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Earliest Bird Had Feet Like Dinosaur
aychamo writes "A 150-million-year-old fossil of Archaeopteryx, the earliest known bird, may put to rest any scientific doubt that theropods gave rise to modern birds. From the article: '[A new fossil] presents important new details of the skull morphology [shape and function] of the earliest known bird, showing also that the skull of Archaeopteryx is much more similar to that of nonavian theropod dinosaurs than previously thought.' In the new fossil, the foot looks more like that of the four-toed foot of Velociraptor and its other nonwinged theropod relatives. The specimen also clearly lacks a reversed toe. Because Archaeopteryx lacked this stabilizing toe, it almost certainly did not habitually perch in trees. This leads scientists to believe that it was a land based predator."
please don't call ID a scientific theory, since it meets none of the criteria. It is not accepted by anyone except fundamentalists. Really, even the catholic church agrees that ID is not science, and that evolution happens. It must be difficult to be that backwards.
While the majority of mutations are indeed bad, there are plenty that are relatively harmless.
For example, have you ever seen a cat (or other creature) with extra toes? That's an example of a minor mutation which, although it does no good that I know of, also does no harm to the creature. There are plenty of others like this as well, as well as mutations that cause only a small amount of harm but provide the mutated creature with some sort of protection against death or disease. In this latter category you get things like sickle cell anemia, which is incredibly common in parts of Africa. This is an unpleasant condition to have if you get the homozygous form, but in the heterozygous form, it increases your chances of surviving malaria, so many of the people who don't have it die, and the mutated gene gets passed on. Incidentally, this mutation occurs in other populations, but to my knowledge, it is only beneficial in places where malaria is or was common, so it is only prevalent in those locations.
Another form of beneficial mutation occurs in bacteria all the time. I assume you've heard of drug resistant bacteria -- do you know how that happens? Basically, if an antibiotic is applied to a colony of millions of bacteria and even one just happens to have randomly mutated in a way that stops the antibiotic, every bacterium will die except for the resistant one. Given how fast bacteria reproduce, it doesn't take long before even a statistically improbable mutation is pretty much guaranteed to happen... and usually, it does. Next thing you know, you have a whole colony of resistant bacteria because any who lack that mutation just die.
Here's another example of beneficial mutations involving bacteria: when scientists test potential mutagens, one way of doing it is to genetically engineer a batch of bacteria that lacks the ability to produce some essential nutrient. Such bacteria can only be grown on a special medium (one which contains the nutrient that they cannot produce) and will immediately die in any other environment. These genetically engineered bacteria are then brought into contact with the potential mutagen, and the colonies are transferred to a normal growth medium. Then the scientists count the number of colonies that survive. They're seeing whether the potential mutagen has the ability to reverse their genetic engineering... and if the tested compound -is- a mutagen, they will almost certainly see bacteria growing happily in their new home.
So yes, it -is- possible to have a mutation specifically where and when you need it because if it doesn't occur, the population may well die out. We only see the lucky ones who were able to mutate in the "right" way... the ones who didn't are dead.
Here's a brief technical look at the theory by the University of California - Berkeley's
Museum of Paleontology : http://www.ucmp.berkeley.edu/diapsids/avians.html
Of interest are twenty proposed characteristics "the first birds shared [...] with
many coelurosaurian dinosaurs." Take a look and see what you think.
-Shawn
You see, a theory is created by observing natural phenomena and evidence, forming a hypothesis as to why it happens or acts that way, testing it, then letting the scientific community corroborate your tests, and continue testing whenever new evidence comes along to refine or disprove it.
On the other hand, ID was created by replacing the word 'god' with the term 'intelligent designer'
Evolution has a great deal of evidence supporting it, from fossil records, to DNA similarities in similar species, to the fact that farmers or scientists can selectively breed plants, fruit flies, or anything with a short period between generations to selectively breed certain traits.
On the other hand, creationism has a series of books that are thousands of years old, and some rhetoric about fossil records being put there to trick us.
perhaps you'd like to take a look at the wikipedia pages on scientific theory or scientific method to find out what a theory actually consists of.
Well, the Dodo was well suited for its environment BEFORE humans came into it. That said, before someone throws up "Well, chickens aren't perfect either, so there!". Dodos were tasty for humans at that time (the islands they lived on were on shipping routes) and sailors would collect huge piles of eggs to eat on their voyages. See what they did? Absolutely no care for long-term survival - the sailors ate BOTH the birds AND the eggs, in massive numbers. No population's going to survive that. I postulate that if chickens were in the same situation as the Dodo, they'd just have gone extinct as well. There just aren't any wild variants of chickens, are there? Humans have hunted and domesticated chickens for so long, the wild variants have gone extinct, and only the domesticated ones exist.
You take the data from a scientific experiment and plot it out on a graph and then derive a curve from those plotted points. Then you try the experiment again and again and again. Eventually, you should be able to predict where on that curve the data will fall.
You don't need to determine every point on that curve. In fact, it is impossible to plot every point on that curve; there will always be gaps.
We have hundreds of millions of data points supporting evolution. This latest discovery, in an analogous way, fits the curve. That it only "plugs one hole" or fills one gap is absolutely irrelevant.
In any case, you're wrong: some mutations are beneficial; this is not controversial in any way, even among "creation scientists". We have seen it happen on shorter time-scales (the Daphnia of Lake Constance, and so forth). If your main objection is that we haven't seen it on a "macroevolutionary" scale, I have two answers for you. First, the article in question describes such an occurrence; we don't have to witness it happening for it to fit the curve. Second, the "macro/micro-evolution" canard is a false dichotomy.
Lastly, ID is not growing as an accepted scientific theory, because it is not a scientific theory. It is not falsifiable; therefore it is not scientific. Period.
www.kitchengeek.com -- Nosh for
I refer you to this primer on how the probability for spontaneous generation of of life only appears to be so high as to be impossible, and why the "airplane parts in a hurricans" analogy is just plain ridiculous.
www.kitchengeek.com -- Nosh for
What it is saying is that the archeopterix has features that are VERY similar to a dinosaur's, yet very similar to a bird as well. Therefore this is the ever-so-elusive "transitional species" that creationists have been asking for (others exist, but this is one that they would almost always point to). Though it was already essentially proven that this was indeed a transitional species, this provides even MORE evidence and is therefore the proverbial "icing on the cake."
To answer your question about birds and archaeopteryxes (spelling?) coexisting, I would ask you the following: how come we haven't found ANY fossils of modern birds? If they were to have coexisted, there should be SOME fossils of modern birds that could be dated to that period. All modern birds, however, have been found to be from more recent times and, as time goes on, their features depart linearly from that of the archaeopteryx. So, while it may be possible that they existed at the same time, such a situation would mean that ALL of the scientific evidence that we currently have would be wrong and that the pattern of developement would be a total coincidence. That, quite frankly, I have a hard time believing.
Also, note that IANAB (I am not a biologist). Please correct me if I have facts incorrect.
Ride the skies
I invite you to read this explanation of probability in abiogenetic theory. It pops every one of your bubbles.
www.kitchengeek.com -- Nosh for