Monday, 22 May 2017
Mammals began there ascent prior to dino extinction say scientists.
Mammals began their takeover long before the death of the dinosaurs
Source:
University of Southampton
New research reports that, contrary to popular belief, mammals began their massive diversification 10 to 20 million years before the extinction of the dinosaurs.
The study, involving Elis Newham from the University of Southampton, questioned the familiar story that dinosaurs dominated their prehistoric environment, while tiny mammals took a backseat, until the dinosaurs (besides birds) went extinct 66 million years ago, allowing mammals to shine.
Elis Newham, PhD student in Engineering and the Environment and co-author of the study, which is published Proceedings of the Royal Society B, said: "The traditional view is that mammals were suppressed during the 'age of the dinosaurs' and underwent a rapid diversification immediately following the extinction of the dinosaurs. However, our findings were that therian mammals, the ancestors of most modern mammals, were already diversifying considerably before the extinction event and the event also had a considerably negative impact on mammal diversity."
The old hypothesis hinged upon the fact that many of the early mammal fossils that had been found were from small, insect-eating animals -- there didn't seem to be much in the way of diversity. However, over the years, more and more early mammals have been found, including some hoofed animal predecessors the size of dogs. The animals' teeth were varied too.
The researchers analysed the molars of hundreds of early mammal specimens in museum fossil collections. They found that the mammals that lived during the years leading up to the dinosaurs' demise had widely varied tooth shapes, meaning that they had widely varied diets. These different diets proved key to an unexpected finding regarding mammal species going extinct along with the dinosaurs.
Not only did mammals begin diversifying earlier than previously expected, but the mass extinction wasn't the perfect opportunity for mammal evolution that it's traditionally been painted as. Early mammals were hit by a selective extinction at the same time the dinosaurs died out -- generalists that could live off of a wide variety of foods seemed more apt to survive, but many mammals with specialised diets went extinct.
The scientists involved with the study were surprised to see that mammals were initially negatively impacted by the mass extinction event. "I fully expected to see more diverse mammals immediately after the extinction," said lead author David Grossnickle, a Field Museum Fellow and PhD candidate at the University of Chicago. "I wasn't expecting to see any sort of drop. It didn't match the traditional view that after the extinction, mammals hit the ground running. It's part of the reason why I went back to study it further -- it seemed wrong."
The reason behind the mammals' pre-extinction diversification remains a mystery. Grossnickle suggests a possible link between the rise of mammals and the rise of flowering plants, which diversified around the same time. "We can't know for sure, but flowering plants might have offered new seeds and fruits for the mammals. And, if the plants co-evolved with new insects to pollinate them, the insects could have also been a food source for early mammals," he said.
Grossnickle notes that the study is particularly relevant in light of the mass extinction the earth is currently undergoing. He said: "The types of survivors that made it across the mass extinction 66 million years ago, mostly generalists, might be indicative of what will survive in the next hundred years, the next thousand."
Story Source:
The above post is reprinted from materials provided by University of Southampton. Note: Materials may be edited for content and length.
Source:
University of Southampton
New research reports that, contrary to popular belief, mammals began their massive diversification 10 to 20 million years before the extinction of the dinosaurs.
The study, involving Elis Newham from the University of Southampton, questioned the familiar story that dinosaurs dominated their prehistoric environment, while tiny mammals took a backseat, until the dinosaurs (besides birds) went extinct 66 million years ago, allowing mammals to shine.
Elis Newham, PhD student in Engineering and the Environment and co-author of the study, which is published Proceedings of the Royal Society B, said: "The traditional view is that mammals were suppressed during the 'age of the dinosaurs' and underwent a rapid diversification immediately following the extinction of the dinosaurs. However, our findings were that therian mammals, the ancestors of most modern mammals, were already diversifying considerably before the extinction event and the event also had a considerably negative impact on mammal diversity."
The old hypothesis hinged upon the fact that many of the early mammal fossils that had been found were from small, insect-eating animals -- there didn't seem to be much in the way of diversity. However, over the years, more and more early mammals have been found, including some hoofed animal predecessors the size of dogs. The animals' teeth were varied too.
