Scientists discover a nitroplast, the 1st of its kind

@earthsky.org This has only happened 4 times in Earth's history! #Earth #science #cells #mitochondria #bacteria #news #discovery ? Space – lofi'chield

Watch Will Triggs of EarthSky in this viral video on the discovery of the first ever nitroplast.

UCSC published this original story on April 11, 2024. Edits by EarthSky.

Discovery of the 1st nitroplast

Modern biology textbooks assert that only bacteria can take nitrogen from the atmosphere and convert it into a form that is usable for life. Plants that fix nitrogen, such as legumes, do so by harboring symbiotic bacteria in root nodules. But a recent discovery upends that rule.

In two recent papers, an international team of scientists describe the first known nitrogen-fixing organelle within a eukaryotic cell. The organelle is the 4th example in history of primary endosymbiosis. This is the process by which a prokaryotic cell is engulfed by a eukaryotic cell and evolves beyond symbiosis into an organelle.

Tyler Coale, a postdoctoral scholar at UC Santa Cruz and first author on one of two recent papers, said:

It’s very rare that organelles arise from these types of things. The first time we think it happened, it gave rise to all complex life. Everything more complicated than a bacterial cell owes its existence to that event [the origin of the mitochondria]. A billion years ago or so, it happened again with the chloroplast, and that gave us plants.

The 3rd known instance involves a microbe similar to a chloroplast. The newest discovery is the first example of a nitrogen-fixing organelle, which the researchers are calling a nitroplast.

A microscope image shows the marine haptophyte algae Braarudosphaera bigelowii with a black arrow pointing to the nitroplast organelle. Image via Tyler Coale/ UCSC.

A decades-long mystery

The discovery of the organelle involved a bit of luck and decades of work. In 1998, Jonathan Zehr, a UC Santa Cruz distinguished professor of marine sciences, found a short DNA sequence of what appeared to be from an unknown nitrogen-fixing cyanobacterium in Pacific Ocean seawater. Zehr and colleagues spent years studying the mystery organism, which they called UCYN-A.

At the same time, Kyoko Hagino, a paleontologist at Kochi University in Japan, was painstakingly trying to culture a marine alga. It turned out to be the host organism for UCYN-A. It took her over 300 sampling expeditions and more than a decade, but Hagino eventually successfully grew the alga in culture, allowing other researchers to begin studying UCYN-A and its marine alga host together in the lab.

For years, the scientists considered UCYN-A an endosymbiont that was closely associated with an alga. But the two recent papers suggest that UCYN-A has co-evolved with its host past symbiosis and now fits criteria for an organelle.

Organelle origins

In a paper published in Cell in March, Zehr and colleagues from the Massachusetts Institute of Technology, Institut de Ciències del Mar in Barcelona and the University of Rhode Island show the size ratio between UCYN-A and their algal hosts is similar across different species of the marine haptophyte algae Braarudosphaera bigelowii.

The researchers use a model to demonstrate that the growth of the host cell and UCYN-A are controlled by the exchange of nutrients. Their metabolisms are linked. This synchronization in growth rates led the researchers to call UCYN-A “organelle-like.” Zehr said:

That’s exactly what happens with organelles. If you look at the mitochondria and the chloroplast, it’s the same thing: they scale with the cell.

Evidence for the nitroplast

But the scientists did not confidently call UCYN-A an organelle until confirming other lines of evidence. In the cover article of the journal Science, published on April 11, 2024, Zehr, Coale, Kendra Turk-Kubo and Wing Kwan Esther Mak from UC Santa Cruz, and collaborators from the University of California, San Francisco, the Lawrence Berkeley National Laboratory, National Taiwan Ocean University, and Kochi University in Japan show that UCYN-A imports proteins from its host cells.

Zehr said:

That’s one of the hallmarks of something moving from an endosymbiont to an organelle. They start throwing away pieces of DNA, and their genomes get smaller and smaller, and they start depending on the mother cell for those gene products – or the protein itself – to be transported into the cell.

Tyler Coale worked on the identification and characterization for the study. He compared the proteins found within isolated UCYN-A with those found in the entire algal host cell. He found the host cell makes proteins and labels them with a specific amino acid sequence, which tells the cell to send them to the nitroplast. The nitroplast then imports the proteins and uses them. Coale identified the function of some of the proteins, and they fill gaps in certain pathways within UCYN-A.

Zehr said:

It’s kind of like this magical jigsaw puzzle that actually fits together and works.

In the same paper, researchers from UCSF show that UCYN-A replicates in synchrony with the alga cell and is inherited like other organelles.

Changing perspectives

These independent lines of evidence leave little doubt that UCYN-A has surpassed the role of a symbiont. And while mitochondria and chloroplasts evolved billions of years ago, the nitroplast appears to have evolved about 100 million years ago, providing scientists with a new, more recent perspective on organellogenesis [the origin of organelles].

The organelle also provides insight into ocean ecosystems. All organisms need nitrogen in a biologically usable form, and UCYN-A is globally important for its ability to fix nitrogen from the atmosphere. Researchers have found it everywhere from the tropics to the Arctic Ocean, and it fixes a significant amount of nitrogen. Zehr said:

It’s not just another player.

Agricultural uses of the nitroplast

The discovery also has the potential to change agriculture. The ability to synthesize ammonia fertilizers from atmospheric nitrogen allowed agriculture – and the world population – to take off in the early 20th century. Known as the Haber-Bosch process, it makes possible about 50% of the world’s food production. It also creates enormous amounts of carbon dioxide. About 1.4% of global emissions come from the process. For decades, researchers have tried to figure out a way to incorporate natural nitrogen fixation into agriculture. Coale said:

This system is a new perspective on nitrogen fixation, and it might provide clues into how such an organelle could be engineered into crop plants.

But plenty of questions about UCYN-A and its algal host remain unanswered. The researchers plan to delve deeper into how UCYN-A and the alga operate and study different strains.

Kendra Turk-Kubo, an assistant professor at UC Santa Cruz, will continue the research in her new lab. Zehr expects scientists will find other organisms with evolutionary stories similar to UCYN-A, but as the first of its kind, this discovery is one for the textbooks.

Bottom line: Scientists announced the discovery of the first nitroplast, a nitrogen-fixing organelle. It’s just the 4th example in history of primary endosymbiosis.

Via UCSC

Read more: Algae discovered inside salamander embryos

The post Scientists discover a nitroplast, the 1st of its kind first appeared on EarthSky.

from EarthSky https://ift.tt/fw1eoum

@earthsky.org This has only happened 4 times in Earth's history! #Earth #science #cells #mitochondria #bacteria #news #discovery ? Space – lofi'chield

Watch Will Triggs of EarthSky in this viral video on the discovery of the first ever nitroplast.

UCSC published this original story on April 11, 2024. Edits by EarthSky.

Discovery of the 1st nitroplast

Modern biology textbooks assert that only bacteria can take nitrogen from the atmosphere and convert it into a form that is usable for life. Plants that fix nitrogen, such as legumes, do so by harboring symbiotic bacteria in root nodules. But a recent discovery upends that rule.

In two recent papers, an international team of scientists describe the first known nitrogen-fixing organelle within a eukaryotic cell. The organelle is the 4th example in history of primary endosymbiosis. This is the process by which a prokaryotic cell is engulfed by a eukaryotic cell and evolves beyond symbiosis into an organelle.

Tyler Coale, a postdoctoral scholar at UC Santa Cruz and first author on one of two recent papers, said:

It’s very rare that organelles arise from these types of things. The first time we think it happened, it gave rise to all complex life. Everything more complicated than a bacterial cell owes its existence to that event [the origin of the mitochondria]. A billion years ago or so, it happened again with the chloroplast, and that gave us plants.

The 3rd known instance involves a microbe similar to a chloroplast. The newest discovery is the first example of a nitrogen-fixing organelle, which the researchers are calling a nitroplast.

A microscope image shows the marine haptophyte algae Braarudosphaera bigelowii with a black arrow pointing to the nitroplast organelle. Image via Tyler Coale/ UCSC.

A decades-long mystery

The discovery of the organelle involved a bit of luck and decades of work. In 1998, Jonathan Zehr, a UC Santa Cruz distinguished professor of marine sciences, found a short DNA sequence of what appeared to be from an unknown nitrogen-fixing cyanobacterium in Pacific Ocean seawater. Zehr and colleagues spent years studying the mystery organism, which they called UCYN-A.

At the same time, Kyoko Hagino, a paleontologist at Kochi University in Japan, was painstakingly trying to culture a marine alga. It turned out to be the host organism for UCYN-A. It took her over 300 sampling expeditions and more than a decade, but Hagino eventually successfully grew the alga in culture, allowing other researchers to begin studying UCYN-A and its marine alga host together in the lab.

For years, the scientists considered UCYN-A an endosymbiont that was closely associated with an alga. But the two recent papers suggest that UCYN-A has co-evolved with its host past symbiosis and now fits criteria for an organelle.

