Max Planck scientists discover gene switch responsible for flight muscle formation
Flies are real flight artists, although they only have small wings compared to their body size. Scientists at the Max Planck Institute of Biochemistry in Martinsried near Munich, Germany, recently identified the genetic switch that regulates the formation of flight muscles. “The gene spalt is essential for the generation of the ultrafast super muscles,” emphasizes Frank Schnorrer, head of the research group “Muscle Dynamics”. “Without spalt, the fly builds only normal leg muscles instead of flight muscles.” The scientists’ results have now been published in Nature.
In order to fly efficiently, flies have to flap their small wings very fast. This causes the familiar buzzing and humming of the small beasts. The fruit fly Drosophila melanogaster moves her wings at a frequency of 200 hertz – that means its flight muscles contract and relax 200 times per second. “In contrast, a hundred meters sprinter who moves his legs only a few times per second moves like a snail,” Frank Schnorrer describes. How can the fruit fly flap its wings at such a high frequency?
Muscles control all body movements, including the wing oscillations. However, flight muscles are unique. Their contractions are not only regulated by nerve impulses as usual, but additionally triggered by tension. Every fly has two categories of flight muscles which enable the wing oscillations: One type moves the wings down and, at the same time, stretches the other type which induces its contraction. Such, the wings are pulled up again and stable wing oscillations begin.
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Showing posts with label flight. Show all posts
Showing posts with label flight. Show all posts
Sunday, November 20, 2011
Tuesday, November 16, 2010
Pterosaur reptile used "pole vault" trick for take-off
Some have suggested the biggest pterosaurs were incapable of flight
A new study claims that the ancient winged reptiles known as pterosaurs used a "pole-vaulting" action to take to the air.
They say the creatures took off using all four of their limbs.
The reptiles vaulted over their wings, pushing off first with their hind limbs and then thrusting themselves upwards with their powerful arm muscles - not dissimilar to some modern bats.
The research is published in the open-access journal Plos One.
Pterosaurs lived at the same time as the dinosaurs, but belonged to a different group of reptiles. They existed from the Triassic Period until the end of the Cretaceous - about 220 million years ago to 65 million years ago.
In their study, Dr Mark Witton at Portsmouth University, UK, and Dr Michael Habib of Chatham University, Pennsylvania, US, reappraised giant pterosaur fossils.
Their findings challenge other claims that the giant pterosaurs - such as Pteranodon and the largest azhdarchids - were not capable of flying.
'Too heavy'
Researchers have previously suggested that these creatures were too heavy to have taken to the skies.
There have also been doubts that the ancient reptiles could have taken off using the same action as birds.
"Most birds take off either by running to pick up speed and jumping into the air before flapping wildly, or if they're small enough, they may simply launch themselves into the air from a standstill," said Dr Witton.
"Previous theories suggested that giant pterosaurs were too big and heavy to perform either of these manoeuvres."
He added: "These creatures were not birds; they were flying reptiles with a distinctly different skeletal structure, wing proportions and muscle mass.
"They would have achieved flight in a completely different way to birds and would have had a lower angle of take off and initial flight trajectory."
Muscle bulk
The authors of the latest study suggest that, with up to 50kg of forelimb muscle, the creatures could easily have launched themselves into the air despite their massive size and weight.
Dr Habib explained: "Instead of taking off with their legs alone, like birds, pterosaurs probably took off using all four of their limbs.
"By using their arms as the main engines for launching instead of their legs, they use the flight muscles - the strongest in their bodies - to take off and that gives them potential to launch much greater weight into the air," he explained.
"When they were far enough off the ground, they could start flapping their wings before finding a thermal or another area of uplift to gain some altitude and glide off to wherever they wanted to go," he told BBC News.
The largest pterosaurs may have had wingspans up to 13m and weighed up to 544kg.
But the authors' reappraisal of pterosaur fossils suggests these numbers may have been overestimated. They argue that the biggest creatures may have had 10-11m wingspans and weighed between 200 and 250 kg.
A new study claims that the ancient winged reptiles known as pterosaurs used a "pole-vaulting" action to take to the air.
They say the creatures took off using all four of their limbs.
The reptiles vaulted over their wings, pushing off first with their hind limbs and then thrusting themselves upwards with their powerful arm muscles - not dissimilar to some modern bats.
The research is published in the open-access journal Plos One.
Pterosaurs lived at the same time as the dinosaurs, but belonged to a different group of reptiles. They existed from the Triassic Period until the end of the Cretaceous - about 220 million years ago to 65 million years ago.
In their study, Dr Mark Witton at Portsmouth University, UK, and Dr Michael Habib of Chatham University, Pennsylvania, US, reappraised giant pterosaur fossils.
Their findings challenge other claims that the giant pterosaurs - such as Pteranodon and the largest azhdarchids - were not capable of flying.
'Too heavy'
Researchers have previously suggested that these creatures were too heavy to have taken to the skies.
There have also been doubts that the ancient reptiles could have taken off using the same action as birds.
"Most birds take off either by running to pick up speed and jumping into the air before flapping wildly, or if they're small enough, they may simply launch themselves into the air from a standstill," said Dr Witton.
"Previous theories suggested that giant pterosaurs were too big and heavy to perform either of these manoeuvres."
He added: "These creatures were not birds; they were flying reptiles with a distinctly different skeletal structure, wing proportions and muscle mass.
"They would have achieved flight in a completely different way to birds and would have had a lower angle of take off and initial flight trajectory."
Muscle bulk
The authors of the latest study suggest that, with up to 50kg of forelimb muscle, the creatures could easily have launched themselves into the air despite their massive size and weight.
