SCIENCES – CANADA VOICE

BBC culture \ By Isabelle Gerretsen

Could minuscule organisms help the world meet its climate goals?

With global greenhouse gas emissions reaching an all-time high last year, many scientists and world leaders are now arguing that new technologies which can capture carbon and store it underground are needed to help the world meet its climate goals.

And some believe that nature could provide a powerful solution. Microbes – the miniscule organisms that are found all around us but are invisible to the naked eye – play a vital role in capturing carbon and affecting the climate. Plus they could also be harnessed to tackle other environmental problems – such as the drastic fall in pollinator populations.

Scientists have recently discovered a microbe, a type of cyanobacteria, off the coast of a volcanic island near Sicily that eats carbon dioxide (CO2) “astonishingly quickly”.

The island of Vulcano is surrounded by underwater hydrothermal vents, which are rich sources of CO2. These vents are located in shallow water, which means they are exposed to sunlight (unlike vents in the deep ocean). All this has created the perfect environment for the evolution of microbes that use CO2 as a food source.

The microbes found here in September 2022 are “hyper-efficient at consuming CO2 through photosynthesis”, says Braden Tierney, a data scientist focusing on microbiology at Weill Cornell Medical College and Harvard Medical School, and executive director of the Two Frontiers Project, which led the research. The project was funded by US biotechnology company Seed Health, which employs Tierney as a consultant.

Together with a team of researchers from Harvard and Cornell universities in the US and the University of Palermo in Sicily, and with help from the Vulcano community, Tierney isolated a microbe that converted CO2 into biomass faster than other known cyanobacteria. A study outlining the results will be published later this year.

Scientists discovered a type of cyanobacteria that eats CO2 “astonishingly quickly” off the coast of a volcanic island near Sicily (Credit Getty Images)

Cyanobacteria are a type of bacteria that use photosynthesis to obtain energy, capturing carbon in the process, and the new strain is “one of the fastest growing cyanobacteria… ever reported”, says Tierney. He describes cyanobacteria as “nature’s little alchemists” as they absorb large amounts of CO2 and can convert it into useful resources, such as fuels or biodegradable plastics.

“Early data showed [this new strain] generated 22% more biomass than the other fastest growing strains out there,” says Tierney. As it grows denser and heavier, the microbe sinks in the water, which helps it sequester the CO2 it absorbs, he says.

The carbon capture potential of cyanobacteria is already widely studied. What makes this discovery “truly remarkable” is the fact that the cyanobacteria strain can absorb CO2 at such a rapid rate, says Helen Onyeaka, an industrial microbiologist and associate professor at the University of Birmingham in the UK.

“While rapid CO2-consuming microbes have been researched, this particular strain’s absorption rate seems unparalleled,” she says.

A “living database”

This year, Tierney and his team have also travelled to the Rocky Mountains in Colorado in search of more carbon-gobbling microbes. The region is “a hotbed of activity for carbonated springs” and dissolved CO2 concentrations are up to a thousand times higher than Sicily’s volcanic seeps, according to the researchers. Tierney says they isolated microbe strains here with “much higher CO2 levels than what we actually saw in Sicily”.

The team is creating a “living database” which will be available to other scientists worldwide, allowing them to pair DNA sequences with the banked bacteria samples and thus continue studying the microbes long after expeditions.

Cyanobacteria are nature’s little alchemists – Braden Tierney

Tierney says the findings from Vulcano “are expanding our view of billions of years of evolution”. Because of microbes’ ability to adapt to different environmental conditions and planetary changes, he feels “confident that in those evolutionary processes lie the tools we need to address [climate change]”.

CARBON COUNT

The emissions from travel it took to report this story were 0kg CO2. The digital emissions from this story are an estimated 1.2g to 3.6g CO2 per page view. Find out more about how we calculated this figure here.

