 |
|
Dinosaur extinction didn't cause the rise of present-day mammals, claim researchers
March 29, 2007A new, complete 'tree of life' tracing the history of all 4,500 mammals on Earth shows that they did not diversify as a result of the death of the dinosaurs, says new research published in Nature today.
The study was undertaken in the UK by scientists at Imperial College London and the Zoological Society of London (ZSL). It contradicts the previously accepted theory that the Mass Extinction Event (MEE) that wiped out the dinosaurs 65 million years ago prompted the rapid rise of the mammals we see on the earth today.
The multinational research team has been working for over a decade to compile the tree of life from existing fossil records and new molecular analyses. They show that many of the genetic 'ancestors' of the mammals we see around us today existed 85 million years ago, and survived the meteor impact that is thought to have killed the dinosaurs. However, throughout the Cretaceous epoch, when dinosaurs walked the earth, these mammal species were relatively few in number, and were prevented from diversifying and evolving in ecosystems dominated by dinosaurs.
The tree of life shows that after the MEE, certain mammals did experience a rapid period of diversification and evolution. However, most of these groups have since either died out completely, such as Andrewsarchus (an aggressive wolf-like cow), or declined in diversity, such as the group containing sloths and armadillos.
The researchers believe that our 'ancestors', and those of all other mammals on earth now, began to radiate around the time of a sudden increase in the temperature of the planet - ten million years after the death of the dinosaurs.
Professor Andy Purvis from Imperial College London's Division of Biology explains: "Our research has shown that for the first 10 or 15 million years after the dinosaurs were wiped out, present day mammals kept a very low profile, while these other types of mammals were running the show. It looks like a later bout of 'global warming' may have kick-started today's diversity - not the death of the dinosaurs.
"This discovery rewrites our understanding of how we came to evolve on this planet, and the study as a whole gives a much clearer picture than ever before as to our place in nature."
Dr Kate Jones from the Zoological Society of London adds: "Not only does this research show that the extinction of the dinosaurs did not cause the evolution of modern-day mammals, it also provides us with a wealth of other information. Vitally, scientists will be able to use the research to look into the future and identify species that will be at risk of extinction. The benefit to global conservation will be incalculable.\\\
Imperial College London
The tree of life shows that after the MEE, certain mammals did experience a rapid period of diversification and evolution. However, most of these groups have since either died out completely, such as Andrewsarchus (an aggressive wolf-like cow), or declined in diversity, such as the group containing sloths and armadillos.
The researchers believe that our 'ancestors', and those of all other mammals on earth now, began to radiate around the time of a sudden increase in the temperature of the planet - ten million years after the death of the dinosaurs.
Professor Andy Purvis from Imperial College London's Division of Biology explains: "Our research has shown that for the first 10 or 15 million years after the dinosaurs were wiped out, present day mammals kept a very low profile, while these other types of mammals were running the show. It looks like a later bout of 'global warming' may have kick-started today's diversity - not the death of the dinosaurs.
"This discovery rewrites our understanding of how we came to evolve on this planet, and the study as a whole gives a much clearer picture than ever before as to our place in nature."
Dr Kate Jones from the Zoological Society of London adds: "Not only does this research show that the extinction of the dinosaurs did not cause the evolution of modern-day mammals, it also provides us with a wealth of other information. Vitally, scientists will be able to use the research to look into the future and identify species that will be at risk of extinction. The benefit to global conservation will be incalculable.\\\
Imperial College London
Dinosaur News and Current Dinosaur Events RSSAncient mother spawns new insight on reptile reproduction
A 75-million-year-old fossil of a pregnant turtle and a nest of fossilized eggs that were discovered in the badlands of southeastern Alberta by scientists and staff from the University of Calgary and the Royal Tyrrell Museum of Palaeontology are yielding new ideas on the evolution of egg-laying and reproduction in turtles and tortoises.
Duck-billed dinosaurs outgrew predators to survive
With long limbs and a soft body, the duck-billed hadrosaur had few defenses against predators such as tyrannosaurs. But new research on the bones of this plant-eating dinosaur suggests that it had at least one advantage: It grew to adulthood much faster than its predators, giving it superiority in size.
Feeding and fueling the future: the bioenergy potential of reviving abandoned agricultural land
Across the globe, hundreds of millions of acres of once-productive agricultural land lie abandoned, according to a new report from researchers at Stanford University and the Carnegie Institution for Science. If this land was used to grow crops for conversion into biofuel, it could help ease the energy crunch without worsening the world food shortage or contributing to global warming.
Mysterious mountain dino may be a new species
A partial dinosaur skeleton unearthed in 1971 from a remote British Columbia site is the first ever found in Canadian mountains and may represent a new species, according to a recent examination by a University of Alberta researcher.
Engineering researcher seeks answers to asteroid deflection
An Asteroid Deflection Research Center (ADRC) has been established on the Iowa State campus to bring researchers from around the world to develop asteroid deflection technologies. The center was signed into effect in April by the Office of the Executive Vice President and Provost.