Organelle origins

In a paper published in Cell in March, Zehr and colleagues from the Massachusetts Institute of Technology, Institut de Ciències del Mar in Barcelona and the University of Rhode Island show the size ratio between UCYN-A and their algal hosts is similar across different species of the marine haptophyte algae Braarudosphaera bigelowii.

The researchers use a model to demonstrate that the growth of the host cell and UCYN-A are controlled by the exchange of nutrients. Their metabolisms are linked. This synchronization in growth rates led the researchers to call UCYN-A “organelle-like.” Zehr said:

That’s exactly what happens with organelles. If you look at the mitochondria and the chloroplast, it’s the same thing: they scale with the cell.

Evidence for the nitroplast

But the scientists did not confidently call UCYN-A an organelle until confirming other lines of evidence. In the cover article of the journal Science, published on April 11, 2024, Zehr, Coale, Kendra Turk-Kubo and Wing Kwan Esther Mak from UC Santa Cruz, and collaborators from the University of California, San Francisco, the Lawrence Berkeley National Laboratory, National Taiwan Ocean University, and Kochi University in Japan show that UCYN-A imports proteins from its host cells.

Zehr said:

That’s one of the hallmarks of something moving from an endosymbiont to an organelle. They start throwing away pieces of DNA, and their genomes get smaller and smaller, and they start depending on the mother cell for those gene products – or the protein itself – to be transported into the cell.

Tyler Coale worked on the identification and characterization for the study. He compared the proteins found within isolated UCYN-A with those found in the entire algal host cell. He found the host cell makes proteins and labels them with a specific amino acid sequence, which tells the cell to send them to the nitroplast. The nitroplast then imports the proteins and uses them. Coale identified the function of some of the proteins, and they fill gaps in certain pathways within UCYN-A.

Zehr said:

It’s kind of like this magical jigsaw puzzle that actually fits together and works.

In the same paper, researchers from UCSF show that UCYN-A replicates in synchrony with the alga cell and is inherited like other organelles.

Changing perspectives

These independent lines of evidence leave little doubt that UCYN-A has surpassed the role of a symbiont. And while mitochondria and chloroplasts evolved billions of years ago, the nitroplast appears to have evolved about 100 million years ago, providing scientists with a new, more recent perspective on organellogenesis [the origin of organelles].

The organelle also provides insight into ocean ecosystems. All organisms need nitrogen in a biologically usable form, and UCYN-A is globally important for its ability to fix nitrogen from the atmosphere. Researchers have found it everywhere from the tropics to the Arctic Ocean, and it fixes a significant amount of nitrogen. Zehr said:

It’s not just another player.

Agricultural uses of the nitroplast

The discovery also has the potential to change agriculture. The ability to synthesize ammonia fertilizers from atmospheric nitrogen allowed agriculture – and the world population – to take off in the early 20th century. Known as the Haber-Bosch process, it makes possible about 50% of the world’s food production. It also creates enormous amounts of carbon dioxide. About 1.4% of global emissions come from the process. For decades, researchers have tried to figure out a way to incorporate natural nitrogen fixation into agriculture. Coale said:

This system is a new perspective on nitrogen fixation, and it might provide clues into how such an organelle could be engineered into crop plants.

But plenty of questions about UCYN-A and its algal host remain unanswered. The researchers plan to delve deeper into how UCYN-A and the alga operate and study different strains.

Kendra Turk-Kubo, an assistant professor at UC Santa Cruz, will continue the research in her new lab. Zehr expects scientists will find other organisms with evolutionary stories similar to UCYN-A, but as the first of its kind, this discovery is one for the textbooks.

Bottom line: Scientists announced the discovery of the first nitroplast, a nitrogen-fixing organelle. It’s just the 4th example in history of primary endosymbiosis.

Via UCSC

Read more: Algae discovered inside salamander embryos

The post Scientists discover a nitroplast, the 1st of its kind first appeared on EarthSky.

from EarthSky https://ift.tt/fw1eoum

Colorful iguanas are our lifeform of the week

Watch a video about iguanas, our lifeform of the week!

Iguanas are reptiles that resemble miniature dinosaurs. Did you know they can change colors or detach their tails? Or that iguanas have a third eye? Read on to discover more cool facts about these curious animals.

Meet the iguanas

Iguanas are reptiles that measure between 20 inches (50 cm) and 80 inches (2 m) long from head to tail. Their hind legs are considerably larger than their front legs. But on all four legs, they have quite strong claws that allow them to climb trees without falling. Plus, they can survive falls up to 50 feet (15 m) high. This ability is important because they live among tree branches.

In fact, despite their formidable appearance and sharp teeth, iguanas are herbivorous, or plant eaters. They feed mainly on leaves, flowers and fruits. Much of their water intake comes from the plants and flowers they eat. And no, they don’t eat insects. These reptiles usually live between 10 to 20 years.

These cold-blooded animals need heat and sun to survive. That’s why they usually live in temperate or hot climates and love to sunbathe. Furthermore, sunbathing is not a whim but a necessity. Among other things, sunlight gives iguanas the vitamin D they need to absorb enough calcium.

Iguanas live among tree branches and eat leaves, flowers and fruits. Image via Joanna Borkowska/ Unsplash.

Anatomy

The extra skin under an iguana’s head is called the dewlap. It helps regulate an iguana’s temperature. And the spikes on the back and tail function as a solar collector that provides a greater surface area for absorbing heat and ultraviolet rays. Thus, iguanas stay warm longer and more effectively.

These reptiles have incredible eyesight that allow them to see colors, shadows and shapes from a long distance. In turn, that helps them anticipate predators, since their hearing is not the best. And they have well-developed lungs and breathe air just like humans.

Iguanas have a longer middle digit on their hind legs, which they use to climb trees. And they can use the tail for defense, to swim or as a stabilizer when jumping or climbing trees. In fact, iguanas are excellent swimmers. It’s hard to believe, but there are marine iguanas capable of diving for almost half an hour. These iguanas have the ability to forage in the sea for algae, which makes up almost all their diet.

Iguanas have spikes on their backs and tails to provide a greater surface area for absorbing heat and ultraviolet rays. Image via Orlando Madrigal/ Unsplash.

Colors

Iguanas have skin covered in small scales with the ability to change color. They use this ability to blend in with their environment and to hide from their predators. For example, the females can then go unnoticed when pregnant. But they can also change color to attract attention during heat. If an iguana is stressed or sick, it will change its color to dark shades.

You can find iguanas with a multitude of colors such as green, orange, yellow, purple, blue, white, black and red. And there are iguanas that have a combination of colors.

A blue iguana. Image via Anthony/ Unsplash.

A black and white iguana. Image via Andrés Oropeza/ Unsplash.

Some iguanas have a combination of different colors. Image via Alex Williams/ Unsplash.

Skin and tail

Between the hard scales iguanas have quite flexible skin. Therefore, they have both protection and agility. Additionally, iguanas shed their skin.

Iguanas can detach their own tail. This is a defense mechanism called caudal autotomy that many lizards have. When a predator chases or catches them, these animals have the ability to get rid of their tail. Would you believe the tail remains moving for a few minutes on the ground or in the predator’s mouth? This distraction allows the lizard to escape.

Their tails come off, but they can also regenerate them. The new tail grows at a rate of approximately 0.2 inches (0.5 cm) per day. But it won’t be the same as the original tail. The texture is rougher and also has a more opaque color than the original. The new tail is shorter and the scales are smaller and irregularly placed. In fact, the ridge of spines on iguanas won’t regenerate. And if there is any color pattern or drawing, it is generally altered.

Iguanas have various fat reserves in their body, and one of them is the tail, which functions as both an energy reserve and to produce some hormones that function for their reproduction. So, although they can detach their tail, it’s best that this doesn’t happen, since infections can also occur until the wound heals.

Iguanas can detach and then regenerate their tails. Image via Michael Payne/ Unsplash.

The third eye

Just like in Lord of the Rings, iguanas also have an all-seeing eye. Just kidding, it doesn’t see it all! But it is true that in addition to their two regular eyes, iguanas have a third eye located on the top of their head. It’s known as parietal eye. And iguanas use them to more accurately detect prey and predators approaching from above. Many amphibians also possess this third eye.

This organ is a modified scale that functions as a light receptor to detect some predators. It can even help the animal know what time of year it is and regulate some physiological processes such as reproduction.

Iguanas have a 3rd eye. Image via Nick Karvounis/ Unsplash.

Behavior of iguanas

Iguanas are solitary animals; they only get together in groups during mating seasons. During this time, a group of females gathers around a single male.

Something very curious about iguanas is their courtship method. In this process, male iguanas move their head (and dewlap) up and down as if to say “Yes, I mean you,” while moving their tail to attract the attention of the females.

An iguana’s courtship method is fun to watch! Image via Ryan Hyde/ Unsplash.

