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Ancient eggshells unlock discovery of extinct elephant bird lineage – Phys.org

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hat a whole Aepyornis egg would have looked like when freshly laid, seen in a market near the town of Toliara on the southwest coast of Madagascar. Credit: Gifford Miller

More than 1,200 years ago, flightless elephant birds roamed the island of Madagascar and laid eggs bigger than footballs. While these ostrich-like giants are now extinct, new research from CU Boulder and Curtin University in Australia reveals that their eggshell remnants hold valuable clues about their time on Earth.

Published today in Nature Communications, the study describes the discovery of a previously unknown, separate lineage of elephant bird that roamed the wet, forested landscapes on the northeastern side of Madagascar—a discovery made without access to any skeletal remains.

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It’s the first time that a new lineage of elephant bird has been identified from ancient eggshells alone, a pioneering achievement which will allow scientists to learn more about the diversity of birds that once roamed the world and why so many have since gone extinct in the past 10,000 years.

“This is the first time a taxonomic identification has been derived from an elephant bird eggshell and it opens up a field that nobody would have thought about before,” said paper co-author Gifford Miller, distinguished professor of geological sciences and faculty fellow at the Institute of Arctic and Alpine Research (INSTAAR) at CU Boulder. “Here may be another way of looking into the past and asking, ‘Was there more diversity in birds than we’re aware of?'”

Akin to a small continent, Madagascar has been separated from Africa and neighboring continents by deep ocean water for at least 60 million years. This geology has allowed evolution to run wild, producing lemurs, elephant birds, and all kinds of animals that exist nowhere else on the planet.

For the Polynesian peoples who arrived here around 2,000 years ago, the largest of the elephant birds, Aepyornis, was a feathery terror to behold: at more than 9 feet tall, weighing more than 1,500 pounds each, and outfitted with a pointy beak and deadly foot talons, it was Madagascar’s largest land animal.

Due to limited —and the fact that bone DNA degrades quickly in warm, humid areas—it was not known until recently where the birds fit into the . The most scientists knew was that they were part of the flightless ratite family, a genetic sister to the New Zealand kiwi, the world’s smallest living ratite.

Ancient eggshell DNA, however, has confirmed not only where the elephant birds sit in this tree, but revealed more about the diversity within the lineage.

“While we found that there were fewer species living in southern Madagascar at the time of their extinction, we also uncovered novel diversity from Madagascar’s far north,” said lead author Alicia Grealy, who conducted this research for her doctoral thesis at Curtin University in Australia. “These findings are an important step forward in understanding the complex history of these enigmatic birds. There’s surprisingly a lot to discover from eggshell.”

<div data-thumb="https://scx1.b-cdn.net/csz/news/tmb/2023/ancient-eggshells-unlo.jpg" data-src="https://scx2.b-cdn.net/gfx/news/hires/2023/ancient-eggshells-unlo.jpg" data-sub-html="Collection and characterization of elephant bird eggshell morphotypes. a Map of Madagascar depicting the geographic location of eggshell samples collected (small circles) and analyzed (larger circles with a border). Samples with genetic data are represented by their ID# and the thickness of the sample is proportional to the icon represented to its right. The location of fossil specimens of aepyornithids (diamonds) and mullerornithids (squares) are shown (Fig.&nbsp;1c; see Supplementary Data&nbsp;1 for locality data and references). Specimens for which DNA data were available are colored yellow, including the four previously published genomes retrieved from bone specimens. Superscripts beside specimens refer to the literature that previously published genetic data for these specimens. Simplified topography of the landscape is shown with rivers represented by fine lines (adapted from https://commons.wikimedia.org/wiki/File:Madagascar_rivers.svg under CC BY-SA 3.0, https://creativecommons.org/licenses/by-sa/3.0/deed.en; river names omitted) and biomes represented by shades of gray (adapted from Brown et al.93 under CC BY 4.0). b The distribution of eggshell thicknesses derived from the total number of eggshells collected across the north and south of Madagascar. Width of eggshell silhouettes are scaled to represent the mean thickness for the morphotype, and are positioned over the X-axis at the mean thickness; the width of the colored bars depict two standard deviations either side of the mean. c Taxonomic revisions for elephant birds with superscripts cross-referencing the original author of the taxonomic name94,95,96,97,98,99,100. Source data for this figure can be found in Supplementary Data&nbsp;1–4. Credit: Nature Communications (2023). DOI: 10.1038/s41467-023-36405-3″>