Refining the date of the K/T boundary and the dinosaur extinction
Scientists at the University of California, Berkeley, and the Berkeley Geochronology Center have pinpointed the date of the dinosaurs' extinction more precisely than ever thanks to refinements to a common technique for dating rocks and fossils.
For the paper trail of life on Mars or other planets, find cellulose
Looking for evidence of life on Mars or other planets? Finding cellulose microfibers would be the next best thing to a close encounter, according to new research from the University of North Carolina at Chapel Hill.
Tuatara, the fastest evolving animal
In a study of New Zealand's "living dinosaur" the tuatara, evolutionary biologist, and ancient DNA expert, Professor David Lambert and his team from the Allan Wilson Centre for Molecular Ecology and Evolution recovered DNA sequences from the bones of ancient tuatara, which are up to 8000 years old.
New dinosaur from Mexico offers insights into ancient life on West America
A new species of dinosaur unearthed in Mexico is giving scientists fresh insights into the ancient history of western North America, according to an international research team led by scientists from the Utah Museum of Natural History at the University of Utah.
Bonn scientists simulate dinosaur digestion in the lab
Scientists from the University of Bonn are researching which plants giant dinosaurs could have lived off more than 100 million years ago.
More Dinosaur News Articles
 | Magic Tree House Boxed Set, Books 1-4: Dinosaurs Before Dark, The Knight at Dawn, Mummies in the Morning, and Pirates Past Noon by Mary Pope Osborne Get ready for a world of adventure with the first four titles in the beloved Magic Tree House series!Jack and his little sister Annie are just two regular kids from Frog Creek, Pennsylvania. Then they discover a mysterious tree house packed with all sorts of books...and their lives are never the same! Soon they are traveling through time and space in the magic tree house and having amazing... |
 | How Do Dinosaurs Play With Their Friends (How Do Dinosaurs) by Jane Yolen What if a dinosaur's friends come to play? Does he mope, does he pout if he can't get his way? Does he hide all his dump trucks, refusing to share? Does he throw his friends' coloring books up in the air? Time and time again, children are told to "play nice." This brilliantly illustrated board book is packed with rhymes that will teach children how. Mark Teague's laugh-aloud illustrations,... |
 | How to Be a Friend: A Guide to Making Friends and Keeping Them (Dino Life Guides for Families) by Laurie Krasny Brown Written and illustrated by the creators of the popular Dino Life Guides for Families, this book uses precise language and humorous illustrations to offer specific ways to be a friend and specific ways not to be one.A special section on how to deal with bosses and bullies has valuable information for young children going forth in the world and encountering these situations for the first... |
 | How Do Dinosaurs Go To School? (How Do Dinosaurs...) by Jane Yolen Everyone's favorite dinosaurs are back--and this time they are going to school. More fun dinosaur antics await. These prehistoric pupils are in a class of their own! As in their previous books, Yolen and Teague capture children's rambunctious natures with playful read-aloud verse and wonderfully amusing... |
 | Jurassic Park by Michael Crichton Unless your species evolved sometime after 1993 when Jurassic Park hit theaters, you're no doubt familiar with this dinosaur-bites-man disaster tale set on an island theme park gone terribly wrong. But if Speilberg's amped-up CGI creation left you longing for more scientific background and ... well, character development, check out the original Michael Crichton novel. Although not his best book... |
 | How Do Dinosaurs Say Goodnight? by Jane Yolen Featuring ten sleepy dinosaurs, this adorable picture book from prize-winning writer Jane Yolen and best-selling illustrator Mark Teague celebrates the funny, endearing, naughty bedtime behavior of young children... and young... |
 | Big Box of Boynton: Barnyard Dance! Pajama Time! Oh My Oh My Oh Dinosaurs! by Sandra Boynton What a perfect gift. Perfect for baby showers. Irresistible for a newborn, or for a one-, two-, even a three-year-old’s birthday. Ideal as a set that grandparents, aunts and uncles, in-laws, and close personal friends of the baby (babies have close personal friends?) will find particularly perfect to give. Housed in a bold, happy slipcase are three bestselling Boynton on Board books:... |
 | Operating System Concepts (7th Edition) by Abraham Silberschatz, Peter Baer Galvin, Greg Gagne Another defining moment in the evolution of operating systems Small footprint operating systems, such as those driving the handheld devices that the baby dinosaurs are using on the cover, are just one of the cutting-edge applications you'll find in Silberschatz, Galvin, and Gagne's Operating System Concepts, Seventh Edition. By staying current, remaining relevant, and adapting to emerging... |
 | Dinosaurs Divorce by Marc Brown, Laurie Krasny Brown |
 | Encyclopedia Prehistorica Dinosaurs: The Definitive Pop-Up From renowned pop-up masters Robert Sabuda and Matthew Reinhart comes an awe-inspiring tribute to the world's most beloved extinct animals and their 180-million-year reign on our planet.Open this book and a massive T. REX springs out, flashing a startling jawful of jagged teeth. Turn the next spread and a ravishing raptor unfurls and appears to fly off the edge of the page. Inside the amazing... |
| © 2008 BrightSurf.com |