Although they prefer to live among tree branches, you can also see iguanas on land and in water. During the gestation period, females dig very deep tunnels to deposit their eggs and keep them safe from predators. The tunnels can measure up to 80 inches (2 meters) deep. Although they lay between 20 and 60 eggs, not all of them hatch. Some species can lay up to 80 eggs.

Iguanas are very calm animals, except during mating seasons, when males are more territorial. If they are not used to human contact, they can be a little aggressive. In fact, they use their tail as a defensive weapon to whip their enemies. But they won’t use it if you don’t approach them, because iguanas are skittish animals that prefer to run away and avoid problems.

When iguanas are adults, you can easily distinguish their sex. Males are much larger and more robust than females. In addition, males have more developed structures, such as the femoral pores and frontal lobes (the big protuberances under each side of their mouths).

Iguanas can communicate with each other in many ways. The most interesting is through pheromones that are released thanks to the femoral pores. These are modified scales found on the thighs of iguanas. The rubbing of the pores on the ground leaves aromas that alert other iguanas to the presence of a dominant male or female.

It’s easy to distinguish males from females. Image via Surya Fajri Alfitra/ Unsplash.

The history of iguanas

The first formal record of iguanas was in 1768, in a book by the Austrian zoologist and naturalist Nicolaus Laurenti. However, it is estimated that iguanas have lived on Earth for a long, long time. Iguana fossils have been found that date back about 75 million years, meaning that they lived in the Cretaceous period in South America.

But, although both iguanas and dinosaurs are reptiles, they belong to reptile branches distant from each other, so iguanas don’t descend from dinosaurs, even though the may look like mini versions of dinos!

Are iguanas descendants of dinosaurs? Image via Firnanda Amar/ Unsplash.

Bottom line: Iguanas are formidable, armored reptiles that can change color and detach their tails. Plus, they have a third eye! All you need to know about iguanas, here.

Read more lifeform of the week articles

The post Colorful iguanas are our lifeform of the week first appeared on EarthSky.

from EarthSky https://ift.tt/Ku4qfZW

Watch a video about iguanas, our lifeform of the week!

Iguanas are reptiles that resemble miniature dinosaurs. Did you know they can change colors or detach their tails? Or that iguanas have a third eye? Read on to discover more cool facts about these curious animals.

Meet the iguanas

Iguanas are reptiles that measure between 20 inches (50 cm) and 80 inches (2 m) long from head to tail. Their hind legs are considerably larger than their front legs. But on all four legs, they have quite strong claws that allow them to climb trees without falling. Plus, they can survive falls up to 50 feet (15 m) high. This ability is important because they live among tree branches.

In fact, despite their formidable appearance and sharp teeth, iguanas are herbivorous, or plant eaters. They feed mainly on leaves, flowers and fruits. Much of their water intake comes from the plants and flowers they eat. And no, they don’t eat insects. These reptiles usually live between 10 to 20 years.

These cold-blooded animals need heat and sun to survive. That’s why they usually live in temperate or hot climates and love to sunbathe. Furthermore, sunbathing is not a whim but a necessity. Among other things, sunlight gives iguanas the vitamin D they need to absorb enough calcium.

Iguanas live among tree branches and eat leaves, flowers and fruits. Image via Joanna Borkowska/ Unsplash.

Anatomy

The extra skin under an iguana’s head is called the dewlap. It helps regulate an iguana’s temperature. And the spikes on the back and tail function as a solar collector that provides a greater surface area for absorbing heat and ultraviolet rays. Thus, iguanas stay warm longer and more effectively.

These reptiles have incredible eyesight that allow them to see colors, shadows and shapes from a long distance. In turn, that helps them anticipate predators, since their hearing is not the best. And they have well-developed lungs and breathe air just like humans.

Iguanas have a longer middle digit on their hind legs, which they use to climb trees. And they can use the tail for defense, to swim or as a stabilizer when jumping or climbing trees. In fact, iguanas are excellent swimmers. It’s hard to believe, but there are marine iguanas capable of diving for almost half an hour. These iguanas have the ability to forage in the sea for algae, which makes up almost all their diet.

Iguanas have spikes on their backs and tails to provide a greater surface area for absorbing heat and ultraviolet rays. Image via Orlando Madrigal/ Unsplash.

Colors

Iguanas have skin covered in small scales with the ability to change color. They use this ability to blend in with their environment and to hide from their predators. For example, the females can then go unnoticed when pregnant. But they can also change color to attract attention during heat. If an iguana is stressed or sick, it will change its color to dark shades.

You can find iguanas with a multitude of colors such as green, orange, yellow, purple, blue, white, black and red. And there are iguanas that have a combination of colors.

A blue iguana. Image via Anthony/ Unsplash.

A black and white iguana. Image via Andrés Oropeza/ Unsplash.

Some iguanas have a combination of different colors. Image via Alex Williams/ Unsplash.

Skin and tail

Between the hard scales iguanas have quite flexible skin. Therefore, they have both protection and agility. Additionally, iguanas shed their skin.

Iguanas can detach their own tail. This is a defense mechanism called caudal autotomy that many lizards have. When a predator chases or catches them, these animals have the ability to get rid of their tail. Would you believe the tail remains moving for a few minutes on the ground or in the predator’s mouth? This distraction allows the lizard to escape.

Their tails come off, but they can also regenerate them. The new tail grows at a rate of approximately 0.2 inches (0.5 cm) per day. But it won’t be the same as the original tail. The texture is rougher and also has a more opaque color than the original. The new tail is shorter and the scales are smaller and irregularly placed. In fact, the ridge of spines on iguanas won’t regenerate. And if there is any color pattern or drawing, it is generally altered.

Iguanas have various fat reserves in their body, and one of them is the tail, which functions as both an energy reserve and to produce some hormones that function for their reproduction. So, although they can detach their tail, it’s best that this doesn’t happen, since infections can also occur until the wound heals.

Iguanas can detach and then regenerate their tails. Image via Michael Payne/ Unsplash.

The third eye

Just like in Lord of the Rings, iguanas also have an all-seeing eye. Just kidding, it doesn’t see it all! But it is true that in addition to their two regular eyes, iguanas have a third eye located on the top of their head. It’s known as parietal eye. And iguanas use them to more accurately detect prey and predators approaching from above. Many amphibians also possess this third eye.

This organ is a modified scale that functions as a light receptor to detect some predators. It can even help the animal know what time of year it is and regulate some physiological processes such as reproduction.

Iguanas have a 3rd eye. Image via Nick Karvounis/ Unsplash.

Behavior of iguanas

Iguanas are solitary animals; they only get together in groups during mating seasons. During this time, a group of females gathers around a single male.

Something very curious about iguanas is their courtship method. In this process, male iguanas move their head (and dewlap) up and down as if to say “Yes, I mean you,” while moving their tail to attract the attention of the females.

An iguana’s courtship method is fun to watch! Image via Ryan Hyde/ Unsplash.

Although they prefer to live among tree branches, you can also see iguanas on land and in water. During the gestation period, females dig very deep tunnels to deposit their eggs and keep them safe from predators. The tunnels can measure up to 80 inches (2 meters) deep. Although they lay between 20 and 60 eggs, not all of them hatch. Some species can lay up to 80 eggs.

Iguanas are very calm animals, except during mating seasons, when males are more territorial. If they are not used to human contact, they can be a little aggressive. In fact, they use their tail as a defensive weapon to whip their enemies. But they won’t use it if you don’t approach them, because iguanas are skittish animals that prefer to run away and avoid problems.

When iguanas are adults, you can easily distinguish their sex. Males are much larger and more robust than females. In addition, males have more developed structures, such as the femoral pores and frontal lobes (the big protuberances under each side of their mouths).

Iguanas can communicate with each other in many ways. The most interesting is through pheromones that are released thanks to the femoral pores. These are modified scales found on the thighs of iguanas. The rubbing of the pores on the ground leaves aromas that alert other iguanas to the presence of a dominant male or female.

It’s easy to distinguish males from females. Image via Surya Fajri Alfitra/ Unsplash.

The history of iguanas

The first formal record of iguanas was in 1768, in a book by the Austrian zoologist and naturalist Nicolaus Laurenti. However, it is estimated that iguanas have lived on Earth for a long, long time. Iguana fossils have been found that date back about 75 million years, meaning that they lived in the Cretaceous period in South America.

But, although both iguanas and dinosaurs are reptiles, they belong to reptile branches distant from each other, so iguanas don’t descend from dinosaurs, even though the may look like mini versions of dinos!

Are iguanas descendants of dinosaurs? Image via Firnanda Amar/ Unsplash.

Bottom line: Iguanas are formidable, armored reptiles that can change color and detach their tails. Plus, they have a third eye! All you need to know about iguanas, here.

Read more lifeform of the week articles

The post Colorful iguanas are our lifeform of the week first appeared on EarthSky.

from EarthSky https://ift.tt/Ku4qfZW

Spica, the bright beacon of Virgo, is 2 stars

Even though our eyes see the star Spica as 1 star, it’s really at least 2. And we see it as distinctly blue-white. Photo by Fred Espenak at AstroPixels. Used with permission.