Ancient eggshells unlock discovery of extinct elephant bird lineage | CU Boulder Today
Collection and characterization of elephant bird eggshell morphotypes. a Map of Madagascar depicting the geographic location of eggshell samples collected (small circles) and analyzed (larger circles with a border). Samples with genetic data are represented by their ID# and the thickness of the sample is proportional to the icon represented to its right. The location of fossil specimens of aepyornithids (diamonds) and mullerornithids (squares) are shown (Fig. 1c; see Supplementary Data 1 for locality data and references). Specimens for which DNA data were available are colored yellow, including the four previously published genomes retrieved from bone specimens. Superscripts beside specimens refer to the literature that previously published genetic data for these specimens. Simplified topography of the landscape is shown with rivers represented by fine lines (adapted from https://commons.wikimedia.org/wiki/File:Madagascar_rivers.svg under CC BY-SA 3.0, https://creativecommons.org/licenses/by-sa/3.0/deed.en; river names omitted) and biomes represented by shades of gray (adapted from Brown et al.93 under CC BY 4.0). b The distribution of eggshell thicknesses derived from the total number of eggshells collected across the north and south of Madagascar. Width of eggshell silhouettes are scaled to represent the mean thickness for the morphotype, and are positioned over the X-axis at the mean thickness; the width of the colored bars depict two standard deviations either side of the mean. c Taxonomic revisions for elephant birds with superscripts cross-referencing the original author of the taxonomic name94,95,96,97,98,99,100. Source data for this figure can be found in Supplementary Data 1–4. Credit: Nature Communications (2023). DOI: 10.1038/s41467-023-36405-3

An eggshell-ent idea

Miller has analyzed eggshell remains in Australia and around the world for more than 20 years—one of few scientists who study these fragments. So, in 2005, when he was awarded $25,000 as part of the Geological Society of America’s Easterbrook Distinguished Scientist Award, Miller gathered a small team to study the evolutionarily elusive elephant bird.

The team initially set out in 2006 to collect elephant bird eggshells from the dry, southern half of the island. When an unaffiliated researcher used to solve this evolutionary mystery before they could, Miller and Grealy’s team turned their attention to the wet, forested north half of the island, hoping to better understand the bird in a different biome.

Using , the team scouted locations where winds had blown the sands away and exposed ancient eggshells. No birds of any similar size currently live on the island, so the cracked pieces are easily recognizable to the naked eye. After the team traversed the island and gathered more than 960 ancient eggshell fragments from 291 locations, the challenging work began: analyzing the ancient DNA.

Due to their chemical makeup, skeletons can be “leaky” with their DNA, making them less ideal for this kind of work. In comparison, the physical chemistry of these thick eggshells locks in its organic matter for up to 10,000 years and protects its DNA like it did the baby bird that once grew inside of it. This means it can be rather difficult to extract for analysis.

Another problem is finding long enough strands of DNA to analyze, as ancient DNA is often degraded. As a result, the scientists pieced together the shorter fragments in a kind of “genetic jigsaw puzzle”—with no idea it would lead them to discover a new type of elephant bird.

“Science often advances in obscure pathways. You don’t always find what you were looking for,” said Miller, director for the Center for Geochemical Analysis of the Global Environment (GAGE) at CU Boulder. “And it’s much more interesting to find what you didn’t know you were looking for.”

The human or the egg?

Miller studies the “Quaternary,” the most recent geological period in Earth’s history and when humans first appeared on the landscape. When humans appeared, he said, often large animals went extinct—but scientists still don’t know why the elephant bird was one of them.

“What is it that early humans are doing that’s resulting in extinction of big animals, especially? This is a debate that’s been going on for my whole life,” said Miller, whose career now spans five decades.

If geologists, archaeologists and biologists are able to gather and date more eggshell fragments from around the world, however, Miller and Grealy’s pioneering work in the field of eggshell DNA science could lead to a better understanding of why large animals like the elephant bird went extinct after the arrival of humans.

“With lots of little contributions from a whole bunch of people, you actually can solve some interesting questions,” said Miller. “This might open up a new way of looking at things.”