Dr Habib explained: "Instead of taking off with their legs alone, like birds, pterosaurs probably took off using all four of their limbs.
"By using their arms as the main engines for launching instead of their legs, they use the flight muscles - the strongest in their bodies - to take off and that gives them potential to launch much greater weight into the air," he explained.
"When they were far enough off the ground, they could start flapping their wings before finding a thermal or another area of uplift to gain some altitude and glide off to wherever they wanted to go," he told BBC News.
The largest pterosaurs may have had wingspans up to 13m and weighed up to 544kg.
But the authors' reappraisal of pterosaur fossils suggests these numbers may have been overestimated. They argue that the biggest creatures may have had 10-11m wingspans and weighed between 200 and 250 kg.
Pterosaur reptile used "pole vault" trick for take-off
Some have suggested the biggest pterosaurs were incapable of flight
A new study claims that the ancient winged reptiles known as pterosaurs used a "pole-vaulting" action to take to the air.
They say the creatures took off using all four of their limbs.
The reptiles vaulted over their wings, pushing off first with their hind limbs and then thrusting themselves upwards with their powerful arm muscles - not dissimilar to some modern bats.
The research is published in the open-access journal Plos One.
Pterosaurs lived at the same time as the dinosaurs, but belonged to a different group of reptiles. They existed from the Triassic Period until the end of the Cretaceous - about 220 million years ago to 65 million years ago.
In their study, Dr Mark Witton at Portsmouth University, UK, and Dr Michael Habib of Chatham University, Pennsylvania, US, reappraised giant pterosaur fossils.
Their findings challenge other claims that the giant pterosaurs - such as Pteranodon and the largest azhdarchids - were not capable of flying.
'Too heavy'
Researchers have previously suggested that these creatures were too heavy to have taken to the skies.
There have also been doubts that the ancient reptiles could have taken off using the same action as birds.
"Most birds take off either by running to pick up speed and jumping into the air before flapping wildly, or if they're small enough, they may simply launch themselves into the air from a standstill," said Dr Witton.
"Previous theories suggested that giant pterosaurs were too big and heavy to perform either of these manoeuvres."
He added: "These creatures were not birds; they were flying reptiles with a distinctly different skeletal structure, wing proportions and muscle mass.
"They would have achieved flight in a completely different way to birds and would have had a lower angle of take off and initial flight trajectory."
Muscle bulk
The authors of the latest study suggest that, with up to 50kg of forelimb muscle, the creatures could easily have launched themselves into the air despite their massive size and weight.
Dr Habib explained: "Instead of taking off with their legs alone, like birds, pterosaurs probably took off using all four of their limbs.
"By using their arms as the main engines for launching instead of their legs, they use the flight muscles - the strongest in their bodies - to take off and that gives them potential to launch much greater weight into the air," he explained.
"When they were far enough off the ground, they could start flapping their wings before finding a thermal or another area of uplift to gain some altitude and glide off to wherever they wanted to go," he told BBC News.
The largest pterosaurs may have had wingspans up to 13m and weighed up to 544kg.
But the authors' reappraisal of pterosaur fossils suggests these numbers may have been overestimated. They argue that the biggest creatures may have had 10-11m wingspans and weighed between 200 and 250 kg.
A new study claims that the ancient winged reptiles known as pterosaurs used a "pole-vaulting" action to take to the air.
They say the creatures took off using all four of their limbs.
The reptiles vaulted over their wings, pushing off first with their hind limbs and then thrusting themselves upwards with their powerful arm muscles - not dissimilar to some modern bats.
The research is published in the open-access journal Plos One.
Pterosaurs lived at the same time as the dinosaurs, but belonged to a different group of reptiles. They existed from the Triassic Period until the end of the Cretaceous - about 220 million years ago to 65 million years ago.
In their study, Dr Mark Witton at Portsmouth University, UK, and Dr Michael Habib of Chatham University, Pennsylvania, US, reappraised giant pterosaur fossils.
Their findings challenge other claims that the giant pterosaurs - such as Pteranodon and the largest azhdarchids - were not capable of flying.
'Too heavy'
Researchers have previously suggested that these creatures were too heavy to have taken to the skies.
There have also been doubts that the ancient reptiles could have taken off using the same action as birds.
"Most birds take off either by running to pick up speed and jumping into the air before flapping wildly, or if they're small enough, they may simply launch themselves into the air from a standstill," said Dr Witton.
"Previous theories suggested that giant pterosaurs were too big and heavy to perform either of these manoeuvres."
He added: "These creatures were not birds; they were flying reptiles with a distinctly different skeletal structure, wing proportions and muscle mass.
"They would have achieved flight in a completely different way to birds and would have had a lower angle of take off and initial flight trajectory."
Muscle bulk
The authors of the latest study suggest that, with up to 50kg of forelimb muscle, the creatures could easily have launched themselves into the air despite their massive size and weight.
Dr Habib explained: "Instead of taking off with their legs alone, like birds, pterosaurs probably took off using all four of their limbs.
"By using their arms as the main engines for launching instead of their legs, they use the flight muscles - the strongest in their bodies - to take off and that gives them potential to launch much greater weight into the air," he explained.
"When they were far enough off the ground, they could start flapping their wings before finding a thermal or another area of uplift to gain some altitude and glide off to wherever they wanted to go," he told BBC News.
The largest pterosaurs may have had wingspans up to 13m and weighed up to 544kg.
But the authors' reappraisal of pterosaur fossils suggests these numbers may have been overestimated. They argue that the biggest creatures may have had 10-11m wingspans and weighed between 200 and 250 kg.
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