Tag Archives: Jurassic

The People of the Wind

140-133 million years ago

John W. Campbell, the editor of Astounding Science Fiction magazine, used to challenge writers with new premises. One of his challenges was to imagine an alien that is to mammals as mammals are to reptiles. Science fiction writer Poul Anderson took up this challenge by inventing the Ythri, flying intelligent aliens of the planet Avalon, for his novel The People of the Wind. The Ythri were able to support the high metabolisms necessary for flight because they had a special system for supercharging their bloodstreams with extra oxygen.

Since Anderson’s time, we’ve learned that birds – and some dinosaurs – are actually somewhat Ythri-like. To begin with, consider non-dinosaur reptiles, like lizards: their sprawling posture means that their legs compress and expand their lungs as they run, so they can’t run and breathe at the same time. (David Carrier, a biologist at the University of Utah, was a main guy to figure this out.) If you had traveled back in time to the Paleozoic, before the dinosaurs took over, and if you had had good endurance training, you would have found the hunting easy, because the sprawling reptiles of the time would not have been able to run away for more than a short sprints. The predators to worry about would have been ambush hunters, not endurance hunters.

Dinosaurs got around these constraints in the first place by running bipedally (although some later reverted to quadrupedalism). And it now looks like at least some of them also had the sort of respiration we find in birds. Lungs are only part of birds’ respiratory systems. Birds also have an extensive network of air sacs running through their bodies, and even air passages in their bones. Air moves in both directions, in and out, like a bellows, through the air sacs, but only one direction through the lungs. This allows for more efficient circulation than mammalian lungs, where air has to move both in and out of the lungs. Just recently (2008), it’s been shown that Allosaurus, only distantly related to birds, had the same system, so it was probably widespread among dinosaurs. This breathing system may have helped dinosaurs to survive low-oxygen crises at the end of the Triassic, and flourish in the low oxygen Jurassic and Cretaceous. It may also have helped one group of dinosaurs to evolve into birds.

Anderson’s book isn’t just about respiratory physiology. It’s also about perennial issues of loyalty and identity. Avalon also has human settlers, who have so absorbed Ythri values — some of them even yearning, impossibly, to be Ythri — that they fight for an independent Avalon against an expanding Terran Empire. (Compare the movie Avatar.)

We’ll have more to say about bipedalism and breathing — and language — when human evolution comes up.

Amborella Day

207-196 million years ago

1 galactic revolution ago

The Triassic ends 201 million years ago with another major mass extinction (the fourth, by the usual count, after the end-Ordovician, end-Devonian, and end-Permian). Not quite as bad as the end-Permian (“only” 75% of species go extinct). This coincides with the formation of the Central Atlantic LIP (Large Igneous Province), which now includes a lot of eastern North America, northeast Amazonia, and western North Africa. So the end Triassic mass extinction may be the result of volcanoes spewing lava and carbon dioxide as Pangaea splits into Laurasia (North America, most of Eurasia) and Gondwanaland (South America, Africa, Antarctica, India, Australia).

The succeeding Jurassic Period will be when dinosaurs become the dominant vertebrates on land. The mammals around are mostly shrew-sized and nocturnal.

Not as conspicuous is another evolutionary innovation: the ancestors of Amborella, a rare shrub found in the wild only on New Caledonia, split off from the other angiosperms, ancestors of all other flowering plants, 200 million years ago. (This was suspected for a while, and confirmed in 2012 with the sequencing of the Amborella genome.) We can call this the origin of flowers. Amborella has clusters of small white flowers, with male and female separate.

amborella

Spring is gearing up in the Northern hemisphere; the honeybees have started to visit the earliest blooms on my apricot tree. If you’re lucky you’ll be able to smell the flowers on Amborella Day, and take your mind off catastrophes past and present.

The People of the Wind

146-139 million years ago

John W. Campbell, the editor of Astounding Science Fiction magazine, used to challenge writers with new premises. One of his challenges was to imagine an alien that is to mammals as mammals are to reptiles. Science fiction writer Poul Anderson took up this challenge by inventing the Ythri, flying intelligent aliens of the planet Avalon, for his novel The People of the Wind. The Ythri were able to support the high metabolisms necessary for flight because they had a special system for supercharging their bloodstreams with extra oxygen.

Since Anderson’s time, we’ve learned that birds – and some dinosaurs – are actually somewhat Ythri-like. To begin with, consider non-dinosaur reptiles, like lizards: their sprawling posture means that their legs compress and expand their lungs as they run, so they can’t run and breathe at the same time. (David Carrier, a biologist at the University of Utah, was a main guy to figure this out.) If you had traveled back in time to the Paleozoic, before the dinosaurs took over, and if you had good endurance training, you would have found the hunting easy, because the sprawling reptiles of the time would not have been able to run away for more than a short sprints. The predators to worry about would have been ambush hunters, not endurance hunters.

Dinosaurs got around these constraints in the first place by running bipedally (although some later reverted to quadrupedalism). And it now looks like at least some of them also had the sort of respiration we find in birds. Lungs are only part of birds’ respiratory systems. Birds also have an extensive network of air sacs running through their bodies, and even air passages in their bones. Air moves in both directions, in and out, like a bellows, through the air sacs, but only one direction through the lungs. This allows for more efficient circulation than mammalian lungs, where air has to move both in and out of the lungs. Just recently (2008), it’s been shown that Allosaurus, only distantly related to birds, had the same system, so it was probably widespread among dinosaurs. This breathing system may have helped dinosaurs to survive low-oxygen crises at the end of the Triassic, and flourish in the low oxygen Jurassic and Cretaceous. It may also have helped one group of dinosaurs to evolve into birds.

Anderson’s book isn’t just about respiratory physiology. It’s also about perennial issues of loyalty and identity. Avalon also has human settlers, who have so absorbed Ythri values — some of them even yearning, impossibly, to be Ythri — that they fight for an independent Avalon against an expanding Terran Empire. (Compare the movie Avatar.)

We’ll have more to say about bipedalism and breathing — and language — when human evolution comes up.

Amborella Day

205-194 million years ago

1 galactic revolution ago

The Triassic ends 201 million years ago with another major mass extinction (the fourth, by the usual count, after the end-Ordovician, end-Devonian, and end-Permian). Not quite as bad as the end-Permian (“only” 75% of species go extinct). This coincides with the formation of the Central Atlantic LIP (Large Igneous Province), which now includes a lot of eastern North America, northeast Amazonia, and western North Africa. So the end Triassic mass extinction may be the result of volcanoes spewing lava and carbon dioxide as Pangaea splits into Laurasia (North America, most of Eurasia) and Gondwanaland (South America, Africa, Antarctica, India, Australia).

The succeeding Jurassic Period will be when dinosaurs become the dominant vertebrates on land. The mammals around are mostly shrew-sized and nocturnal.

Not as conspicuous is another evolutionary innovation: the ancestors of Amborella, a rare shrub found in the wild only on New Caledonia, split off from the other angiosperms, ancestors of all other flowering plants, 200 million years ago. (This was suspected for a while, and confirmed in 2012 with the sequencing of the Amborella genome.) We can call this the origin of flowers. Amborella has clusters of small white flowers, with male and female separate.

amborella

People expect to get flowers on Mother’s Day and Valentine’s Day, but not on March 17. But Spring is gearing up in the Northern hemisphere. So surprise someone with flowers for Amborella Day!

The People of the Wind

146-139 million years ago

John W. Campbell, the editor of Astounding Science Fiction magazine, used to challenge writers with new premises. One of his challenges was to imagine an alien that is to mammals as mammals are to reptiles. Science fiction writer Poul Anderson took up this challenge by inventing the Ythri, flying intelligent aliens of the planet Avalon, for his novel The People of the Wind. The Ythri were able to support the high metabolisms necessary for flight because they had a special system for supercharging their bloodstreams with extra oxygen.

Since Anderson’s time, we’ve learned that birds – and some dinosaurs – are actually somewhat Ythri-like. To begin with, consider non-dinosaur reptiles, like lizards: their sprawling posture means that their legs compress and expand their lungs as they run, so they can’t run and breathe at the same time. (David Carrier, a biologist at the University of Utah, was a main guy to figure this out.) If you had traveled back in time to the Paleozoic, before the dinosaurs took over, and if you had good endurance training, you would have found the hunting easy, because the sprawling reptiles of the time would not have been able to run away for more than a short sprints. The predators to worry about would have been ambush hunters, not endurance hunters.

Dinosaurs got around these constraints in the first place by running bipedally (although some later reverted to quadrupedalism). And it now looks like at least some of them also had the sort of respiration we find in birds. Lungs are only part of birds’ respiratory systems. Birds also have an extensive network of air sacs running through their bodies, and even air passages in their bones. Air moves in both directions, in and out, like a bellows, through the air sacs, but only one direction through the lungs. This allows for more efficient circulation than mammalian lungs, where air has to move both in and out of the lungs. Just recently (2008), it’s been shown that Allosaurus, only distantly related to birds, had the same system, so it was probably widespread among dinosaurs. This breathing system may have helped dinosaurs to survive low-oxygen crises at the end of the Triassic, and flourish in the low oxygen Jurassic and Cretaceous. It may also have helped one group of dinosaurs to evolve into birds.

Anderson’s book isn’t just about respiratory physiology. It’s also about perennial issues of loyalty and identity. Avalon also has human settlers, who have so absorbed Ythri values — some of them even yearning, impossibly, to be Ythri — that they fight for an independent Avalon against an expanding Terran Empire. (Compare the movie Avatar.)

We’ll have more to say about bipedalism and breathing — and language — when human evolution comes up.

Amborella Day

205-194 million years ago

1 galactic revolution ago

The Triassic ends 201 million years ago with another major mass extinction (the fourth, by the usual count, after the end-Ordovician, end-Devonian, and end-Permian). Not quite as bad as the end-Permian (“only” 75% of species go extinct). This coincides with the formation of the Central Atlantic LIP (Large Igneous Province), which now includes a lot of eastern North America, northeast Amazonia, and western North Africa. So the end Triassic mass extinction may be the result of volcanoes spewing lava and carbon dioxide as Pangaea splits into Laurasia (North America, most of Eurasia) and Gondwanaland (South America, Africa, Antarctica, India, Australia).

The succeeding Jurassic Period will be when dinosaurs become the dominant vertebrates on land. The mammals around are mostly shrew-sized and nocturnal.

Not as conspicuous is another evolutionary innovation: the ancestors of Amborella, a rare shrub found in the wild only on New Caledonia, split off from the other angiosperms, ancestors of all other flowering plants, 200 million years ago. (This was suspected for a while, and confirmed in 2012 with the sequencing of the Amborella genome.) We can call this the origin of flowers. Amborella has clusters of small white flowers, with male and female separate.

amborella

People expect to get flowers on Mother’s Day and Valentine’s Day, but not on March 17. But Spring is gearing up in the Northern hemisphere. So surprise someone with flowers for Amborella Day!

The People of the Wind

163-154 million years ago

John W. Campbell, the editor of Astounding Science Fiction magazine, used to challenge writers with new premises. One of his challenges was to imagine an alien that is to mammals as mammals are to reptiles. Science fiction writer Poul Anderson took up this challenge by inventing the Ythri, flying intelligent aliens of the planet Avalon, for his novel The People of the Wind. The Ythri were able to support the high metabolisms necessary for flight because they had a special system for supercharging their bloodstreams with extra oxygen.

Since Anderson’s time, we’ve learned that birds – and some dinosaurs – are actually somewhat Ythri-like. To begin with, consider non-dinosaur reptiles, like lizards: their sprawling posture means that their legs compress and expand their lungs as they run, so they can’t run and breathe at the same time. (David Carrier, a biologist at the University of Utah, was a main guy to figure this out.) If you had traveled back in time to the Paleozoic, before the dinosaurs took over, and if you had good endurance training, you would have found the hunting easy, because the sprawling reptiles of the time would not have been able to run away for more than a short sprints. The predators to worry about would have been ambush hunters, not endurance hunters.

Dinosaurs got around these constraints in the first place by running bipedally (although some later reverted to quadrupedalism). And it now looks like at least some of them also had the sort of respiration we find in birds. Lungs are only part of birds’ respiratory systems. Birds also have an extensive network of air sacs running through their bodies, and even air passages in their bones. Air moves in both directions, in and out, like a bellows, through the air sacs, but only one direction through the lungs. This allows for more efficient circulation than mammalian lungs, where air has to move both in and out of the lungs. Just recently (2008), it’s been shown that Allosaurus, only distantly related to birds, had the same system, so it was probably widespread among dinosaurs. This breathing system may have helped dinosaurs to survive low-oxygen crises at the end of the Triassic, and flourish in the low oxygen Jurassic and Cretaceous. It may also have helped one group of dinosaurs to evolve into birds.

Anderson’s book isn’t just about respiratory physiology. It’s also about perennial issues of loyalty and identity. Avalon also has human settlers, who have so absorbed Ythri values — some of them even yearning, impossibly, to be Ythri — that they fight for an independent Avalon against an expanding Terran Empire. (Compare the movie Avatar.)

We’ll have more to say about bipedalism and breathing — and language — when human evolution comes up.