Explain why Wegener's theory of continental drift was not accepted at first.?
356538
Two main reasons:\n\nFirst, he could not explain *how* continents were able to move.\n\nSecond, he suggested that the reate of drift was ten to a hundred times faster than we now know to be true.\n\nI would suggest that, third, the idea is so counterintuitive -- because human lives are so short, in geological terms, continents seem to us to be utterly constant and permanent.
283532
Man_with_a_Plan has no proof that there is no proof. His statement that no theories are sound or have proof is just his opinion and purely speculatory. There is no proof.\n\nI, on the other hand, like the "Murder on the Orient Express Theory". I think that there was huge changes in ocean circulation due to the continents coming together WELL BEFORE Pangaea formed. The geologic evidence suggests that the extinction happened in different places around the world at different times, which suggests that no single event is responsible. I believe that cooling events like plume volcanism in the Siberian traps coupled with warming events like methane hydrate release and greenhouse effect along with the continental positioning at the time may have worked together to cause extreme changes in ocean circulation at various parts of the world at different times, attributing to the extinction event.\n\nVariations in temperature due to greenhouse warming and on/off sulphide cooling would have had the greatest immediate impact on planktic (ocean surface) and shallow water organisms. I also think that ocean circulation was also greatly affected not only by the temperature variations but also the circumstantial orientation of the continents. Heat transport to the north would have been innefficient and consequently northern regions would have been subject to extreme cooling, even at relatively low latitudes. In the southern regions there would have been a huge temperature gradient between top and bottom waters. If this was enough to stop deep water formation and ocean turnover, benthic (bottom dwelling) species would have been destroyed by the lack of oxygen and intermediate to surface water species would have suffered from a lack of nutrients. Because most of the Earth's life at the time was in the water, I am quite sure that it was likely some change in ocean circulation that dealt the fatal blows to life. Obviously good carbon isotope data from the period would be needed to verify this hypothesis. \n\nLife on land would have suffered greatly by climate changes induced by changes in ocean circulation, as well as the extreme variations in temperature. Tropical species would have been devastated by cooling events caused by the plume volcanism.\n\nThere is lots of proof for everything; there just is no definite information that can, as of yet, say for sure exactly how it all happened. That's a tough thing to do, but I really dislike people who refute the claims of others without presenting any evidence themselves.
38918
Mandy and Benny both have valid points. It's because of plate tectonics, because of which continents moved. Pangea (single continent) that existed millions and millions of years ago...slowly started dispersing and if you see the movement of india subcontinent, it moved all the way from southern africa and joined asian continent. This must have created a pileup of land that benny is talking about.
98865
It was once thought that land on earth is stationary and that the continents had always been their current shape, even though they may have been covered by more water.\n\nMore recently however, it has been discovered that the continents were actually all one mass of land and at one point separated, floating apart on sheets of plate tectonics.  \n\nProof came quickly.  It is now easy to see the east coast of South America fitting into west Africa for instance.  Bones of related land-dwelling creatures were also found on the coastlines of the two distant continents.
113213
Ahem. People, he's asking about the RATE of change. Not whether changes occur or whether evolution occurs. He clearly already knows that.\n\n__________________________________\n\nWell done. You’ve asked one of the most controversial questions in current evolutionary biology.  Much debate rages about this subject right now. \n\nWhat you are describing is commonly referred to as the evolution of evolvability. As you point out, if a population doesn’t have sufficient variation then environmental change could lead to extinction. But at the same time if the population is too variable the outliers will simply perish in current conditions. For example if elephants contained the inherent variability to produce young twice as big or the size of a rabbit those individuals would die.\n\nThe belief was for 100 years or so that the selective pressure of current environment would maintain a fairly tight rein on variability, that mutation rates were approximately constant and that survival in times of change was simply a case of pot luck. But then people started to look at the fossil record and the real world and it seemed like that wasn’t plausible. Novelties seemed to appear almost overnight, and they appeared almost any time they were needed. \n\nSo then came the concept of punctuated equilibrium. The idea that  a population would sit still for long periods, then as conditions changed they would suddenly leap forwards into a radically different form. That was all well and good, but it was basically just a restatement of the observations, not really an explanatory theory.\n\nIn the past 15 years ago there has been a lot of debate about the idea that organisms have evolved to evolve. That they have evolved in such a way that they are physically stable in times of environmental stasis, but when the environment becomes stressful change they can either mutate more, or reshuffle genes or express pattern of dormant genes to produce stable phenotypic novelties at rates that far exceed background rates.