More information:
Alicia Grealy et al, Molecular exploration of fossil eggshell uncovers hidden lineage of giant extinct bird, Nature Communications (2023). DOI: 10.1038/s41467-023-36405-3

Citation:
Ancient eggshells unlock discovery of extinct elephant bird lineage (2023, February 28)
retrieved 28 February 2023
from https://phys.org/news/2023-02-ancient-eggshells-discovery-extinct-elephant.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

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The total solar eclipse in North America could shed light on a persistent puzzle about the sun – Phys.org

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The total solar eclipse in North America could shed light on a persistent puzzle about the sun

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The path of eclipse totality passes through Mexico, the US and Canada. Credit: NASA’s Scientific Visualization Studio

A total solar eclipse takes place on April 8 across North America. These events occur when the moon passes between the sun and Earth, completely blocking the sun’s face. This plunges observers into a darkness similar to dawn or dusk.

During the upcoming eclipse, the path of totality, where observers experience the darkest part of the moon’s shadow (the umbra), crosses Mexico, arcing north-east through Texas, the Midwest and briefly entering Canada before ending in Maine.

Total solar eclipses occur roughly every 18 months at some location on Earth. The last that crossed the US took place on August 21 2017.

An international team of scientists, led by Aberystwyth University, will be conducting experiments from near Dallas, at a location in the path of totality. The team consists of Ph.D. students and researchers from Aberystwyth University, Nasa Goddard Space Flight Center in Maryland, and Caltech (California Institute of Technology) in Pasadena.

There is valuable science to be done during eclipses that is comparable to or better than what we can achieve via space-based missions. Our experiments may also shed light on a longstanding puzzle about the outermost part of the sun’s atmosphere—its corona.

The sun’s intense light is blocked by the moon during a total solar eclipse. This means that we can observe the sun’s faint corona with incredible clarity, from distances very close to the sun, out to several solar radii. One radius is the distance equivalent to half the sun’s diameter, about 696,000km (432,000 miles).

Measuring the corona is extremely difficult without an eclipse. It requires a special telescope called a coronagraph that is designed to block out direct light from the sun. This allows fainter light from the corona to be resolved. The clarity of eclipse measurements surpasses even coronagraphs based in space.

We can also observe the corona on a relatively small budget, compared to, for example, spacecraft missions. A persistent puzzle about the corona is the observation that it is much hotter than the photosphere (the visible surface of the sun). As we move away from a hot object, the surrounding temperature should decrease, not increase. How the corona is heated to such high temperatures is one question we will investigate.

We have two main scientific instruments. The first of these is Cip (coronal imaging polarimeter). Cip is also the Welsh word for “glance,” or “quick look.” The instrument takes images of the sun’s corona with a polariser.

The light we want to measure from the corona is highly polarized, which means it is made up of waves that vibrate in a single geometric plane. A polarizer is a filter that lets light with a particular polarization pass through it, while blocking light with other polarizations.

The Cip images will allow us to measure fundamental properties of the corona, such as its density. It will also shed light on phenomena such as the solar wind. This is a stream of sub-atomic particles in the form of plasma—superheated matter—flowing continuously outward from the sun. Cip could help us identify sources in the sun’s atmosphere for certain solar wind streams.

Direct measurements of the magnetic field in the sun’s atmosphere are difficult. But the eclipse data should allow us to study its fine-scale structure and trace the field’s direction. We’ll be able to see how far magnetic structures called large “closed” magnetic loops extend from the sun. This in turn will give us information about large-scale magnetic conditions in the corona.

The second instrument is Chils (coronal high-resolution line spectrometer). It collects high-resolution spectra, where light is separated into its component colors. Here, we are looking for a particular spectral signature of iron emitted from the corona.

It comprises three , where light is emitted or absorbed in a narrow frequency range. These are each generated at a different range of temperatures (in the millions of degrees), so their relative brightness tells us about the coronal temperature in different regions.

Mapping the ‘s temperature informs advanced, computer-based models of its behavior. These models must include mechanisms for how the coronal plasma is heated to such high temperatures. Such mechanisms might include the conversion of magnetic waves to thermal plasma energy, for example. If we show that some regions are hotter than others, this can be replicated in models.

This year’s eclipse also occurs during a time of heightened solar activity, so we could observe a coronal mass ejection (CME). These are huge clouds of magnetized plasma that are ejected from the sun’s atmosphere into space. They can affect infrastructure near Earth, causing problems for vital satellites.

Many aspects of CMEs are poorly understood, including their early evolution near the sun. Spectral information on CMEs will allow us to gain information on their thermodynamics, and their velocity and expansion near the sun.

Our eclipse instruments have recently been proposed for a space mission called moon-enabled solar occultation mission (Mesom). The plan is to orbit the moon to gain more frequent and extended eclipse observations. It is being planned as a UK Space Agency mission involving several countries, but led by University College London, the University of Surrey and Aberystwyth University.

We will also have an advanced commercial 360-degree camera to collect video of the April 8 eclipse and the observing site. The video is valuable for public outreach events, where we highlight the work we do, and helps to generate public interest in our local star, the sun.

Provided by
The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

Citation:
The total solar eclipse in North America could shed light on a persistent puzzle about the sun (2024, March 28)
retrieved 28 March 2024
from https://phys.org/news/2024-03-total-solar-eclipse-north-america.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.


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How the 2024 total solar eclipse is different than the 2017 eclipse



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Mar 30: An Australian Atlantis and other lost landscapes, and more… – CBC.ca

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Quirks and Quarks54:00An Australian Atlantis and other lost landscapes, and more…


On this week’s episode of Quirks & Quarks with Bob McDonald: 

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Archaeologists identify a medieval war-horse graveyard near Buckingham Palace 

Quirks and Quarks9:04Archaeologists identify a medieval war-horse graveyard near Buckingham Palace

We know knights in shining armour rode powerful horses, but remains of those horses are rare. Now, researchers studying equine remains from a site near Buckingham Palace have built a case, based on evidence from their bones, that these animals were likely used in jousting tournaments and battle. Archaeologist Katherine Kanne says the bone analysis also revealed a complex, continent-crossing medieval horse trading network that supplied the British elite with sturdy stallions. This paper was published in Science Advances.

University of Exeter researchers analyzed horse skeletons found near Buckingham Palace and conducted isotope tests on teeth to find out more about the animals’ origins. (University of Exeter)

In an ice-free Arctic, polar bears are dining on duck eggs — and gulls are taking advantage

Quirks and Quarks9:22In an ice-free Arctic, Polar bears are dining on duck eggs — and gulls are taking advantage

Researchers using drones to study ground-nesting birds in the Arctic have observed entire colonies being devastated by marauding polar bears that would normally be out on the ice hunting seals, except the ice isn’t there. What’s more, now they’re enabling a second predator — hungry gulls that raid the nests in the bears’ wake. Andrew Barnas made the observations of this “gull tornado” by following around polar bears in East Bay Island in Nunavut. The research was published in the journal Ecology and Evolution.

Aerial video of a polar bear on grassy, rocky terrain with white birds circling nearby.
A polar bear storms eider duck nests on East Bay island in Nunavut, while herring gulls follow closely behind to snack on any remaining eggs. (Submitted by Andrew Barnas)

A NASA mission might have the tools to detect life on Europa from space

Quirks and Quarks8:05A NASA mission might have the tools to detect life on Europa from space

NASA’s Europa Clipper mission, due to launch this fall, is set to explore the jewel of our solar system: Jupiter’s moon, Europa. The mission’s focus is to determine if the icy moon, thought to harbour an ocean with more water than all of the water on Earth, is amenable to life. However, postdoctoral researcher Fabian Klenner, now at the University of Washington, demonstrated how the spacecraft may be able to detect fragments of bacterial life in a single grain of ice ejected from the surface of the moon. The study was published in the journal Science Advances.

The silhouette of the spacecraft is flying over a brightly pink, blue and orange tinted moon with lots of darker coloured veins underneath with a slightly eclipsed Jupiter looming in the backdrop.
Scientists think under Europa’s icy shell, there is a global, saltwater ocean with twice the volume of Earth’s oceans combined. (NASA/Jet Propulsion Laboratory/Caltech)

Pollution is preventing pollinators from recognizing floral plants by scent

Quirks and Quarks7:50Pollution is preventing pollinators from finding plants by scent

Our polluted air is transforming floral scents so pollinators that spread their pollen can no longer recognize them. In a new study in the journal Science, researchers found that a certain compound in air pollution reacts with the flower’s scent molecules so pollinators — like the hummingbird hawk-moths that pollinate at night — fail to recognize them. Jeremy Chan, a postdoctoral researcher at the University of Naples, said the change in scent made the flowers smell “less fruity and less fresh.”