Scientists say that tackling climate change will require large-scale carbon capture, which could potentially be achieved via new technology or through protecting and enhancing existing natural ecosystems such as forests, peatlands and soils. Last year the UN’s Intergovernmental Panel on Climate Change (IPCC) said that carbon capture is essential because even big cuts to emissions won’t be enough to limit global warming. Although some scientists warn that it could provide governments and industry with an unwarranted excuse to avoid the stringent emissions cuts that are needed to tackle climate change.

Tierney says microbial solutions should be harnessed to “work in concert” with other technologies and natural systems to suck CO2 out of the atmosphere.

Using microbes, such as cyanobacteria and microalgae, for deliberate carbon capture “can be very promising”, says Kira Schipper, a researcher at the Center for Sustainable Development at Qatar University. They grow much faster than conventional crops, which means they capture more carbon in the same time-frame, she adds.

Another benefit is that biomass produced by microbes “can be grown on non-arable land, and in seawater, thereby not competing with food production”, she says. The biomass can be grown in large ponds or bioreactors and used for biofuels, fertilisers, protein supplements and animal feed.

Braden Tierney and his team discovered a microbe that generates 22% more biomass than other fast-growing cyanobacteria strains (Credit: Seed Health / John Kowitz)

Using microbes to capture carbon is more cost-effective than harnessing technologies such as direct air capture, says Onyeaka.

“Microbial processes generally have low operational costs compared to technological interventions for carbon capture, which can often be capital-intensive,” she says. They are also “inherently scalable” as microbes “can be deployed in diverse environments, from open ponds to bioreactors“, she adds.

But technological constraints make scaling up these kinds of systems difficult, says Schipper. “Best-practices to select top strains, to cultivate them at large scale, including maximising the amount of CO2 that is absorbed, and then to harvest the biomass, are challenging and vary drastically between strains and locations.” Some companies have already started implementing systems to capture CO2 using microbes. In the US, LanzaTech uses bacteria to convert CO2 into aviation fuels and chemicals used in products ranging from laundry detergents to perfumes. UK company CyanoCapture is using cyanobacteria to produce biological oils and biomass.

Medicinal microbes

Microbes could also have a multitude of other environmental benefits besides their carbon capture potential. According to a recent Canadian study, for example, they could help revive dying honeybee populations.

Pollinator populations are steadily declining worldwide, and the US saw its highest ever yearly loss rate for honey bee colonies between 2020 and 2021. (Read more: Can we save the bees that feed the world?)

Microbiologist Brendan Daisley from the University of Guelph in Canada set out to combat this “insect apocalypse” by developing probiotics that boost the health of bees.

Just like humans, bees have a microbiome and a healthy balance of microbes in their gut is essential for their overall health. Studies show that pesticides and antibiotics are harming the microbiota of bees, impacting their health.

This is also affecting crop production and food supply, warns Daisley. “It is a cascading effect,” he says. According to a 2020 study, a lack of bees is already limiting the supply of certain crops, including apples, blueberries and cherries, in 13 US states.

By targeting hives with probiotics, the scientists aimed “to re-establish microbial balance in honeybees,” says Daisley, who is a scientific fellow at Seed Health. Alongside a team of researchers from Western University and Lawson Health Research Institute in Canada, he delivered three probiotic strains to more than 30 large commercial hives in California, using a spray and a pollen patty infusion.

Both methods were shown to be highly effective at warding off bacterial and fungal pathogens.

The probiotics also increased the growth of the targeted hives, says Daisley.

Partnering with Seed Health, the scientists are now developing patents for the strains.

Scientists have shown that probiotics can ward off pathogens in honeybee hives (Credit: Getty Images)

Onyeaka warns, however, that while scientific developments such as trialing these honey bee probiotics and the cyanobacteria discovered in Vulcano are promising, it is important to proceed cautiously.

Introducing microbes to the environment in large quantities could disrupt local ecosystems, while carbon storage may not be permanent, she says. “When the microbes die, there’s potential for the carbon to be released back into the environment unless further steps are taken.”