The researchers analysed the molars of hundreds of early mammal specimens in museum fossil collections. They found that the mammals that lived during the years leading up to the dinosaurs' demise had widely varied tooth shapes, meaning that they had widely varied diets. These different diets proved key to an unexpected finding regarding mammal species going extinct along with the dinosaurs.
Not only did mammals begin diversifying earlier than previously expected, but the mass extinction wasn't the perfect opportunity for mammal evolution that it's traditionally been painted as. Early mammals were hit by a selective extinction at the same time the dinosaurs died out -- generalists that could live off of a wide variety of foods seemed more apt to survive, but many mammals with specialised diets went extinct.
The scientists involved with the study were surprised to see that mammals were initially negatively impacted by the mass extinction event. "I fully expected to see more diverse mammals immediately after the extinction," said lead author David Grossnickle, a Field Museum Fellow and PhD candidate at the University of Chicago. "I wasn't expecting to see any sort of drop. It didn't match the traditional view that after the extinction, mammals hit the ground running. It's part of the reason why I went back to study it further -- it seemed wrong."
The reason behind the mammals' pre-extinction diversification remains a mystery. Grossnickle suggests a possible link between the rise of mammals and the rise of flowering plants, which diversified around the same time. "We can't know for sure, but flowering plants might have offered new seeds and fruits for the mammals. And, if the plants co-evolved with new insects to pollinate them, the insects could have also been a food source for early mammals," he said.
Grossnickle notes that the study is particularly relevant in light of the mass extinction the earth is currently undergoing. He said: "The types of survivors that made it across the mass extinction 66 million years ago, mostly generalists, might be indicative of what will survive in the next hundred years, the next thousand."
Story Source:
The above post is reprinted from materials provided by University of Southampton. Note: Materials may be edited for content and length.
Why multiverse speculation leaves some cold.
A Cold Spot In Space — “Evidence” of a Multiverse?
David Klinghoffer | @d_klinghoffer
Cosmic fine tuning, with physics and chemistry conspiring to permit the existence of creatures such as ourselves, is one of best-recognized pieces of evidence for intelligent design. To this, the hypothesis of a multiverse is materialism’s only response.
According to this line of reasoning, or imagining, our universe reflects only a lucky roll of the dice. A very, very, very lucky roll, which, however, is just to be expected if reality sports not one but a possibly infinite number of universes. Some universe was bound to get lucky, and it was ours.
It’s the single dreamiest, most unsupported idea in all of science, making Darwinian evolution look like a really solid bet by comparison. What’s wanted is real evidence for the multiverse, any at all, and that seems doomed to go on lacking ad infinitum.
Trumped up evidence is nevertheless a regular feature of popular science journalism. The latest: a headline in The Guardian, “Multiverse: have astronomers found evidence of parallel universes?” Adding the question mark is prudent, since the answer, to be truthful, is No.
Author Stuart Clark got hold of a press release from the Royal Astronomical Society, which he wheels out after an introduction heavy with jokey references to Brexit, Trump, the alt-right, and cat videos.
It sounds bonkers but the latest piece of evidence that could favour a multiverse comes from the UK’s Royal Astronomical Society. They recently published a study on the so-called ‘cold spot’. This is a particularly cool patch of space seen in the radiation produced by the formation of the Universe more than 13 billion years ago.
The cold spot was first glimpsed by NASA’s WMAP satellite in 2004, and then confirmed by ESA’s Planck mission in 2013. It is supremely puzzling. Most astronomers and cosmologists believe that it is highly unlikely to have been produced by the birth of the universe as it is mathematically difficult for the leading theory — which is called inflation — to explain.
This latest study claims to rule out a last-ditch prosaic explanation: that the cold spot is an optical illusion produced by a lack of intervening galaxies.
One of the study’s authors, Professor Tom Shanks of Durham University, told the RAS, “We can’t entirely rule out that the Spot is caused by an unlikely fluctuation explained by the standard [theory of the Big Bang]. But if that isn’t the answer, then there are more exotic explanations. Perhaps the most exciting of these is that the Cold Spot was caused by a collision between our universe and another bubble universe. If further, more detailed, analysis … proves this to be the case then the Cold Spot might be taken as the first evidence for the multiverse.” [Emphasis added.]