A huge insect that looks like a hummingbird hovers over a vibrant pink flower with its long antenna inside one of the blooms.
Scientists found that a hummingbird hawk-moth’s ability to recognize the smell of flowers is hampered by air pollution. (Thomas Kienzle/AFP/Getty Images)

An Australian Atlantis and underwater archeological remains in the Baltic 

Quirks and Quarks17:14An Australian Atlantis and underwater archeological remains in the Baltic

During the last ice age, sea levels were more than 100 metres lower than they are today, which means vast tracts of what are currently coastal seafloor were dry land back then. Geologists and archaeologists are searching for these lost landscapes to identify places prehistoric humans might have occupied. These included a country-sized area of Australia that could have been home to half a million people. Archaeologist Kasih Norman and her colleagues published their study of this now-drowned landscape in Quaternary Science Reviews

Another example is an undersea wall off the coast of Northern Germany that preserves an underwater reindeer hunting ground, described in research led by Jacob Geersen, published in the journal PNAS.

a black-and-white depiction of a small group of caribou walking between a low stone wall and an ocean coastline.
An artist’s representation of caribou being directed by a hunters’ stone wall, as it would have appeared 8-11,000 years ago, before rising sea levels left it 20m below the surface of the Baltic Sea. (Michał Grabowski)

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Solar eclipse April 8 – South Grey News

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March 28, 2024

Graphic: Appalachian Mtn Club

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Grey Bruce Public Health is urging residents to resist the temptation to look directly at the sun during the upcoming solar eclipse and take steps to safeguard their visual health during this relatively rare celestial event.

On April 8, 2024, parts of southern and eastern Ontario will experience a total solar eclipse for the first time since 1925. Grey-Bruce will be outside of the so-called Path of Totality — a narrow area where the moon will completely block out the sun — but will still experience a partial eclipse.

The eclipse is expected to begin at about 2 pm and continue until 4:30 pm The eclipse will peak around 3:20 pm.

It is never safe to stare directly at the sun, but it may be tempting to do so during a solar eclipse.

Looking directly at the sun during an eclipse can cause retinal burns, blurred vision, and/or temporary or permanent loss of visual function, according to the Ontario Association of Optometrists. Damage to the eyes can occur without any sensation of pain.

Grey Bruce Public Health advises the following:

  • Do not look directly at the sun without proper eye protection during the solar eclipse. Looking at even a small sliver of the sun before or after the eclipse without proper eye protection can harm vision.
  • Keep a close eye on children and other vulnerable family members during the eclipse to ensure they do not inadvertently look up at the sun without proper eye protection.
  • To safely view the eclipse, ISO-certified eclipse glasses that meet the ISO 12312-2 international safety standard must be worn. Ensure these glasses are in good condition, without any wrinkles or scratches, and that they fully cover the entire field of vision. Put on the glasses when looking away from the sun, then look at the eclipse. Look away from the sun before taking the glasses off.
  • Regular sunglasses or homemade filters will not protect the eyes.
  • It is not safe to view the eclipse through a camera/phone lens, telescope, binoculars, or any other optical device.

Other ways to safely experience the solar eclipse include watching a livestream of the event or creating and using an eclipse box or pinhole projector.

Anyone experiencing temporary vision loss or blurred vision during or after the eclipse should speak with their eye care professional or healthcare provider as soon as possible.

Anyone experiencing blindness (immediate or delayed) after viewing the eclipse must seek emergency care immediately.

More information on the upcoming eclipse is available on the GBPH website.


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South Grey News does not have the resources of a big corporation. We are a small, locally owned-and-operated organization. Research, analysis and physical attendance at public meetings and community events requires considerable effort. But contributions from readers and advertisers, however big or small, go a long way to helping us deliver positive, open and honest journalism for this community.

Please consider supporting South Grey News with a donation in lieu of a subscription fee and let us know that our efforts are appreciated. Thank you.

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