“Before scaling up the use of any microbial solutions, it’s imperative to understand any potential environmental repercussions. We need to ensure the cure isn’t worse than the ailment,” she adds.

Still, scientists are hopeful that microbes can help make our planet healthier and more sustainable.

“Compared to other [carbon capture] solutions, microbes are infinitely replicable,” says Tierney. “While there is no silver bullet for tackling climate change, it is really exciting to find an organism that is a really high performing engine for carbon capture.”

—

Join one million Future fans by liking us on Facebook, or follow us on Twitter or Instagram.

If you liked this story, sign up for the weekly bbc.com features newsletter, called “The Essential List” – a handpicked selection of stories from BBC Future, Culture, Worklife, Travel and Reel delivered to your inbox every Friday.

]]> The mysterious song of the dinosaurs https://canadavoice.info/the-mysterious-song-of-the-dinosaurs/ Thu, 29 Dec 2022 07:52:22 +0000 https://www.canadavoice.info/?p=82713

We tend to associate dinosaurs with ground-shaking roars, but the latest research shows that this is probably mistaken.

BBC cultyre \ By Richard Gray

(Image credit: Alamy)

You’d feel it more than hear it – a deep, visceral throb, emerging from somewhere beyond the thick foliage. Like the rumble of a foghorn, it would thrum in your ribcage and bristle the hairs on your neck. In the dense forests of the Cretaceous period, it would have been terrifying.

We have few clues for what noises dinosaurs might have made while they ruled the Earth before being killed off 66 million years ago. The remarkable stony remains uncovered by palaeontologists offer evidence of the physical prowess of these creatures, but not a great deal about how they interacted and communicated. Sound doesn’t fossilise, of course.

From what we know about animal behaviour, however, dinosaurs were almost certainly not silent.

Now with the help of new, rare fossils and advanced analysis techniques, scientists are starting to piece together some of the clues about how dinosaurs might have sounded.

There is no single answer to this puzzle. Dinosaurs dominated the planet for around 179 million years and during that time, evolved into an enormous array of different shapes and sizes. Some were tiny, like the diminutive Albinykus, which weighed under a kilogram (2.2lbs) and was probably less than 2ft (60cm) long. Others were among the biggest animals to have ever lived on land, such as the titanosaur Patagotitan mayorum, which may have weighed up to 72 tonnes. They ran on two legs, or plodded on four. And along with these diverse body shapes, they would have produced an equally wide variety of noises.

Some dinosaurs had greatly elongated necks – up to 16m (52ft) long in the largest sauropods – which would have likely altered the sounds they produced (think about what happens when a trombone is extended). Others had bizarre skull structures that, much like wind instruments, could have amplified and altered the tone the animals produced. One such creature, a herbivorous hadrosaur named Parasaurolophus tubicen, would have been responsible for the fearsome calls described at the start of this article.

You might also like:

P. tubicen had an enormous crest almost 1m (3.2ft) long protruding from the back of its head. Inside this were three pairs of hollow tubes running from the nose to the top of the crest, where two of the pairs performed a U-bend to wind back down towards the base of the skull and the animal’s airways. The other pair widened to form a large chamber near the top of the crest. In total they formed what was essentially a 2.9m (9.5ft) long resonating chamber.

In 1995, palaeontologists at the New Mexico Museum of Natural History and Science unearthed a nearly complete skull of this unusual looking Parasaurolophus. Using a computerised tomography (CT) scanner, they were able to take 350 images of the crest, allowing them to see inside in unprecedented detail. Then, working with computer scientists, they digitally reconstructed the organ and simulated how it might behave if air was blown through it.

Even without a larynx or voice box, P. tubicen may have still been able to produce sounds using its distinctive headcrest (Credit: Tom Williamson)

“I would describe the sound as otherworldly,” says Tom Williamson, one of those who worked on the dig and is now curator of palaeontology at the museum. “It sent chills through my spine, I remember.”