\n\n\nThe theory certainly makes sense. It’s hard to argue that such a trait wouldn’t; be a survival advantage. Unfortunately the evidence is ambiguous. And at the moment there are umpteen dozen theoretical mechanisms to explain how it could occur, and they are impossible to separate out. There is some work which has shown that many species can open up dormant genetic material for expression and re-assortment in response to stress (see first link below). And some experimental evidence suggests mutation rates increase in response to environmental change. Some say that prions are the key. Other favour inherent genetic instability in those individuals that survive initial changes, meaning that the decedent population is inherently prone to genetic varaiation until the environment stabilises and kills of the outliers again. Other propose that assortment of populations within the same or closely related species could explain it. But at this point we can’t even prove that genetic variation does change under stress. But at this point we just don’t know. \n\nYou ask a damn good question but the concept is hard to study and harder to establish with any certainty.\n\n_______\n>>>>Being able to actually understand how, and under what\n>>>> circumstances mutations happen strikes me as extremely\n>>>> important.\n\nWe've actually got a pretty good handle on how and when mutations occur. This is more of a question of when they are expressed or encouraged. Organisms have the ability repair genetic damage thorugh several mechanisms. They also have the ability shield the nucleus fom many mutagens. The issue is whether they may be able to damp down those processes to encourage more mutations.\n\n>>>> I can definitely see that species that do not have the \n>>>>capability to mutate in response to external forces\n>>>> would be selected against.\n\nYes, it's a rather hard
1135377
You have to look at evolution as a series of slight beneficial changes that are passed down through generations.  The steps from single to double circ are unknown to me, but it is more than a single big jump.
237532
if the environment changes faster than the organisms ability to adapt to the changes, the species will go extinct. The reason, be it man made, or natural, is irrelevant. The point is, there is a change, and the organism cannot adapt.
1010692
ok first of all just because one thing the bible says is true,that wouldnt make the entire thing true and second of all,originally the Earth was a ball of molten rock that cooled down.water didnt come around till later(im not sure how though)
160973
No Definitely not. Man could never tame or alter the path of the plates. However I do believe he may have alredy implemented change on the Convection currents. Global warming was probably helped by man during the Industrial revolution and has gone on ever since. Dont just blame America. I have seen some appalling instances of Major pollution in India and several other third world countries. It is a global thing and all countries of the world are guilty of some form of pollution.
320406
There are many things that support the theory of evolution.  Mainly, the fossil record and the fact that you are here, though if natural selection holds true, you will not be working in any fied of science any time soon. \nThe tide example that you state does not disprove evolution because it's false; the amount of water in the world has not change as you suggest.  There is no reason to believe that any change in tides would work increasingly to cover the earth with water.  There are fluctuations in the level of the seas that follow geological and thermal events over the course of centuries and millenia, like the ice ages. In second place, evolution is not about the age of the earth, it's about natural adaptation to the environment. Examples to prove it can be found anywhere in nature.  Sea iguanas in Galapagos are one of the best-known examples of adaptive development.   If there was no evolution, these iguanas would be terrestrial like all of the other species of iguana in the world.  But they're not, they have evolved an adaptation to marine environments.  Think of that as a microcosm of what happens in the rest of nature.\nWhy do we have a residual tailbone?  Why do whales have residual fingers?  We don't have tails and we don't need them, but the tailbone is there...  If someone meant for us to have a tail, they would have given us a tail or none altogether.  The fact that we have a bone structure that serves no apparent purpose but to cause pain when you fall on your but and break it proves that there is an ongoing process that we are a part of.\nEvolution does not exclude creation, it just makes creation dynamic and alive at a much broader scale.  That creation cannot be a process driven by biology instead of a stagnant  pile of events is not written anywhere in any holy book.
1123593
There is some evidence that the fine structure constant has changed over time. However, the degree of change is less than 1/10 of a percent over 10 billion years. This is certainly not enough to justify a young universe model. It should be pointed out that the cDK people like to point to supposed decreases in measured values of c without looking at the error bars on those measurements. They also have a great tendency to pick and choose measurements rather than look at all the ones available. For example, Romer's original estimate of c was lower than the currently accepted one.\n\nUntlimatey, the goal of cDK is to make it possible for the universe to be only 10,000 years old ather than 13.7 billion. This is to bring things into line with biblical literalism. However, it was clear even before radioactive dating that the earth was at least millions of years old.\n\nSorry, ad hoc explanations without any justification.