Count the instances of speculative language in those last four sentences. “Can’t entirely rule out…If that isn’t the answers…Perhaps…If further, more detailed, analysis…proves…[M]ight be taken as the first evidence…”
It’s “Heady stuff,” Clark exclaims. That’s one way of putting it. The paper in question, though, says just this (“Evidence against a supervoid causing the CMB Cold Spot”):
If not explained by a ΛCDM ISW effect the Cold Spot could have more exotic primordial origins. If it is a non-Gaussian feature, then explanations would then include either the presence in the early universe of topological defects such as textures (Cruz et al. 2007) or inhomogeneous re-heating associated with non-standard inflation (Bueno Sa ́nchez 2014). Another explanation could be that the Cold Spot is the remnant of a collision between our Universe and another ‘bubble’ universe during an early inflationary phase (Chang et al. 2009, Larjo & Levi 2010). It must be borne in mind that even without a supervoid the Cold Spot may still be caused by an unlikely statistical fluctuation in the standard (Gaussian) ΛCDM cosmology.
In this way, based ultimately on a couple of parenthetically referenced papers from 2009 and 2010, a “cold spot” in space answers one of the ultimate questions that have ever puzzled human beings, tipping the scales toward a universe, or multiverse, without design or purpose. As of the present moment, in the quest to explain away ultra-fine tuning, this is the best kind of stuff that materialism has got to offer.
It’s all the most absurd axe-grinding: building your case against a person or idea you don’t like (intelligent design, in this case) by gathering rumors, dreams, and guesses, disregarding common sense and objective evidence, since the conclusion you wish to reach, that you are bound to reach, is already pre-set.
So materialism goes on its merry way, largely unchallenged, with the media as its bullhorn. If scientists advocating the theory of intelligent design ever went before the public with conjectures as weak as this, they would be flayed alive.
David Klinghoffer | @d_klinghoffer
Cosmic fine tuning, with physics and chemistry conspiring to permit the existence of creatures such as ourselves, is one of best-recognized pieces of evidence for intelligent design. To this, the hypothesis of a multiverse is materialism’s only response.
According to this line of reasoning, or imagining, our universe reflects only a lucky roll of the dice. A very, very, very lucky roll, which, however, is just to be expected if reality sports not one but a possibly infinite number of universes. Some universe was bound to get lucky, and it was ours.
It’s the single dreamiest, most unsupported idea in all of science, making Darwinian evolution look like a really solid bet by comparison. What’s wanted is real evidence for the multiverse, any at all, and that seems doomed to go on lacking ad infinitum.
Trumped up evidence is nevertheless a regular feature of popular science journalism. The latest: a headline in The Guardian, “Multiverse: have astronomers found evidence of parallel universes?” Adding the question mark is prudent, since the answer, to be truthful, is No.
Author Stuart Clark got hold of a press release from the Royal Astronomical Society, which he wheels out after an introduction heavy with jokey references to Brexit, Trump, the alt-right, and cat videos.
It sounds bonkers but the latest piece of evidence that could favour a multiverse comes from the UK’s Royal Astronomical Society. They recently published a study on the so-called ‘cold spot’. This is a particularly cool patch of space seen in the radiation produced by the formation of the Universe more than 13 billion years ago.
The cold spot was first glimpsed by NASA’s WMAP satellite in 2004, and then confirmed by ESA’s Planck mission in 2013. It is supremely puzzling. Most astronomers and cosmologists believe that it is highly unlikely to have been produced by the birth of the universe as it is mathematically difficult for the leading theory — which is called inflation — to explain.
This latest study claims to rule out a last-ditch prosaic explanation: that the cold spot is an optical illusion produced by a lack of intervening galaxies.
One of the study’s authors, Professor Tom Shanks of Durham University, told the RAS, “We can’t entirely rule out that the Spot is caused by an unlikely fluctuation explained by the standard [theory of the Big Bang]. But if that isn’t the answer, then there are more exotic explanations. Perhaps the most exciting of these is that the Cold Spot was caused by a collision between our universe and another bubble universe. If further, more detailed, analysis … proves this to be the case then the Cold Spot might be taken as the first evidence for the multiverse.” [Emphasis added.]