The closest analogues he can find in living animals today are the vibrating grunts of the southern cassowary, which lives in Australia. This flightless bird emits a series of deep bellows and growls that reverberate through the thick jungle where they live.

“It’s easy for me to imagine a misty Late Cretaceous rainforest setting with those eerie sounds thundering in the background,” says Williamson. “The sounds are of low frequencies – just what is necessary to penetrate the dense undergrowth.”

Fossilised remains of these animals have even inspired some to create musical instruments based on hadrosaur skulls

Williamson and his colleagues simulated the sound P. tubicen might have produced both with and without an assortment of vocal organs, such as the larynx found in mammals and modern reptiles. They found that even without a larynx or the equivalent voice box, the dinosaur may still have produced a noise due to the way air would have resonated inside the crest when the animal blew air through it, much like blowing over the opening of a jug.

“We didn’t have preserved soft tissues and we don’t know, for example, if these dinosaurs had sound-producing organs such as mammals and birds do,” says Williamson. “It became apparent that a sound-producing organ wasn’t necessary to get the crest to resonate because it is such a long structure.”

Other hadrosaurs had similar, if not so dramatic, musical crests on their skulls that are thought to have doubled as a visual display and an aid to vocalisation. Most would have produced low-frequency sounds, and the fossilised remains of these animals have even inspired some to create musical instruments based on hadrosaur skulls.

Tom Williamson says the Parasaurolophus’ sounds would have been “otherworldly” (Credit: Tom Williamson)

Not all dinosaurs were blessed with what amounted to a trumpet atop their heads. And we have no fossilised evidence of voice boxes from dinosaurs, leading some to speculate the animals may even have been mute.

“What we do have are fossil clues that can tell us about different parameters of the airways like its diameter and its length,” says Julia Clarke, a palaeontologist at the University of Texas at Austin. “We can compare those geometries to see how they relate to those dinosaurs that are living today – birds.”

But Clarke has another clue that has provided a further piece of the puzzle. In the mid-2000s, she and her colleagues conducted a detailed examination of the preserved skeleton of an early type of bird found over a decade earlier by Argentinian researchers on Vega Island, a tiny scrap of land on the tip of the Antarctic Peninsula. The fossil itself remains partially embedded in a piece of rock, but using advanced CT scanning techniques, Clarke and her team were able to detect bits of the fossil hidden from view. They then digitally reconstructed the fossil from the scans.

The discovery reveals something else by its presence – that these sound-producing organs can fossilise, and their absence from most dinosaur fossils is telling

And there, nestled amongst the fossilised bone fragments, were the remnants of something astonishing – the mineralised rings of a syrinx, the sound producing organ found in birds, dating back to the time of the dinosaurs.

The primitive bird it belonged to – a goose-like creature called Vegavis iaai – would have coexisted with non-avian dinosaurs at the end of the Cretaceous period, 66-68 million years ago. At around this time, this part of modern Antarctica would have been covered in temperate forests and surrounded by shallow seas. The honking sounds of V. iaai were probably part of that landscape.

But for Clarke, the discovery reveals something else by its presence – that these sound-producing organs can fossilise, and their absence from most dinosaur fossils is telling. Birds, or avian dinosaurs to be more precise, evolved from theropod dinosaurs around 165-150 million years ago during the Jurassic period. If the syrinx from a bird living 66-68 million years ago could be preserved as a fossil, why have none been found among the remains of their extinct non-avian cousins, such as Tyrannosaurus rex?

Would Tyrannosaurus rex have had the fearsome roar portrayed in blockbuster movies? Credit: Roger Harris/SPL/Getty Images)

It is a question that led Clarke to delve deeper into how modern birds produce sound. “There are around 10,000 living species of birds [some estimates put the number as high as 18,000], but there has been surprisingly little scientific research done on what sounds they actually make and how they do it,” she says. Her work has led her to a revelation that will shake the ground from under the feet of five-year-olds and movie goers around the world. Dinosaurs almost certainly didn’t roar. They probably cooed instead.

