, unmistakable clicks.



Before the current study, the only evidence that stingrays could make sounds came from a <a href="https://www.worldcat.org/title/sounds-of-western-north-atlantic-fishes-a-reference-file-of-biological-underwater-sounds/oclc/92568">study</a> of captive cownose rays from 1970, which recorded a series of short, sharp clicks produced by these animals after the scientists forcefully prodded them. However, while diving in Indonesia and Australia in 2017 and 2018, the new study’s authors have managed to witness and record sounds produced by stingrays in their natural habitat.&nbsp;



The precise mechanism through which the animals make these sounds remains a mystery though. “They don’t have vocal cords, and there’s no clear mechanism for how they do it,” said study lead author Lachlan Fetterplace, a marine ecologist at the <a href="https://www.slu.se/en/">Swedish University of Agricultural Sciences</a>. As the clicking sounds are heard, the rays’ spiracles – the two holes in their heads used to move water across their gills – seem to contract, suggesting that the animals might be creating friction between the spiracles and the surrounding tissue, in a process similar to when we snap our fingers. However, according to Dr. Fetterplace, it is also possible that the stingrays are forming the sounds by creating a vacuum, such as when we click our tongues.



The scientists are also uncertain about the function of these sounds. By comparing the bandwidth and frequencies of the clicks to the known range of stingray hearing, they confirmed that stingrays can hear them, which could mean they are a form of communication. However, since also reef sharks and sicklefin lemon sharks – which feed upon rays – can hear the sounds, they may be produced as warnings at the approach of these predators, or as a diversion aiming to surprise the predators and allow the rays to escape. Finally, the fact that other stingrays were observed to quickly approach the one making the sounds suggests that the clicks could be a way to call reinforcements.&nbsp;



Further research is needed to clarify the ways in which these sounds are produced, their frequency among stingray populations, and the range of functions they might have, as well as to discover whether other related species are making similar sounds.



“Other similar species may also produce sounds but anecdotal records may have not yet come to light; thus our paper may serve to bring to light further examples from the public and researchers,” the scientists concluded.&nbsp;



A video of the sounds produced by stingrays can be viewed <a href="https://youtu.be/Cj1R1Ilbckk">here</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Stingray sounds recorded for the first time

Until recently, scientists thought that stingrays, as well as other...

Aclophora linearis

Taxonomic tree: