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Study Provides Compelling Evidence of Single Impact Extinction Theory
ectotherm writes to tell us that a new study at the University of Missouri-Columbia claims to provide compelling evidence that a single meteor impact was the cause of animal extinction 65 million years ago. From the article: "MacLeod and his co-investigators studied sediment recovered from the Demerara Rise in the Atlantic Ocean northeast of South America, about 4,500 km (approximately 2,800 miles) from the impact site on the Yucatan Peninsula. Sites closer to and farther from the impact site have been studied, but few intermediary sites such as this have been explored."
I read this yesterday and have been looking in occasionally to read the comments at the bottom. It looks like there must be some global creationist group that is directing traffic to the story, as every comment makes just that same arguement. I guess the creationist party line is that the "flood" wiped out the dinosaurs. That's a lot of water.
The problem with all these sedimentological studies is that the statistical period between large meteorite impacts and the systematic error in the dating of the sediments (using isotopic geochemistry) in addition to the ambiguity in the fossil record (and the dating errors in those sediments) means that it's guaranteed that you will find a correlation between any mass extinction and a large meteorite impact event.
Around the K-T boundery there is not only the Chixalub impact but a large one in Germany and a couple of others which have been discovered, all within the dating error. Add to this that there's also the Decan Traps flood basalts being errupted, ocean currents changing as the north atlantic starts to open and the amount of flooded continental shelf decreasing hugely and you have several possible smoking guns.
The evidence just isn't there currently to say why most of the dinosaur lineages died out (along with many sea reptiles and other oceanic creatures). In fact there is still a doubt as to when it actually happened and over how long a period. Ammonites, it seems, saw the meteorite coming.. about a million years before it hit.
Agrajag: "Oh no, not again!"
I see a bigger problem with that statement.
If we are to assume God did in fact create the universe and all its laws in such a way to make it look as though it's been around a lot longer than it has, and then gave us the tools of analysis and reason to "discover" these laws and the universe's history, who are we to thumb our noses at him and see through his giant fabrication? I mean, if He went to all this effort to make it look like there were dinosaurs 65 million years ago, carefully placing each photon and atom and what-not, we're pretty big jerks to dismiss all his efforts and say, "Yeah, that was nice with the fossil record and the carbon dating and all, but we know the truth. Good try with all that 'evidence' you made us." Even if you really know the secret truth that the universe has only been around 6500 years, lets not go and put a damper on God's efforts. Just go along with the rest of us when we say things like "Evolution" and "Big Bang"-- it'll make God a lot happier. And you don't want to make God angry.
Natural Selection has EVERYTHING to do with the First Spark of Life".
1. Standard evolutionary theory says that a lower mutation rate, (down to some minimum that is greater than zero) actually increases selection speed. That sounds counter-intuitive, but it is straight from Dawkins and similar sources. One reason here is that mutations are occuring in organisms that are already pretty close to perfectly adapted to their environments or they'd be dead. The few mutations that are improvements are generally small improvements, that take generations of testing to prosper. A high enough mutation rate, and a new mutation overwrites the last one before the first had time to be tested. To see this a little more clearly, just imagine a mutation that makes an annual type plant a little better able to resist drought. If droughts only happen in that area about every 20 years, the mutation only helps a carrier survive every twenty generations or so. There are several other arguements for this point, which can be found in the Dawkin's The Selfish Gene or The Blind Watchmaker, or in a typical college textbook on the subject.
(Anyone who doubts this is standard theory is welcome to write somebody such as Dr. Dawkins and ask, or for God's sakes read a little. Usually when I get this far, someone insists this isn't the standard theory of evolution at all, and proposes some kind of Lysenkoism as the standard instead. I am very sick and tired of proposing this and having people who think evolution means the X-men try to prove I'm wrong.).
2. Modern organisms use DNA, with both advanced error correction and mutation reduction. One form of correction is sexual reproduction, by using a second copy of most genes. One form of reduction is putting the DNA in a central nucleus where it is less exposed to chemical mutagens.
3. Fully modern DNA in sexual organisms has been around for at least 700 Million years (see Dr. Simon Conway Morris's estimates for the age of the earliest Ediacaran fauna. If he's not THE greatest still living expert on this, he's at least number 2.).
4. Less modern DNA, but still with error protection in the form of nucleated cells, has been inside the oldest fossil eukarotes since, at the absolute very least, 2.1 Billion years ago (again Morris's timetable). That's also about half the age of the Earth (4.2 Billion years).
5. Really primative DNA with no correction or protection, has been found, again at the very least, as far back as the first stromatolites (2.9 billion years). Most paleontologists (admittedly not all), point to earlier fossils, as early as 3.5 billion years old, for the first DNA based organisms.
6. DNA is believed to have developed from RNA. RNA is still used by most life as a messenger chemical, but is only found as a heredity chemical in some very primative viruses. The error rates for RNA are well known, and indicate evolution must have been proceeding very slowly, even compared to the most primative DNA based life. The living record agrees with this, as do extensive tests comparing generalized eukarotes with all surviving types of non-eukarotes. While it's not as universally agreed by biologists as the earlier points, it's still generally agreed that RNA did predate DNA. You can find a few recognized biologists who don't support this last point, but they are a distinct minority, under 5%.
7. This means, we have counted back to within about 700 million years of the time Earth formed, just for the three stages of DNA based life. That's about 84% of all the time we have to explain life. The RNA dominant period, when evolution was much slower, has to fit into that last 16%. Whatever came before RNA has to fit into what's left after RNA gets its share, and so on.
8. By the standard theory's best guess, there are at least a dozen stages, each with more primative molecules involved, going back to the beginnings of life. The earliest ones might have been non-living clay-like substances, where natural selection operated only
Who is John Cabal?
Can God create a "square circle" or a "triangle with four sides"? The fallacy is that of assuming that the answer of canCreate(x) should be either true or false. For some values of x, you just get an ArgumentException, which is really neither ;)
P.S. And no, I'm not a Christian.