Or more accurately they may have produced sounds in ways similar to the way doves coo or ostriches boom. Many modern birds use what is known as closed-mouth vocalisation, where sound is made by inflating the throat rather than passing air through the syrinx. Crocodiles – another distant relative of the dinosaurs that split from a common ancestor around 240 million years ago – also use closed-mouth vocalisation to generate deep rumbles that can cause the water around them to “dance” around their bodies. Crocodiles, like other reptiles and mammals, have a larynx rather than a syrinx that produces the sound. But they bypass this when producing their mating bellows.

“The Jurassic Park films have got it wrong,” laughs Clarke. “A lot of the early reconstructions of dinosaurs have been influenced by what we associate with scary noises today from large mammalian predators like lions. In the Jurassic Park movies they did use some crocodilian vocalisations for the large dinosaurs, but on screen the dinosaurs have their mouths open like a lion roaring. They wouldn’t have done that, especially not just before attacking or eating their prey. Predators don’t do that – it would advertise to others nearby that you have got a meal, and it would warn their prey they are there.”

Fossils have also revealed some of the delicate bones that helped dinosaur ears to function

Instead Clarke believes that many non-avian dinosaurs may have produced sounds with their mouths closed by inflating the soft tissues of their throats, as part of some sort of mating display. But she says they could also have used open-mouth calls in other situations, such as moments of distress. “There’s going to be a lot of different kinds of sounds out there in the landscape of the Late Jurassic or Early Cretaceous,” she says.

It is a view supported by research on another part of dinosaur anatomy for which there is better evidence in the fossil record – their ears. Studies of dinosaur skulls have allowed palaeontologists to reconstruct what their inner ears were like. A few fossils have also revealed some of the delicate bones that helped dinosaur ears to function.

“Dinosaurs only had this single bone in their middle ear, the stapes – a key structure in translating vibrations in air, sound waves, to the inner ear that can then be processed by the brain,” says Phil Manning, professor of natural history at the University of Manchester. “Us mammals also possess the malleus (hammer) and the incus (anvil).”

Without these additional pieces of bony hearing apparatus, dinosaurs may only have been able to hear a much narrower range of frequencies compared to mammals, Manning says. And they were probably attuned to picking up low frequency sounds.

Scientists have been able to digitally reconstruct the Parasaurolophus tubes to help figure out what sounds it might have made (Credit: Tom Williamson)

“The stapes in dinosaurs were often quite large, almost the size of a matchstick in T. rex, meaning it was well tuned to lower frequencies,” says Manning. “Small species of dinosaurs with smaller stapes would correlate with high-frequency sounds.”

The size of the cochlear ducts in the inner ears of dinosaur fossils offer other insights about their hearing abilities, and suggest they could have also been able to pick up high frequencies. “We know from living animals that the longer the cochlea, generally the greater range of sounds it can hear,” says Steve Brusatte, professor of palaeontology and evolution at the University of Edinburgh. “Mammal cochleas are coiled like a snake, to pack in a long length into a small region of skull. Dinosaur cochleas aren’t like this, but some of them are pretty long.”

One detailed study of a species of tyrannosaur – a horse-sized predator from the mid-Cretaceous called Timurlengia euotica, which prowled what is now the Kyzylkum Desert in modern-day Uzbekistan – has revealed that these animals had unusually long cochlear ducts in their inner ears. “That suggests that it could hear a wider range of sounds than many other dinosaurs,” says Brusatte who led the study. When we studied the CT scans of Timurlengia, we noticed that its cochlea was really, really long for a dinosaur.”

Could young dinosaurs have been tweeting in their nests to get their parents’ attention, like modern bird chicks?

In fact dinosaurs might have developed these elongated cochleas fairly early on in their evolution, perhaps in the very early days of their branch of the evolutionary tree, known as the Archosauria, around 250 million years ago.