Count the instances of speculative language in those last four sentences. “Can’t entirely rule out…If that isn’t the answers…Perhaps…If further, more detailed, analysis…proves…[M]ight be taken as the first evidence…”
It’s “Heady stuff,” Clark exclaims. That’s one way of putting it. The paper in question, though, says just this (“Evidence against a supervoid causing the CMB Cold Spot”):
If not explained by a ΛCDM ISW effect the Cold Spot could have more exotic primordial origins. If it is a non-Gaussian feature, then explanations would then include either the presence in the early universe of topological defects such as textures (Cruz et al. 2007) or inhomogeneous re-heating associated with non-standard inflation (Bueno Sa ́nchez 2014). Another explanation could be that the Cold Spot is the remnant of a collision between our Universe and another ‘bubble’ universe during an early inflationary phase (Chang et al. 2009, Larjo & Levi 2010). It must be borne in mind that even without a supervoid the Cold Spot may still be caused by an unlikely statistical fluctuation in the standard (Gaussian) ΛCDM cosmology.
In this way, based ultimately on a couple of parenthetically referenced papers from 2009 and 2010, a “cold spot” in space answers one of the ultimate questions that have ever puzzled human beings, tipping the scales toward a universe, or multiverse, without design or purpose. As of the present moment, in the quest to explain away ultra-fine tuning, this is the best kind of stuff that materialism has got to offer.
It’s all the most absurd axe-grinding: building your case against a person or idea you don’t like (intelligent design, in this case) by gathering rumors, dreams, and guesses, disregarding common sense and objective evidence, since the conclusion you wish to reach, that you are bound to reach, is already pre-set.
So materialism goes on its merry way, largely unchallenged, with the media as its bullhorn. If scientists advocating the theory of intelligent design ever went before the public with conjectures as weak as this, they would be flayed alive.
New theory or old theory 2.0?
A “Nachos and Ice Cream” Theory of Evolution
David Klinghoffer | @d_klinghoffer
If the old theory of evolution was so great, why do they keep rolling out new ones? You notice, however, that the “new,” “extended,” “fundamentally revised” theories – with the exception of the theory of intelligent design – always turn out to be more or less repackaged versions of the same old, same old. Without recourse to mind, they fail again and again to solve the main problem.
Case in point: Sarah Zhang in The Atlantic heralds, “A Grand New Theory of Life’s Evolution on Earth.” At long last, is this the “theory of the generative” we’ve been waiting for?
No. The “new theory” from Olivia Judson of Imperial College London is a neat way of classifying sweeping time frames, “energetic epochs,” where life had energy sources made freshly available, thus making increasingly complex life possible.
The modern world gives us such ready access to nachos and ice cream that it’s easy to forget: Humans bodies require a ridiculous and — for most of Earth’s history — improbable amount of energy to stay alive.
Consider a human dropped into primordial soup 3.8 billion years ago, when life first began. They would have nothing to eat. Earth then had no plants, no animals, no oxygen even. Good luck scrounging up 1600 calories a day drinking pond- or sea water. So how did we get sources of concentrated energy (i.e. food) growing on trees and lumbering through grass? How did we end up with a planet that can support billions of energy-hungry, big-brained, warm-blooded, upright-walking humans?
In“The Energy Expansions of Evolution,” an extraordinary new essay in Nature Ecology and Evolution, Olivia Judson sets out a theory of successive energy revolutions that purports to explain how our planet came to have such a diversity of environments that support such a rich array of life, from the cyanobacteria to daisies to humans.
Judson divides the history of the life on Earth into five energetic epochs, a novel schema that you will not find in geology or biology textbooks. In order, the energetic epochs are: geochemical energy, sunlight, oxygen, flesh, and fire. Each epoch represents the unlocking of a new source of energy, coinciding with new organisms able to exploit that source and alter their planet. The previous sources of energy stay around, so environments and life on Earth become ever more diverse. Judson calls it a “step-wise construction of a life-planet system.” [Emphasis added.]
The key word in that passage may be “coincide.” Energy – delivered in the form of “nachos and ice cream,” or whatever the case might be — is necessary but not sufficient in explaining how complex life arises. Merely “coinciding” with great leaps forward in biological complexity doesn’t cut it. The really grand mystery remains the origin of biological information. See our short video, “The Information Enigma.” Positing “energetic epochs” does nothing to resolve that enigma.