663844
Jumping into the Evolution vs. Creationism is a messy fight.  What Baumgardner proposes is a very rapid movement of the plates to get them into the current position and also creating the massive flood referred to in the Christian Bible.  Geologic evidence refutes the theory at every turn.  The structure of the earth as we know it will not allow this.  The aesthenosphere is the plastic-y layer over which the solid plates move.  Geophysical and surface observed evidence tell us that this is a very slow process, inches a year at a maximum.  The type of catastrophic event describes in this theory would not be physically possible by the natural laws we have observerd.  Also, radio carbon dating shows the varying ages of rock throughout the Earth, ages that far exceed the several thousand years he posits.  His response is that the radio isotopes decayed at a diferent rate.  Basically, he wants the laws of science, the laws that have never been seen to change, to be broken to support his creationism theory.  I suppose if you believe in an omnipotent being that created the world, that being can change the laws as it sees fit; however, that isn't science, that is belief.\n\nMy opinion is that Baumgardner's theory is a feeble attemptto put a scientific face on religious thought.  The website I reference is a Evolution vs. creation discussion group.  Many people spent far more thought on the subject and you can find some very good points in the discussion thread.
393412
A Thousand years, or one trillion trillionth of a second time is of no consequence, I myself have concluded that time is a independent state of function, so with respect to your question I would say that possibly it does not take so many years for a mountain to form, and it is only with direct respect to our perceptions that it seems as such with respect to our measurement of the passage of time, although the function of mountain formation is with direct respect to plate tectonics's in which our planets surface which is also measured by our perceptions as extremely hard, and  dense actually moves on a river of swirling molten lava, and as two continents pull away from one another they are stretched and valleys, and crevasse's, are formed, although you cannot observe them because the oceans are covering there surface, although on the opposing end of the spectrum, and at the end in which two continents or surface plates come together, Continent plate "1" will force Continent plate "2" under Continent "1", then as Continent "2" travels under Continent "1", then at that point Mountains are formed as continent "1" Rises.\n\nTherefore with direct respect to your question, I hope that this helps you see possibly that the fact of time measurement with respect to mountain formation is of little consequence to the functional action which brings about there creation, as time measurement is merely associated by the perceptions of consciousness of the entity's measuring the observations with direct respect to there time plane.
109251
plate tectonics provides an explanation for the continental drift hypothesis.
238705
One. It was called pangaea heres some more info:\n\nPangaea or Pangea (derived from Παγγαία, Greek for "all earth") is the name given to the supercontinent that existed during the Paleozoic and Mesozoic eras, before the process of plate tectonics separated each of the component continents into their current configuration. The name was coined by Alfred Wegener, chief proponent of Continental Drift in 1915.\n\nThe continents apparently first coalesced to form Pangaea about 300 Mya (million years ago), giving rise to several prominent mountain ranges by the process known as orogeny. Several of these ranges still exist, although they have become much lower by means of erosion. The Appalachians of eastern North America, the Atlas Mountains of North Africa, and the Urals of Eurasia are prime examples. The mantle under Pangaea's former location seemingly remained very hot even after coalescence, convection currents within the underlying magma pushing the centre of the supercontinent upward. As a result, the area that is now the continent of Africa was situated tens of meters higher than the surrounding continents.\n\nIn configuration, Pangaea was a C-shaped landmass that spread across the equator. The body of water that was enclosed within the resulting crescent has been named the Tethys Sea. Owing to Pangaea's massive size, the inland regions appear to have been very dry due to the lack of precipitation. The large supercontinent would potentially have allowed terrestrial animals to migrate freely all the way from the South Pole to the North Pole.\n\nThe vast ocean that once surrounded the supercontinent of Pangaea has been named Panthalassa. Pangaea, it seems, broke up about 180 Ma in the Jurassic Period, firstly into two supercontinents (Gondwana to the south and Laurasia to the north), thereafter into the continents as we understand them today.\n\nPangaea was not the first supercontinent. From the evidence available, scientists reconstruct that a predecessor, termed Pannotia, formed about 600 Ma, before dividing again some 50 million years later. Another, Rodinia, apparently formed approximately 1,100 Ma and divided 750 Ma.
124708
I like this site for looking at where the continents were at different times as the forces of plate tectonics (continental drift) occured.\nhttp://www.scotese.com/earth.htm\n\n50MYA: http://www.scotese.com/newpage9.htm\n150MYA: http://www.scotese.com/late1.htm\n\nThey even project into the 250MY into the future:\nhttp://www.scotese.com/future2.htm\n\nThey also animate the movement of the plates:\nhttp://www.scotese.com/newpage13.htm
164797
this is a vague queston. But I believe i know what you are asking. Well He already believed that Pangea had formed and broken apart. Evidence from Glacial Striations and rock formations, not to mension an almost perfect mactch of shorelines. I guess it would have more support for his theory. He concluded that the continents were moving. What he could not prove was the mechinism for the movement. it is not actually the continents moving. They are hitching a ride on the techtonic plates.