“The cochlear elongation denoting sensitivity to squeaky noises occurred near the origin of the archosaurian ‘ruling reptiles’, which includes birds and crocodiles,” says Bhart-Anjan Bhullar, associate curator of vertebrate paleontology at Peabody Museum of Natural History, Yale University, in New Haven, Connecticu. He has reconstructed the ear canals of several archosaurs using three-dimensional scans of their fossilised skulls. “We considered all sorts of possible drivers of this transformation and realised that the only one that was consistent with all evidence was the advent of a high level of parental care, and more specifically the use of chirping ‘location calls’ by the babies.”

So, could young dinosaurs have been tweeting in their nests to get their parents’ attention, like modern bird chicks and young crocodiles do today? Bhullar thinks they might have. “Given that baby birds and baby crocodiles chirp, it’s reasonable to infer that baby non-bird dinosaurs did as well, and that their parents listened to them and cared for them just as crocodile and bird parents do,” he says. “As far as what sensitivity to high-pitched sound means about the noises that adult non-bird dinosaurs made – it’s an open question. I would be entirely unsurprised if most dinosaurs, and especially those closely related to birds, made a variety of noises.”

Parasaurolophus tubicen is thought to have been capable of some loud and imposing calls (Credit: Tom Williamson)

The ability to hear a wide range of sounds could have been useful in many ways, such as detecting predators or other threats, or allowing them to scout out prey more effectively, says Brusatte. But it could have been used for communication with each other too – either to warn about danger, to attract mates, intimidate rivals or to help herds stick together.

“We know at least some tyrannosaurus travelled and maybe hunted in packs, so communication between individuals was probably important,” says Brusatte.

But with such large animals producing many of these sounds, how would they have sounded to our ears? Much of the booming calls of crocodiles and cassowaries is beyond the limits of human hearing in low frequencies known as infrasound (there are even reports of alligators living close to Cape Canaveral in Florida producing infrasound calls in response to the deep rumble of the rockets during launches of the Space Shuttle in the 1980s). Elephants are also known to communicate over long distances using infrasound and Sumatran rhinos use infrasound “whistles” that resemble humpback whale song to penetrate their thick forest habitat.

Low-frequency sounds and infrasound are especially good at travelling long distances, both in open environments and dense jungle habitats. In animals the size of the T. rex or giant sauropods like the Diplodocus, the sound could have been very low indeed.

Even if we could hear the biggest of the dinosaurs humming to one another, it would have sounded strange to our ears

“We know there is a fundamental scaling relationship between body size and frequency,” says Clarke. “Small animals produce higher frequency sounds in general because of the length of their vocal cords, unless they’ve got some weird modifications. Large animals produce lower frequency sounds. And so in dinosaurs, you have these animals that are the size of four elephants stacked on top of each other. They’re not producing sounds in the frequency range of human hearing.

“But you would probably feel them.”

Other research suggests that even if we could hear the biggest of the dinosaurs humming to one another, it would have sounded strange to our ears. Giants like the Supersaurus may not have had great control over their vocal abilities due to the relatively long delay for nerve signals to travel down the 28m (92ft) long necks from the brain. It would have meant any calls they produced may have seemed remarkably sluggish in relation to events around them.

Some paeolontologists, however, have proposed that giant sauropods like the Diplodocus and Supersaurus might have relied more upon tactile communication while moving in herds. It is perhaps the reason why they have such elongated tails, as they allowed them to stay in almost constant contact with their neighbours while they migrated.

It is evocative to imagine a Cretaceous alive with the squawks of smaller dinosaurs, chirps of newly hatched young and the menacing rumble of giants somewhere in the distance. Faced with such an assault on the ears and vibrating through your bones, it’s worth considering if you would stay to take a closer look, or simply turn and run.

—

Join one million Future fans by liking us on Facebook, or follow us on Twitter or Instagram.

]]>