Spica is a close double star

The star Spica – aka Alpha Virginis – is the brightest star in the constellation Virgo the Maiden. From a distance of about 250 light-years, Spica appears to us on Earth as a lone bluish-white star in a quiet region of the sky. But Spica consists of two stars and maybe more. Both stars are larger and hotter than our sun. And they’re separated by only 11 million miles (less than 18 million km), in contrast to Earth’s distance from our sun of 93 million miles (150 million km). They orbit their common center of gravity in only four days.

We say that Earth is 1 astronomical unit (aka 1 AU) from our sun. Spica’s two stars are only .12 AU from each other, a small fraction of the Earth-sun distance.

And the two stars in the Spica system are individually indistinguishable from a single point of light, even with a telescope. Only the analysis of its light with a spectroscope – an instrument that splits light into its component colors – revealed the dual nature of this star.

Hot, hot, hot

Spica’s two stars are so close, and they orbit so quickly around each other, that their mutual gravity distorts each star into an egg shape. It’s thought that the pointed ends of these egg-shaped stars face each other as they whirl around.

The pair of stars are both dwarfs, brightening near the end of their lifetimes.

Spica is one of the hottest 1st-magnitude stars. The hottest of the pair is 22,400 Kelvin (about 40,000 F or 22,000 C). That’s blistering in contrast to the sun’s 5,800 Kelvin (about 10,000 F or 5,500 C). This star might someday explode as a supernova.

The light from Spica’s two stars, taken together, is on average more than 12,100 times brighter than our sun’s light. Their estimated diameters are 7.8 and 4 times our sun’s diameter.

Spica is one of several bright stars that the moon can occult (eclipse). Furthermore, based on observations of how the star’s light is extinguished when the moon passes in front, some astronomers think that it may not just be a spectroscopic binary star. Instead, they feel that there may be as many as three other stars in the system. In that case, Spica would not be a single or even a double star, but a quintuple star!

How to find Spica

The best evening views of Spica come from northern spring to late northern summer, when this star arcs across the southern sky in the evening. So in the month of May, as seen from the Northern Hemisphere, you’ll find Spica in the southeast in early evening. Then, from the Southern Hemisphere, Spica is closer to due east. From all of Earth in May, as night passes, Spica appears to move westward. Spica rises earlier each evening so that – by the end of August – Spica can be viewed only briefly in the west to west-southwest sky as darkness falls.

At least there’s a foolproof way to find Spica, using the Big Dipper as a guide. Scouts and stargazers remember this trick with the saying: Follow the arc to Arcturus, and speed on (or drive a spike) to Spica.

Look for the Big Dipper

First, look for the Big Dipper in the northern sky. It’s highest in the evening sky in the northern spring and summer. Notice that the Big Dipper has a bowl and a long, curved handle. Follow the arc of the Dipper’s handle outward, away from the Dipper’s bowl. The first bright star you come to is orange Arcturus. Then drive a spike (or speed on) along this curving path. And the next bright star you come to is Spica.

Spica shines at magnitude 1.04, making it the brightest light in Virgo. In fact, it’s the 15th-brightest star visible from anywhere on Earth. It’s virtually the same brightness as Antares in the constellation Scorpius, so sometimes Antares is listed as the 15th and Spica as the 16th brightest.

In northern spring, look northeast to southeast in the evening. You’ll find the Big Dipper in the northeast evening sky. Then, follow the arc to Arcturus, and drive a spike (speed on) to Spica.

In northern summer, look northwest to southwest. You’ll find the Big Dipper in the northwest evening sky. But you can still follow the arc to Arcturus, and drive a spike (speed on) to Spica.

History and mythology of Spica

The name Spica is from the Latin word for “ear” (of grain). The general connotation is that Spica refers to an “ear of wheat.” Indeed, the star and the constellation Virgo itself were sometimes associated with the Greek goddess of the harvest, Demeter.

There are many names and stories for Spica’s constellation – Virgo – in mythology, and by association with Spica as well. Fewer stories refer to Spica independently. Many classical references refer to Virgo’s stars as a goddess or with some association with wheat or the harvest, since the sun passes through Virgo in the fall. In Greece and Rome she typically was Astraea, the very personification of Justice; or Persephone, daughter of Demeter. In Egypt, Virgo was identified with Isis, and Spica was considered her lute bearer. In ancient China, Spica was a special star of spring known as the Horn.

One Arabic name was Azimech, derived from words meaning Defenseless One or Solitary One. This title may be in reference to Spica’s solitary status with no other bright stars nearby. But Spica is not the most solitary star. That honor goes to Fomalhaut, sometimes called the Autumn Star.

Spica’s position is RA: 13h 25m 12s, dec: -11° 09′ 41″

Here’s a classical illustration of the constellation Virgo the Maiden, with Spica embedded in the wheat in her left hand. Image via Urania’s Mirror/ Wikipedia.

Bottom line: Spica is the brightest star in Virgo. Spica is at least two stars orbiting extremely close together, distorting each other into egg shapes.

Virgo the Maiden represents a harvest goddess

The post Spica, the bright beacon of Virgo, is 2 stars first appeared on EarthSky.

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Even though our eyes see the star Spica as 1 star, it’s really at least 2. And we see it as distinctly blue-white. Photo by Fred Espenak at AstroPixels. Used with permission.

Spica is a close double star

The star Spica – aka Alpha Virginis – is the brightest star in the constellation Virgo the Maiden. From a distance of about 250 light-years, Spica appears to us on Earth as a lone bluish-white star in a quiet region of the sky. But Spica consists of two stars and maybe more. Both stars are larger and hotter than our sun. And they’re separated by only 11 million miles (less than 18 million km), in contrast to Earth’s distance from our sun of 93 million miles (150 million km). They orbit their common center of gravity in only four days.

We say that Earth is 1 astronomical unit (aka 1 AU) from our sun. Spica’s two stars are only .12 AU from each other, a small fraction of the Earth-sun distance.

And the two stars in the Spica system are individually indistinguishable from a single point of light, even with a telescope. Only the analysis of its light with a spectroscope – an instrument that splits light into its component colors – revealed the dual nature of this star.

Hot, hot, hot

Spica’s two stars are so close, and they orbit so quickly around each other, that their mutual gravity distorts each star into an egg shape. It’s thought that the pointed ends of these egg-shaped stars face each other as they whirl around.

The pair of stars are both dwarfs, brightening near the end of their lifetimes.

Spica is one of the hottest 1st-magnitude stars. The hottest of the pair is 22,400 Kelvin (about 40,000 F or 22,000 C). That’s blistering in contrast to the sun’s 5,800 Kelvin (about 10,000 F or 5,500 C). This star might someday explode as a supernova.

The light from Spica’s two stars, taken together, is on average more than 12,100 times brighter than our sun’s light. Their estimated diameters are 7.8 and 4 times our sun’s diameter.

Spica is one of several bright stars that the moon can occult (eclipse). Furthermore, based on observations of how the star’s light is extinguished when the moon passes in front, some astronomers think that it may not just be a spectroscopic binary star. Instead, they feel that there may be as many as three other stars in the system. In that case, Spica would not be a single or even a double star, but a quintuple star!

How to find Spica

The best evening views of Spica come from northern spring to late northern summer, when this star arcs across the southern sky in the evening. So in the month of May, as seen from the Northern Hemisphere, you’ll find Spica in the southeast in early evening. Then, from the Southern Hemisphere, Spica is closer to due east. From all of Earth in May, as night passes, Spica appears to move westward. Spica rises earlier each evening so that – by the end of August – Spica can be viewed only briefly in the west to west-southwest sky as darkness falls.

At least there’s a foolproof way to find Spica, using the Big Dipper as a guide. Scouts and stargazers remember this trick with the saying: Follow the arc to Arcturus, and speed on (or drive a spike) to Spica.

Look for the Big Dipper

First, look for the Big Dipper in the northern sky. It’s highest in the evening sky in the northern spring and summer. Notice that the Big Dipper has a bowl and a long, curved handle. Follow the arc of the Dipper’s handle outward, away from the Dipper’s bowl. The first bright star you come to is orange Arcturus. Then drive a spike (or speed on) along this curving path. And the next bright star you come to is Spica.

Spica shines at magnitude 1.04, making it the brightest light in Virgo. In fact, it’s the 15th-brightest star visible from anywhere on Earth. It’s virtually the same brightness as Antares in the constellation Scorpius, so sometimes Antares is listed as the 15th and Spica as the 16th brightest.

In northern spring, look northeast to southeast in the evening. You’ll find the Big Dipper in the northeast evening sky. Then, follow the arc to Arcturus, and drive a spike (speed on) to Spica.

In northern summer, look northwest to southwest. You’ll find the Big Dipper in the northwest evening sky. But you can still follow the arc to Arcturus, and drive a spike (speed on) to Spica.

History and mythology of Spica

The name Spica is from the Latin word for “ear” (of grain). The general connotation is that Spica refers to an “ear of wheat.” Indeed, the star and the constellation Virgo itself were sometimes associated with the Greek goddess of the harvest, Demeter.

There are many names and stories for Spica’s constellation – Virgo – in mythology, and by association with Spica as well. Fewer stories refer to Spica independently. Many classical references refer to Virgo’s stars as a goddess or with some association with wheat or the harvest, since the sun passes through Virgo in the fall. In Greece and Rome she typically was Astraea, the very personification of Justice; or Persephone, daughter of Demeter. In Egypt, Virgo was identified with Isis, and Spica was considered her lute bearer. In ancient China, Spica was a special star of spring known as the Horn.

One Arabic name was Azimech, derived from words meaning Defenseless One or Solitary One. This title may be in reference to Spica’s solitary status with no other bright stars nearby. But Spica is not the most solitary star. That honor goes to Fomalhaut, sometimes called the Autumn Star.

Spica’s position is RA: 13h 25m 12s, dec: -11° 09′ 41″

Here’s a classical illustration of the constellation Virgo the Maiden, with Spica embedded in the wheat in her left hand. Image via Urania’s Mirror/ Wikipedia.

Bottom line: Spica is the brightest star in Virgo. Spica is at least two stars orbiting extremely close together, distorting each other into egg shapes.

Virgo the Maiden represents a harvest goddess

The post Spica, the bright beacon of Virgo, is 2 stars first appeared on EarthSky.

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Crepuscular rays are sunbeams in twilight skies

View at EarthSky Community Photos. | Juliana Karoway at Lake Quinsigamond, Shrewsbury, Massachusetts, captured this image on May 14, 2024. Juliana wrote: “Can you please tell me something about these clouds? I’ve never seen a sunset like this before!” Gladly, Juliana, and thanks for sharing! These are crepuscular rays, sunbeams you can see in twilight skies thanks to small particles in the air. Read on to find out more about them.

What are crepuscular rays?

Crepuscular means resembling twilight or dim. This phenomenon occurs around sunrise or sunset, when the sun is below the horizon. And you can also see crepuscular rays when the sun is hiding behind clouds. They’re more noticeable when the sky is a bit darker and there is greater contrast between dark and light. We can see the rays of light thanks to dust, smoke or water droplets that scatter the light toward our eyes.

The darker streaks beside the sunbeams are due to shadows, where the terrain or clouds block the sunlight from coming through. Sometimes those obstructions are below the horizon from your point of view, so it may not seem immediately clear what’s causing the darker rays.

When crepuscular rays extend from behind a cloud toward the ground, they also go by the nickname Jacob’s Ladder. The term comes from a story in the Bible where Jacob has a dream in which he sees a ladder leading up to the golden light of heaven with angels ascending and descending.

Parallel lines that seem to converge

Crepuscular rays appear to fan across the sky. But these sunbeams are really parallel to each other. In fact, sometimes you can trace them all the way across the sky to the point on the horizon opposite the sunset. So, the next time you see them, remember to turn around. You might spot the fainter and less noticeable anticrepuscular rays. The illusion is similar to standing on train tracks and seeing how they appear to converge in the far distance in front of and behind you.

View at EarthSky Community Photos. | Ron Haggett in Yuma, Arizona, captured crepuscular rays (left) and anticrepuscular rays (right) on the morning of September 1, 2021. He wrote: “These photos were taken 9 minutes apart (6:00 and 6:09 a.m., local time). The image on the left is looking east before sunrise. Sunbeams can also extend across the sky and appear to converge at the antisolar point, the point on the celestial sphere opposite the sun’s direction. In this case, they’re called antisolar rays. The image on the right is at the antisolar point (due west).” Thank you, Ron!

View at EarthSky Community Photos. | Brendan Barnes captured crepuscular rays running all the way across the sky in this panoramic photo taken in Guam on October 28, 2020. He wrote: “I woke up this morning to bright pink clouds outside my window, so I ran upstairs to the roof and found crepuscular rays going the entire way from the rising sun toward the horizon to the west!” Thank you, Brendan!

Photo gallery of crepuscular rays

All of these photos were contributed by EarthSky friends. Thanks for sharing your awesome photos with us! Would you like to contribute? Submit your image here.

View at Earthsky Community Photos. | Guy Newlan in Orlando, Florida, captured this image on August 19, 2023. He wrote: “A cirrocumulus layer was an excellent screen for pre-sunrise crepuscular rays.” Thanks, Guy!

View at EarthSky Community Photos. | Jenney Disimon captured these crepuscular rays in Sabah, North Borneo, Malaysia, on April 19, 2023. Jenney wrote: “On waking up, this was what I first saw. Crepuscular rays as the background of the iconic Mt. Kinabalu at dawn. And somewhere hidden was the old crescent moon. What an awesome sight!” Thank you!

View at EarthSky Community Photos. | Helio C. Vital in Rio de Janeiro, Brazil, took this photo on March 1, 2023. Helio wrote: “The photo shows Jupiter and Venus only 35 arcminutes apart in the midst of bright crepuscular rays. Thank you!

Moon rays or moonbeams

James Younger frequently camps at Vancouver Island and catches many wonderful sky sights from its shores. He captured these moon rays (in the clouds above) in August 2017.

Bottom line: Crepuscular rays are shadows in the sky of distant terrain or clouds. They form around twilight when particles in the atmosphere reflect the sun’s light beams toward our eyes. Sometimes you can see anticrepuscular rays on the horizon opposite the sun.

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The post Crepuscular rays are sunbeams in twilight skies first appeared on EarthSky.

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View at EarthSky Community Photos. | Juliana Karoway at Lake Quinsigamond, Shrewsbury, Massachusetts, captured this image on May 14, 2024. Juliana wrote: “Can you please tell me something about these clouds? I’ve never seen a sunset like this before!” Gladly, Juliana, and thanks for sharing! These are crepuscular rays, sunbeams you can see in twilight skies thanks to small particles in the air. Read on to find out more about them.

What are crepuscular rays?

Crepuscular means resembling twilight or dim. This phenomenon occurs around sunrise or sunset, when the sun is below the horizon. And you can also see crepuscular rays when the sun is hiding behind clouds. They’re more noticeable when the sky is a bit darker and there is greater contrast between dark and light. We can see the rays of light thanks to dust, smoke or water droplets that scatter the light toward our eyes.

The darker streaks beside the sunbeams are due to shadows, where the terrain or clouds block the sunlight from coming through. Sometimes those obstructions are below the horizon from your point of view, so it may not seem immediately clear what’s causing the darker rays.

When crepuscular rays extend from behind a cloud toward the ground, they also go by the nickname Jacob’s Ladder. The term comes from a story in the Bible where Jacob has a dream in which he sees a ladder leading up to the golden light of heaven with angels ascending and descending.

Parallel lines that seem to converge

Crepuscular rays appear to fan across the sky. But these sunbeams are really parallel to each other. In fact, sometimes you can trace them all the way across the sky to the point on the horizon opposite the sunset. So, the next time you see them, remember to turn around. You might spot the fainter and less noticeable anticrepuscular rays. The illusion is similar to standing on train tracks and seeing how they appear to converge in the far distance in front of and behind you.

View at EarthSky Community Photos. | Ron Haggett in Yuma, Arizona, captured crepuscular rays (left) and anticrepuscular rays (right) on the morning of September 1, 2021. He wrote: “These photos were taken 9 minutes apart (6:00 and 6:09 a.m., local time). The image on the left is looking east before sunrise. Sunbeams can also extend across the sky and appear to converge at the antisolar point, the point on the celestial sphere opposite the sun’s direction. In this case, they’re called antisolar rays. The image on the right is at the antisolar point (due west).” Thank you, Ron!

View at EarthSky Community Photos. | Brendan Barnes captured crepuscular rays running all the way across the sky in this panoramic photo taken in Guam on October 28, 2020. He wrote: “I woke up this morning to bright pink clouds outside my window, so I ran upstairs to the roof and found crepuscular rays going the entire way from the rising sun toward the horizon to the west!” Thank you, Brendan!

Photo gallery of crepuscular rays

All of these photos were contributed by EarthSky friends. Thanks for sharing your awesome photos with us! Would you like to contribute? Submit your image here.

View at Earthsky Community Photos. | Guy Newlan in Orlando, Florida, captured this image on August 19, 2023. He wrote: “A cirrocumulus layer was an excellent screen for pre-sunrise crepuscular rays.” Thanks, Guy!

View at EarthSky Community Photos. | Jenney Disimon captured these crepuscular rays in Sabah, North Borneo, Malaysia, on April 19, 2023. Jenney wrote: “On waking up, this was what I first saw. Crepuscular rays as the background of the iconic Mt. Kinabalu at dawn. And somewhere hidden was the old crescent moon. What an awesome sight!” Thank you!

View at EarthSky Community Photos. | Helio C. Vital in Rio de Janeiro, Brazil, took this photo on March 1, 2023. Helio wrote: “The photo shows Jupiter and Venus only 35 arcminutes apart in the midst of bright crepuscular rays. Thank you!

Moon rays or moonbeams

James Younger frequently camps at Vancouver Island and catches many wonderful sky sights from its shores. He captured these moon rays (in the clouds above) in August 2017.

Bottom line: Crepuscular rays are shadows in the sky of distant terrain or clouds. They form around twilight when particles in the atmosphere reflect the sun’s light beams toward our eyes. Sometimes you can see anticrepuscular rays on the horizon opposite the sun.

Enjoying EarthSky? Sign up for our free daily newsletter today!

The post Crepuscular rays are sunbeams in twilight skies first appeared on EarthSky.

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Giant hummingbirds with backpacks help discover a species

Researchers from UNM’s Museum of Southwestern Biology (MSB) in Albuquerque, New Mexico, wanted to know what happens with giant hummingbirds during winter. These birds breed along the Pacific Coast of central Chile, but after that, they just disappear.

Thanks to a tiny backpack adapted for these birds, the team was able to follow them until they were super high in the Andes! And not only that, this study led them to the discovery of a new species of hummingbird that inhabits the Andes. You can read the full study, published on May 13, 2024, at the National Library of Medicine.

Giant hummingbirds, tiny backpacks

Here’s a giant hummingbird with a geo-locator backpack, in the Valparaíso region of Chile. These giant hummingbirds helped discover a new species. Image via Chris Witt/ University of New Mexico/ Museum of Southwestern Biology.

The group of researchers found some great assistants for their eight-year-long study. These assistants have feathers, are colorful, move really fast and are tougher than some might think. They are giant hummingbirds!

The team, led by ornithologist Jessie Williamson, wanted to study the migratory habits of giant hummingbirds, as they breed along the Pacific coasts of central Chile and seemingly vanish after breeding. The last clue they had came from Charles Darwin, who in the 19th century speculated they migrated to the Atacama Desert region of northern Chile.

But, how to track them? The team decided to create tiny backpacks that would fit them. Even though giant hummingbirds are the largest kind of hummingbird, they are still only up to 10 inches (25 cm) long. So, their backpacks had to be small and light enough that they wouldn’t interfere with the birds’ hovering style of flight. Williamson wrote:

It took a lot of trial and error to come up with a suitable harness design. Hummingbirds are challenging to work with because they are lightweight with long wings and short legs. They’re nature’s tiny acrobats.

A long flight to the Andes

The team discovered that migratory giant hummingbirds can ascend over 13,000 feet (4 km) in elevation to the high Andes. If you know about the Andes flight disaster that occurred at the Andes in 1972, you know that this environment is extremely rough. This is why hummingbirds employ the same acclimatization strategy used by professional mountaineers. They don’t fly straight up to high altitudes; they pause their upward climb for periods of days to allow their blood and lungs to acclimatize.

These birds can fly as far north as the mountains of Peru. The roundtrip journey covers more than 5,200 miles (8,370 km). As comparison, that’s the distance between New York City and Buenos Aires in Argentina. It’s one of the longest, if not the longest hummingbird migration in the world.

Map of the Andes, the longest continental mountain range in the world. The Andes extend from north to south through 7 South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina. Image via Carlos A Arango / Wikipedia (public domain).

Finding of a new species

At first, the research goal was simply to learn where the migratory population went. But it also led to a fascinating discovery:

It turns out that in the Andes there are not one, but two groups of giant hummingbirds. The northern population stays in the high Andes year-round, while the southern population migrates from sea level up to 13,000 feet (4,000 m) during the non-breeding months. The two species overlap their stays at the high elevation wintering grounds.

Christopher Witt, Professor and Director of the Museum of Southwestern Biology, wrote:

Nobody had figured out where migratory giant hummingbirds go because they were hiding among the non-migratory giant hummingbirds. The two forms of giant hummingbird look almost identical. For centuries, ornithologists and birders never noticed that they were different. We couldn’t have figured this out without the miniaturized trackers.

2 species of giant hummingbird

After the discovery, the team did further research to learn more about how different these species are, and to understand how they evolved until they became two different species. Co-author Ethan Gyllenhaal wrote:

Natural history collections were absolutely essential to this work. Including DNA from 154-year-old type specimens was key to solving this evolutionary puzzle.

The authors say the shift in migratory behavior is what drove speciation. It seems that the migratory and high-elevation resident giant hummingbirds had been evolving separately for about 3 million years! The hummingbirds that live in the high Andes year-round are larger and have notably different blood and lungs.

Now, the researchers are proposing names to differentiate these two species … Any cool names come to your mind?

Bottom line: Giant hummingbirds with tiny backpacks helped discover a new species of hummingbird, as they were tracked up high in the Andes.

Sources: How miniature backpacks led to the discovery of the world’s largest hummingbird species

Via National Library of Medicine: Extreme elevational migration spurred cryptic speciation in giant hummingbirds

Read more: Hummingbirds, tiny and colorful: Lifeform of the week

The post Giant hummingbirds with backpacks help discover a species first appeared on EarthSky.

from EarthSky https://ift.tt/Wtj645u

Researchers from UNM’s Museum of Southwestern Biology (MSB) in Albuquerque, New Mexico, wanted to know what happens with giant hummingbirds during winter. These birds breed along the Pacific Coast of central Chile, but after that, they just disappear.

Thanks to a tiny backpack adapted for these birds, the team was able to follow them until they were super high in the Andes! And not only that, this study led them to the discovery of a new species of hummingbird that inhabits the Andes. You can read the full study, published on May 13, 2024, at the National Library of Medicine.

Giant hummingbirds, tiny backpacks

Here’s a giant hummingbird with a geo-locator backpack, in the Valparaíso region of Chile. These giant hummingbirds helped discover a new species. Image via Chris Witt/ University of New Mexico/ Museum of Southwestern Biology.

The group of researchers found some great assistants for their eight-year-long study. These assistants have feathers, are colorful, move really fast and are tougher than some might think. They are giant hummingbirds!

The team, led by ornithologist Jessie Williamson, wanted to study the migratory habits of giant hummingbirds, as they breed along the Pacific coasts of central Chile and seemingly vanish after breeding. The last clue they had came from Charles Darwin, who in the 19th century speculated they migrated to the Atacama Desert region of northern Chile.

But, how to track them? The team decided to create tiny backpacks that would fit them. Even though giant hummingbirds are the largest kind of hummingbird, they are still only up to 10 inches (25 cm) long. So, their backpacks had to be small and light enough that they wouldn’t interfere with the birds’ hovering style of flight. Williamson wrote:

It took a lot of trial and error to come up with a suitable harness design. Hummingbirds are challenging to work with because they are lightweight with long wings and short legs. They’re nature’s tiny acrobats.

A long flight to the Andes

The team discovered that migratory giant hummingbirds can ascend over 13,000 feet (4 km) in elevation to the high Andes. If you know about the Andes flight disaster that occurred at the Andes in 1972, you know that this environment is extremely rough. This is why hummingbirds employ the same acclimatization strategy used by professional mountaineers. They don’t fly straight up to high altitudes; they pause their upward climb for periods of days to allow their blood and lungs to acclimatize.

These birds can fly as far north as the mountains of Peru. The roundtrip journey covers more than 5,200 miles (8,370 km). As comparison, that’s the distance between New York City and Buenos Aires in Argentina. It’s one of the longest, if not the longest hummingbird migration in the world.

Map of the Andes, the longest continental mountain range in the world. The Andes extend from north to south through 7 South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina. Image via Carlos A Arango / Wikipedia (public domain).

Finding of a new species

At first, the research goal was simply to learn where the migratory population went. But it also led to a fascinating discovery:

It turns out that in the Andes there are not one, but two groups of giant hummingbirds. The northern population stays in the high Andes year-round, while the southern population migrates from sea level up to 13,000 feet (4,000 m) during the non-breeding months. The two species overlap their stays at the high elevation wintering grounds.

Christopher Witt, Professor and Director of the Museum of Southwestern Biology, wrote:

Nobody had figured out where migratory giant hummingbirds go because they were hiding among the non-migratory giant hummingbirds. The two forms of giant hummingbird look almost identical. For centuries, ornithologists and birders never noticed that they were different. We couldn’t have figured this out without the miniaturized trackers.

2 species of giant hummingbird

After the discovery, the team did further research to learn more about how different these species are, and to understand how they evolved until they became two different species. Co-author Ethan Gyllenhaal wrote:

Natural history collections were absolutely essential to this work. Including DNA from 154-year-old type specimens was key to solving this evolutionary puzzle.

The authors say the shift in migratory behavior is what drove speciation. It seems that the migratory and high-elevation resident giant hummingbirds had been evolving separately for about 3 million years! The hummingbirds that live in the high Andes year-round are larger and have notably different blood and lungs.

Now, the researchers are proposing names to differentiate these two species … Any cool names come to your mind?

Bottom line: Giant hummingbirds with tiny backpacks helped discover a new species of hummingbird, as they were tracked up high in the Andes.

Sources: How miniature backpacks led to the discovery of the world’s largest hummingbird species

Via National Library of Medicine: Extreme elevational migration spurred cryptic speciation in giant hummingbirds

Read more: Hummingbirds, tiny and colorful: Lifeform of the week

The post Giant hummingbirds with backpacks help discover a species first appeared on EarthSky.

from EarthSky https://ift.tt/Wtj645u

The Northern Crown is a beautiful star pattern in May

Corona Borealis, the Northern Crown, with its brightest star Alphecca. In fact, this time of the year is perfect to see this semicircle of stars in the evening sky. Image via Fred Espenak/ AstroPixels. Used with permission.

The Northern Crown graces the summer skies

Tonight, look for a constellation that’s easy to see on the sky’s dome, if your sky is dark enough. Corona Borealis – aka the Northern Crown – is exciting to find. In fact, it’s easy to pick out as an almost-perfect semicircle of stars. You’ll find this beautiful star pattern in the evening sky from now until October.

Plus, the constellation Corona Borealis is easy to find since it’s located more or less along a line between two bright stars. The first is Arcturus in the constellation Boötes the Herdsman and the second is Vega in the constellation Lyra the Harp.

After nightfall and in the early evening, you’ll see Arcturus fairly high in the east, noticeable for its brightness and yellow-orange color. Next, look for Vega rather low in the northeast. It’s a bright blue-white star. Then look for the Northern Crown between these 2 bright stars. It’s a bit closer to Arcturus.

However, you’ll need a fairly dark sky to clearly see Corona Borealis between Vega and Arcturus. Then, once you find the semicircle of stars, it’s very noticeable.

The brightest star of the Northern Crown

The brightest star in Corona Borealis is Alphecca, also known as Gemma, sometimes called the Pearl of the Crown. The name Alphecca originated with a description of Corona Borealis as the “broken one.” This was in reference to the fact that these stars appear in a semicircle, rather than a full circle. Alphecca is a blue-white star, with an intrinsic luminosity some 60 times that of our sun. It’s located about 75 light-years from Earth.

The C-shaped – or semicircle – constellation Corona Borealis shines between the constellations Boötes and Hercules. Image via IAU. Used with permission.

Watch for a ‘new star’ in the Northern Crown

T Coronae Borealis, or T CrB, is located 3,000 light-years away from Earth. It is a recurring nova with outbursts about every 80 years. Its last outburst was in 1946, and astronomers believe another will occur between February and September 2024.

The star system, normally of magnitude +10, is far too dim to see with the unaided eye. When the nova occurs, it will jump to around magnitude +2. That is roughly the same brightness to the North Star, Polaris.

Once its brightness peaks, it should be visible to the unaided eye for several days and just over a week with binoculars before it dims again, possibly for another 80 years.

Star chart of Corona Borealis with red circle indicating location of star T CrB. Image via IAU/ Wikipedia/ (CC BY-SA 4.0).

View at EarthSky Community Photos. | Prateek Pandey in Bhopal, Madhya Pradesh, India, captured this photo of Boötes, Virgo and Corona Borealis on March 5, 2021. He wrote: “Spring constellations twinkling in the eastern horizon.” Thank you, Prateek!

Bottom line: Look for Corona Borealis – the Northern Crown – between the brilliant stars Arcturus and Vega tonight! In fact, this constellation is very noticeable, if you have a dark sky.

Read more: A ‘new star’ from a nova outburst is expected soon

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

The post The Northern Crown is a beautiful star pattern in May first appeared on EarthSky.

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Corona Borealis, the Northern Crown, with its brightest star Alphecca. In fact, this time of the year is perfect to see this semicircle of stars in the evening sky. Image via Fred Espenak/ AstroPixels. Used with permission.

The Northern Crown graces the summer skies

Tonight, look for a constellation that’s easy to see on the sky’s dome, if your sky is dark enough. Corona Borealis – aka the Northern Crown – is exciting to find. In fact, it’s easy to pick out as an almost-perfect semicircle of stars. You’ll find this beautiful star pattern in the evening sky from now until October.

Plus, the constellation Corona Borealis is easy to find since it’s located more or less along a line between two bright stars. The first is Arcturus in the constellation Boötes the Herdsman and the second is Vega in the constellation Lyra the Harp.

After nightfall and in the early evening, you’ll see Arcturus fairly high in the east, noticeable for its brightness and yellow-orange color. Next, look for Vega rather low in the northeast. It’s a bright blue-white star. Then look for the Northern Crown between these 2 bright stars. It’s a bit closer to Arcturus.

However, you’ll need a fairly dark sky to clearly see Corona Borealis between Vega and Arcturus. Then, once you find the semicircle of stars, it’s very noticeable.

The brightest star of the Northern Crown

The brightest star in Corona Borealis is Alphecca, also known as Gemma, sometimes called the Pearl of the Crown. The name Alphecca originated with a description of Corona Borealis as the “broken one.” This was in reference to the fact that these stars appear in a semicircle, rather than a full circle. Alphecca is a blue-white star, with an intrinsic luminosity some 60 times that of our sun. It’s located about 75 light-years from Earth.

The C-shaped – or semicircle – constellation Corona Borealis shines between the constellations Boötes and Hercules. Image via IAU. Used with permission.

Watch for a ‘new star’ in the Northern Crown

T Coronae Borealis, or T CrB, is located 3,000 light-years away from Earth. It is a recurring nova with outbursts about every 80 years. Its last outburst was in 1946, and astronomers believe another will occur between February and September 2024.

The star system, normally of magnitude +10, is far too dim to see with the unaided eye. When the nova occurs, it will jump to around magnitude +2. That is roughly the same brightness to the North Star, Polaris.

Once its brightness peaks, it should be visible to the unaided eye for several days and just over a week with binoculars before it dims again, possibly for another 80 years.

Star chart of Corona Borealis with red circle indicating location of star T CrB. Image via IAU/ Wikipedia/ (CC BY-SA 4.0).

View at EarthSky Community Photos. | Prateek Pandey in Bhopal, Madhya Pradesh, India, captured this photo of Boötes, Virgo and Corona Borealis on March 5, 2021. He wrote: “Spring constellations twinkling in the eastern horizon.” Thank you, Prateek!

Bottom line: Look for Corona Borealis – the Northern Crown – between the brilliant stars Arcturus and Vega tonight! In fact, this constellation is very noticeable, if you have a dark sky.

Read more: A ‘new star’ from a nova outburst is expected soon

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The post The Northern Crown is a beautiful star pattern in May first appeared on EarthSky.

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Is AI to blame for our failure to find alien civilizations?

View at EarthSky Community Photos. | Ross Stone captured the May 10, 2024, aurora from Owens Valley Radio Observatory in Big Pine, California. Thank you, Ross! Read on to find out if AI could be the reason we’ve never detected an alien civilization.

By Michael Garrett, University of Manchester

Is AI to blame for a lack of alien civilizations?

Artificial intelligence (AI) has progressed at an astounding pace over the last few years. Some scientists are now looking toward the development of artificial superintelligence (ASI). ASI is a form of AI that would not only surpass human intelligence but would not be bound by the learning speeds of humans.

But what if this milestone isn’t just a remarkable achievement? What if it also represents a formidable bottleneck in the development of all civilizations? One so challenging that it thwarts their long-term survival?

This idea is at the heart of a research paper I recently published in Acta Astronautica. Could AI be the universe’s great filter? A threshold so hard to overcome that it prevents most life from evolving into space-faring civilizations?

This concept might explain why the search for extraterrestrial intelligence (SETI) has yet to detect the signatures of advanced technical civilizations elsewhere in the galaxy.

Attention astronomy enthusiasts! Are you looking for a way to show your support for astronomy education? Donate to EarthSky.org here and help us bring knowledge of the night sky and our universe to people worldwide.

The great filter

The great filter hypothesis is ultimately a proposed solution to the Fermi Paradox. This questions why, in a universe vast and ancient enough to host billions of potentially habitable planets, we have not detected any signs of alien civilizations. The hypothesis suggests there are insurmountable hurdles in the evolutionary timeline of civilizations. Those hurdles prevent them from developing into space-faring entities.

I believe the emergence of ASI could be such a filter. AI’s rapid advancement, potentially leading to ASI, may intersect with a critical phase in a civilization’s development: the transition from a single-planet species to a multiplanetary one.

This is where many civilizations could falter. AI could make much more rapid progress than our ability either to control it or sustainably explore and populate our solar system.

Artificial superintelligence pitfalls

The challenge with AI, and specifically ASI, lies in its autonomous, self-amplifying and improving nature. It possesses the potential to enhance its own capabilities at a speed that outpaces our own evolutionary timelines without AI.

The potential for something to go badly wrong is enormous. It could lead to the downfall of both biological and AI civilizations before they ever get the chance to become multiplanetary. For example, if nations increasingly rely on and cede power to autonomous AI systems that compete against each other. They could use those military capabilities to kill and destroy on an unprecedented scale. This could potentially lead to the destruction of our entire civilization, including the AI systems themselves.

In this scenario, I estimate the typical longevity of a technological civilization might be less than 100 years. That’s roughly the time between being able to receive and broadcast signals between the stars (1960), and the estimated emergence of ASI (2040) on Earth. This is alarmingly short when set against the cosmic timescale of billions of years.

This estimate, when plugged into optimistic versions of the Drake equation – which attempts to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way – suggests that, at any given time, there are only a handful of intelligent civilizations out there. Moreover, like us, their relatively modest technological activities could make them quite challenging to detect.

There’s a mindboggling number of planets out there. Image via NASA/ ESA/ CSA/ James Webb telescope.

AI wake-up call

This research is not simply a cautionary tale of potential doom. It serves as a wake-up call for humanity to establish robust regulatory frameworks to guide the development of AI, including military systems.

This is not just about preventing the malevolent use of AI on Earth. It’s also about ensuring the evolution of AI aligns with the long-term survival of our species. It suggests we need to put more resources into becoming a multiplanetary society as soon as possible. And that’s a goal that has lain dormant since the heady days of the Apollo project. But lately it’s been reignited by advances made by private companies.

As the historian Yuval Noah Harari noted, nothing in history has prepared us for the impact of introducing non-conscious, super-intelligent entities to our planet. Recently, the implications of autonomous AI decision-making have led to calls from prominent leaders in the field for a moratorium on the development of AI. That is, until a responsible form of control and regulation can be introduced.

But even if every country agreed to abide by strict rules and regulation, rogue organizations will be difficult to rein in.

AI in the military

The integration of autonomous AI in military defense systems has to be an area of particular concern. There is already evidence that humans will voluntarily relinquish significant power to increasingly capable systems. That’s because they can carry out useful tasks much more rapidly and effectively without human intervention. Governments are therefore reluctant to regulate in this area given the strategic advantages AI offers. And some of these examples have been recently and devastatingly demonstrated in Gaza.

This means we already edge dangerously close to a precipice where autonomous weapons operate beyond ethical boundaries and sidestep international law. In such a world, surrendering power to AI systems in order to gain a tactical advantage could inadvertently set off a chain of rapidly escalating, highly destructive events. In the blink of an eye, the collective intelligence of our planet could be obliterated.

Humanity is at a crucial point in its technological trajectory. Our actions now could determine whether we become an enduring interstellar civilization, or succumb to the challenges posed by our own creations.

Looking at AI through a SETI lens

Using SETI as a lens through which we can examine our future development adds a new dimension to the discussion on the future of AI. It is up to all of us to ensure that when we reach for the stars, we do so not as a cautionary tale for other civilizations. Instead, it should be as a beacon of hope: a species that learned to thrive alongside AI.

Michael Garrett, Sir Bernard Lovell chair of Astrophysics and Director of Jodrell Bank Centre for Astrophysics, University of Manchester

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

Bottom line: Is AI – artificial intelligence – the great filter that alien civilizations are unable to evolve beyond? The threat of AI and our own self-destruction, here.

The post Is AI to blame for our failure to find alien civilizations? first appeared on EarthSky.

from EarthSky https://ift.tt/l8X3KUm

View at EarthSky Community Photos. | Ross Stone captured the May 10, 2024, aurora from Owens Valley Radio Observatory in Big Pine, California. Thank you, Ross! Read on to find out if AI could be the reason we’ve never detected an alien civilization.

By Michael Garrett, University of Manchester

Is AI to blame for a lack of alien civilizations?

Artificial intelligence (AI) has progressed at an astounding pace over the last few years. Some scientists are now looking toward the development of artificial superintelligence (ASI). ASI is a form of AI that would not only surpass human intelligence but would not be bound by the learning speeds of humans.

But what if this milestone isn’t just a remarkable achievement? What if it also represents a formidable bottleneck in the development of all civilizations? One so challenging that it thwarts their long-term survival?

This idea is at the heart of a research paper I recently published in Acta Astronautica. Could AI be the universe’s great filter? A threshold so hard to overcome that it prevents most life from evolving into space-faring civilizations?

This concept might explain why the search for extraterrestrial intelligence (SETI) has yet to detect the signatures of advanced technical civilizations elsewhere in the galaxy.

Attention astronomy enthusiasts! Are you looking for a way to show your support for astronomy education? Donate to EarthSky.org here and help us bring knowledge of the night sky and our universe to people worldwide.

The great filter

The great filter hypothesis is ultimately a proposed solution to the Fermi Paradox. This questions why, in a universe vast and ancient enough to host billions of potentially habitable planets, we have not detected any signs of alien civilizations. The hypothesis suggests there are insurmountable hurdles in the evolutionary timeline of civilizations. Those hurdles prevent them from developing into space-faring entities.

I believe the emergence of ASI could be such a filter. AI’s rapid advancement, potentially leading to ASI, may intersect with a critical phase in a civilization’s development: the transition from a single-planet species to a multiplanetary one.

This is where many civilizations could falter. AI could make much more rapid progress than our ability either to control it or sustainably explore and populate our solar system.

Artificial superintelligence pitfalls

The challenge with AI, and specifically ASI, lies in its autonomous, self-amplifying and improving nature. It possesses the potential to enhance its own capabilities at a speed that outpaces our own evolutionary timelines without AI.

The potential for something to go badly wrong is enormous. It could lead to the downfall of both biological and AI civilizations before they ever get the chance to become multiplanetary. For example, if nations increasingly rely on and cede power to autonomous AI systems that compete against each other. They could use those military capabilities to kill and destroy on an unprecedented scale. This could potentially lead to the destruction of our entire civilization, including the AI systems themselves.

In this scenario, I estimate the typical longevity of a technological civilization might be less than 100 years. That’s roughly the time between being able to receive and broadcast signals between the stars (1960), and the estimated emergence of ASI (2040) on Earth. This is alarmingly short when set against the cosmic timescale of billions of years.

This estimate, when plugged into optimistic versions of the Drake equation – which attempts to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way – suggests that, at any given time, there are only a handful of intelligent civilizations out there. Moreover, like us, their relatively modest technological activities could make them quite challenging to detect.

There’s a mindboggling number of planets out there. Image via NASA/ ESA/ CSA/ James Webb telescope.

AI wake-up call

This research is not simply a cautionary tale of potential doom. It serves as a wake-up call for humanity to establish robust regulatory frameworks to guide the development of AI, including military systems.

This is not just about preventing the malevolent use of AI on Earth. It’s also about ensuring the evolution of AI aligns with the long-term survival of our species. It suggests we need to put more resources into becoming a multiplanetary society as soon as possible. And that’s a goal that has lain dormant since the heady days of the Apollo project. But lately it’s been reignited by advances made by private companies.

As the historian Yuval Noah Harari noted, nothing in history has prepared us for the impact of introducing non-conscious, super-intelligent entities to our planet. Recently, the implications of autonomous AI decision-making have led to calls from prominent leaders in the field for a moratorium on the development of AI. That is, until a responsible form of control and regulation can be introduced.

But even if every country agreed to abide by strict rules and regulation, rogue organizations will be difficult to rein in.

AI in the military

The integration of autonomous AI in military defense systems has to be an area of particular concern. There is already evidence that humans will voluntarily relinquish significant power to increasingly capable systems. That’s because they can carry out useful tasks much more rapidly and effectively without human intervention. Governments are therefore reluctant to regulate in this area given the strategic advantages AI offers. And some of these examples have been recently and devastatingly demonstrated in Gaza.

This means we already edge dangerously close to a precipice where autonomous weapons operate beyond ethical boundaries and sidestep international law. In such a world, surrendering power to AI systems in order to gain a tactical advantage could inadvertently set off a chain of rapidly escalating, highly destructive events. In the blink of an eye, the collective intelligence of our planet could be obliterated.

Humanity is at a crucial point in its technological trajectory. Our actions now could determine whether we become an enduring interstellar civilization, or succumb to the challenges posed by our own creations.

Looking at AI through a SETI lens

Using SETI as a lens through which we can examine our future development adds a new dimension to the discussion on the future of AI. It is up to all of us to ensure that when we reach for the stars, we do so not as a cautionary tale for other civilizations. Instead, it should be as a beacon of hope: a species that learned to thrive alongside AI.

Michael Garrett, Sir Bernard Lovell chair of Astrophysics and Director of Jodrell Bank Centre for Astrophysics, University of Manchester

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

Bottom line: Is AI – artificial intelligence – the great filter that alien civilizations are unable to evolve beyond? The threat of AI and our own self-destruction, here.

The post Is AI to blame for our failure to find alien civilizations? first appeared on EarthSky.

from EarthSky https://ift.tt/l8X3KUm