She mentions oxygen. In the context of explaining the Cambrian explosion, a classic fallacy is the “oxygen theory,” holding that new body plans arose thanks newly available oxygen. As we’ve noted many times before, oxygen has no ability to compose coded information, generating the software on which life runs.
The point about fire is interesting, and should ring a bell. Zhang summarizes:
Then one particular type of animal — those of the genus Homo — figure out fire. Fire lets us cook, which may have allowed us to get more nutrition out of the same food. It lets us forge labor-saving metal tools. It lets us create fertilizer through the Haber-Bosch process to grow food on industrial scales. It lets us burn fossil fuels for energy.
True enough. But this brief treatment falls well short of Michael Denton’s research and writing on the same subject. Fire does more than harness fuel to provide energy. It reveals how nature has been specially fitted for a creature like man, and vice versa. See, “Fire-Maker: How Humans Were Designed to Harness Fire & Transform Our Planet.”
David Klinghoffer | @d_klinghoffer
If the old theory of evolution was so great, why do they keep rolling out new ones? You notice, however, that the “new,” “extended,” “fundamentally revised” theories – with the exception of the theory of intelligent design – always turn out to be more or less repackaged versions of the same old, same old. Without recourse to mind, they fail again and again to solve the main problem.
Case in point: Sarah Zhang in The Atlantic heralds, “A Grand New Theory of Life’s Evolution on Earth.” At long last, is this the “theory of the generative” we’ve been waiting for?
No. The “new theory” from Olivia Judson of Imperial College London is a neat way of classifying sweeping time frames, “energetic epochs,” where life had energy sources made freshly available, thus making increasingly complex life possible.
The modern world gives us such ready access to nachos and ice cream that it’s easy to forget: Humans bodies require a ridiculous and — for most of Earth’s history — improbable amount of energy to stay alive.
Consider a human dropped into primordial soup 3.8 billion years ago, when life first began. They would have nothing to eat. Earth then had no plants, no animals, no oxygen even. Good luck scrounging up 1600 calories a day drinking pond- or sea water. So how did we get sources of concentrated energy (i.e. food) growing on trees and lumbering through grass? How did we end up with a planet that can support billions of energy-hungry, big-brained, warm-blooded, upright-walking humans?
In“The Energy Expansions of Evolution,” an extraordinary new essay in Nature Ecology and Evolution, Olivia Judson sets out a theory of successive energy revolutions that purports to explain how our planet came to have such a diversity of environments that support such a rich array of life, from the cyanobacteria to daisies to humans.
Judson divides the history of the life on Earth into five energetic epochs, a novel schema that you will not find in geology or biology textbooks. In order, the energetic epochs are: geochemical energy, sunlight, oxygen, flesh, and fire. Each epoch represents the unlocking of a new source of energy, coinciding with new organisms able to exploit that source and alter their planet. The previous sources of energy stay around, so environments and life on Earth become ever more diverse. Judson calls it a “step-wise construction of a life-planet system.” [Emphasis added.]
The key word in that passage may be “coincide.” Energy – delivered in the form of “nachos and ice cream,” or whatever the case might be — is necessary but not sufficient in explaining how complex life arises. Merely “coinciding” with great leaps forward in biological complexity doesn’t cut it. The really grand mystery remains the origin of biological information. See our short video, “The Information Enigma.” Positing “energetic epochs” does nothing to resolve that enigma.
She mentions oxygen. In the context of explaining the Cambrian explosion, a classic fallacy is the “oxygen theory,” holding that new body plans arose thanks newly available oxygen. As we’ve noted many times before, oxygen has no ability to compose coded information, generating the software on which life runs.
The point about fire is interesting, and should ring a bell. Zhang summarizes:
Then one particular type of animal — those of the genus Homo — figure out fire. Fire lets us cook, which may have allowed us to get more nutrition out of the same food. It lets us forge labor-saving metal tools. It lets us create fertilizer through the Haber-Bosch process to grow food on industrial scales. It lets us burn fossil fuels for energy.
True enough. But this brief treatment falls well short of Michael Denton’s research and writing on the same subject. Fire does more than harness fuel to provide energy. It reveals how nature has been specially fitted for a creature like man, and vice versa. See, “Fire-Maker: How Humans Were Designed to Harness Fire & Transform Our Planet.”
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