Another theory that all these scientists have pushed on us as a "fact" for so many years goes down. Remember people, these scientists do not have 100% proof to back up any of their claims.
NEW YORK - The big dinosaur extinction of 65 million years ago didn't produce a flurry of new species in the ancestry of modern mammals after all, says a huge study that challenges a long-standing theory.
Scientists who constructed a massive evolutionary family tree for mammals found no sign of such a burst of new species at that time among the ancestors of present-day animals.
Only mammals with no modern-day descendants showed that effect.
"I was flabbergasted," said study co-author Ross MacPhee, curator of vertebrate zoology at the American Museum of Natural History in New York.
At the time of the dinosaur demise, mammals were small, ranging in size between shrews and cats. The long-held view has been that once the dinosaurs were gone, mammals were suddenly free to exploit new food sources and habitats, and as a result they produced a burst of new species.
The new study says that happened to some extent, but that the new species led to evolutionary dead ends. In contrast, no such burst was found for the ancestors of modern-day mammals like rodents, cats, horses, elephants and people.
Instead, they showed an initial burst between 100 million about 85 million years ago, with another between about 55 million and 35 million year ago, researchers report in Thursday's issue of the journal Nature.
The timing of that first period of evolutionary development generally agrees with the conclusions of some previous studies of mammal DNA, which argue for a much earlier origin of some mammal lineages than the fossil record does.
The second burst had shown up in the fossil record, MacPhee said. But he said the new study explains why scientists have been unable to find relatively modern-looking ancestors of the creatures known from that time: without any evolutionary boost from the dinosaur demise, those ancestors were still relatively primitive.
Some experts praised the large scale of the new evolutionary tree, which used a controversial "supertree" method to combine data covering the vast majority of mammal species. It challenges paleontologists to find new fossils that can shed light on mammal history, said Greg Wilson, curator of vertebrate paleontology at the Denver Museum of Nature & Science.
William J. Murphy of Texas A&M University, who is working on a similar project, said no previous analysis had included so many mammal species.
But, "I don't think this is the final word," he said.
The study's approach for assigning dates was relatively crude, he said, and some dates it produced for particular lineages disagree with those obtained by more updated methods.
So as for its interpretation of what happened when the dinosaurs died off, "I'm not sure that conclusion is well-founded," Murphy said.
John Gittleman, a study co-author and director of the University of Georgia Institute of Ecology, said the researchers considered a range of previously reported dates for when various lineages split. They found the overall conclusions of the study were not significantly affected by which dates they chose, he said.
Researchers should now look at such things as the rise of flowering plants and a cooling of the worldwide climate to explain why ancestors of present-day mammals took off before the dinosaurs died out, Gittleman said. The cause of the later boom is also a mystery, he said.
The study's family tree includes 4,510 species, more than 99 percent of mammal species covered by an authoritative listing published in 1993. (Nearly 300 species have since been added to the listing, but the researchers said that doesn't affect their study's conclusions.) To construct it, the researchers combined previously published work that relied on analysis of DNA, fossils, anatomy and other information.
S. Blair Hedges, an evolutionary biologist at Pennsylvania State University, said the new work "pushes the envelope in the methods and data, and that's really important."
He said the demise of the dinosaurs may have affected mammal evolution by influencing characteristics like body size rather than boosting the number of new species created. Such changes wouldn't be picked up by the new study, he noted.
Is this another "Proof" that evolution never happened? Or is it just pointing out the fact, which I thought everyone knew, the scientists don't have have everything 100% accurate? Or just more interesting information?
I personally find evolution very interesting.
Another theory that all these scientists have pushed on us as a "fact" for so many years goes down. Remember people, these scientists do not have 100% proof to back up any of their claims.
Nobody has 'pushed' anything as 'fact'. Neither has anybody ever claimed to have 100% 'proof' to back up anything... apart from the 'scientific miracles' in the Qur'an, anyway
A scientific theory is accepted so far as it best explains the empirical evidence. It is junked if/when a better one comes along. That is how science works. BTW, nothing has "gone down" yet, .. it's an interesting study that challenges the current prevailing view, but it needs rather more than that.
The point I assume of posting this, is that what we believe is 100% fact now, may change out to be completly wrong. ie - evolution, or the dating systems we have.
In what way? It seems to me to hit the nail on the head. I don't even thnk option three is necessary. You either understand how science works, or you don't. It doesn't mean you have to embrace science with open arms even if you do.
In what way? It seems to me to hit the nail on the head. I don't even thnk option three is necessary. You either understand how science works, or you don't. It doesn't mean you have to embrace science with open arms even if you do.
He generalizes people who oppose what "Mainstream" science dictates we should all consider fact. Evolution is just as much of a theory as creationsim is. Yet one is taught as a scientific fact, while the other is taight as a myth and people who believe it should be ridiculed. The generalization is at fault, because wilberhum does not understand that science does change and what we viewed as fact 100 years ago could be fiction now.
Opposing mainstream science in favor of religion are not "Those that do not understand what a Scientific Theory is, so they say it is all wrong because it changes." They are people that understand that science changes and therefore do not take it word for word and will always continue to challenge the beliefs of these scientists because they recongnize that 100 years ago these scientists were telling us completly different things.
He generalizes people who oppose what "Mainstream" science dictates we should all consider fact. Evolution is just as much of a theory as creationsim is. Yet one is taught as a scientific fact, while the other is taight as a myth and people who believe it should be ridiculed. The generalization is at fault, because wilberhum does not understand that science does change and what we viewed as fact 100 years ago could be fiction now.
Opposing mainstream science in favor of religion are not "Those that do not understand what a Scientific Theory is, so they say it is all wrong because it changes." They are people that understand that science changes and therefore do not take it word for word and will always continue to challenge the beliefs of these scientists because they recongnize that 100 years ago these scientists were telling us completly different things.
You are clearly my number 2. Including the pun.
Evolution is just as much of a theory as creationsim is.
"Mainstream" science dictates we should all consider fact.
Where did you get that garbage. We are talking theory not fact. Do you not understand the difference?
Evolution is just as much of a theory as creationsim is.
Wrong evolution is a scientific theory. Creationism is mythical stories.
one is taught as a scientific fact,
Evolution is a theory, backed up my millions of facts. But it is apparent you do not understand the difference between theory and fact.
because wilberhum does not understand
It is obvious that you do not understand what I understand. You have proven your inability to understand.
If you want a really good theory, try FSM. It is better than creationism and a lot more fun.
Where did you get that garbage. We are talking theory not fact. Do you not understand the difference?
Wrong evolution is a scientific theory. Creationism is mythical stories.
Evolution is a theory, backed up my millions of facts. But it is apparent you do not understand the difference between theory and fact.
It is obvious that you do not understand what I understand. You have proven your inability to understand.
If you want a really good theory, try FSM. It is better than creationism and a lot more fun.
There are always going to be holes in a scientific theory dealing with events that occurred millions of years ago. About the only thing science is certain of is that large reptilian creatures walked the planet a long, long time ago. It would be hard to create a fossil record that explained the entire evolutionary process. Maybe I'm in the minority as a believing Christian, but the theory of evolution doesn't disturb me at all.
"Imagination was given to man to compensate him for what he is not, and a sense of humor was provided to console him for what he is."
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