Sorry, that should be “just as easily as you see resistance evolving in the WILD.” I already said lab. 
DNA mutates all the time. Why do you think we get cancer? And 0.000001% of the time (for example) it will mutate in a non-harmful way.
Sorry, forgot to mention - meiosis is imperfect. Mutation comes from all of the above: random mutation of base pairs, reduplication, imperfect meosis and crossing over.
Malacadra: The conceptual hurdle your facing is that your assuming a non-self selecting process. Lets churn some numbers:
Assume we have a Population P with 1,000,100 members, the average generation time is 10 years. Of these, 1,000,000 have no mutation and, their population numbers dont change. The additional 100 are conveyed with a benificial mutation that gives them an extra 0.1% survival benifit.
At T0, we get 100 with mutation, 1,000,000 without.
At T100, we get 101 with mutation,
At T500, we 105 with mutation.
At T1000, we get 110.
At T5000, 165.
T10,000, 2717
T50,000, 14,804
T100,000, we get 2,191,668 with the mutation, 1,000,000 without.
After 100,000 years, a relative eye blink in evolutionary terms, the mutated ones dominate the non-mutated ones 2 to 1. Even very tiny evolutionary benifits spread through a population relatively quickly.
It should also be noted that sex basically speeds up the process of adaptation. In short, it is an evolution in the way life evolves. Meta-evolution! In fact, a great paper testing this exact idea recently came out, showing that sexual reproduction in yeast is far better capable of adapting to harsh conditions than asexual reproduction. Discussed here:
http://pharyngula.org/index/weblog/comments/why_sex/#continue
Not to mention that variations don’t arise one at a time, but many different sorts all over the genome happening all the time.
Well, but suppose we try this on for size:
The bacterium’s ability to reprogram itself to combat a bio-threat does not appear ex nihilo as a result of random errors in copying the genetic code from one generation to the next. Rather, it exists in potentia in the genetic code of the entire species. Whether it is expressed in any given instance of the organism is probably beyond our ability to measure. Any given bacterium will produce descendants that, in some instances, are better equipped to survive one antibiotic or another. Why not? But those later generations do not in fact possess any more genetic information than their ancestor did. Hypothesis If you take a sample of bacteria from any point in the history of the species, each sample will be approximately as fitted to survive, in as wide a range of environments, as any other. (This strikes me as extremely testable.) Assertion: We have yet to see an accumulation of such changes result in the emergence of a species.
Breeding dogs does not count as creating species either. True, by artificially selective breeding and equally artificial efforts to keep the resulting specimens alive, you can emphasise the effects of recessive traits and so produce dogs that are abnormally large, small, hairy, smooth, wrinkly, bandy-legged, and so on, and so on. But at no point have you eliminated the characteristics of the original species; you can emphasise scent at the expense of sight, say, or speed at the expense of strength, but the end result will never have six legs, meow, fly, or breathe water; and if you took, say, 16 pedigree dogs and 16 pedigree bitches all of different breeds and bred them all back together, their great-great-great-grandpups would not be noticeably different from a wild cur.
Concerning cancer: I’m not disputing that damage to the DNA coding can mutate its owner in harmful ways (there is no doubt that cancer is harmful, even from the selfish point of view of the cell that is over-reproducing itself; by killing the host organism, it is ruining its own chances of survival). I can very easily scratch my favourite vinyl LP of Beethoven’s Fifth and produce a less harmonious piece of music. What I can’t do is dip it into a bucket of sand, fish it out, play the resulting scratched record and expect it to sound better, or even anything like as good.
(Btw, this has turned damned civil for a Pit thread, hasn’t it?)
On the contrary: it IS within our ability to measure. Bacteria do not gain resistance simply by bringing a tool out of storage the way you imply. Instead, single bacteria rapidly diversify: the children all look less and less like their communal parent over time. It isn’t simply a function of different traits in the starting genome coming out. They are real honest to goodness differences in the actual genetic code.
Nice try. But in the face of the fact that we can sequence the genes directly and see what changes, no dice. The number of papers in which mutations are observed that increase function in some way in bacteria are almost too many to count, and the phenomenon so routine that such studies barely ever warrant a mention in journals on evolution. The easiest sorts of these experiments are to break some function by removing a crucial piece, and then seeing if the bacteria can “re-evolve” it. Not only can they, but they more often than not surprise by not re-evolving the same solution, but hitting upon completely different solutions than before, or even evolving entirely new traits unrelated to the deleted function but related to the impact of the changes made.
And of course, in bacteria, the problem with “species” is laid bare. For most bacteria, asexual is the only sexual they use. So the criterion of “interbreeding” is out. In bacteria, accumulation of genetic difference is the ONLY thing that can define a species.
No one said it did, though it should be noted that dogs are another reason why “species” is really not the meaningful and objective category people assume. There is far more genetic variation between breeds of dogs than there is between all sorts of legitimate species, simply because dogs have been kept closer in regards to their actual reproductive genetics than they have in other features.
Sorry, no dice here either. Many of the genes for a shitzu are just not found in Great Danes. And the genes for either are not in modern wolves descended from their common ancestors.
And again, if your theory that all observed change was merely existing diversity playing itself out, then we would have run out of genetic diversity a long long time ago, since there would only ever be a fintite amount to play with. Instead, there seems to be no end to it. And this mystery is no surprise when we look down at the gene level and see variations popping up left and right.
You also seem pretty off with your belief that something like a longer leg is a fundamentally different sort of change than growing a new leg. But depending on how the genes shake out, the latter can often be a much smaller genetic change than the former (for instance, simply accidentally duplicating a hox gene that basically tells other proteins to “build leg here” vs. the complex balance of altering the size and structure of something as it lengthens or shortens)
The point of the dogs is not to demonstrate speciation (of which we have much clearer examples of) but rather to demonstrate that the traits we select from had to have come from somewhere. Genetic studies allow us to tell exactly where. Furthermore, dogs also demonstrate the issue noted by Darwin that there seems to be no good line on which to draw between distinctions like species, sub-species, breed, race, individuals, and so on.
Scientists, as Darwin noted, spend endless time arguing over whether something is a different species of just a sub-species, or a different genus vs. just a different species. This is exactly the sort of problem that evolution would predict that we should have as constantly as we have it. We’ve come up with a sort of ad hoc and reasonably useful definition of speices in the “interbreeding” criterion, but as I noted with dogs, it rarely seems to match up well with actual genetic difference, and there are even further wrinkles. For instance, ring species confound classification. Two birds in the same area don’t interbreed, but one does breed with its near relatives to the west, while the other does breed with its similar neighbors to the east. Continue this pattern around the globe in both directions, and the two lines of interbreeding end up meeting each other seamlessly!
Or consider that the criterion of interbreeding is largely still and artificial one, as it has to be couched in all sorts of caveats about breeding in MOST cases, and only in the wild. As species separate, there are often a range of somewhat, though less and less viable potential matchups. Horses and donkeys can mate, for instance, but the result is the sterile mule. Tigers and lions can mate, and the result is a Liger that is not always sterile. Or wolphins. The more genetically distant species are, the less likely any possible offsping will be able to breed (and with which parent species is another issue), if there are any offspring at all, but the mere fact that nature does not seem in practice to much respect strict species boundaries in the first place is yet another reason to understand “species” as largely a tool that helps us understand kind groups and populations and makes classification easier, rather than some absolute objective fact of nature.
And, as I noted, the exact same genetic ancestry studies that give us lines that comport with recorded history of particular pedigrees can be done on dogs vs. wolves, wolves vs. bears, and so on. The practice, proven to deliver accurate results in the small scale, seems to work just the same in the large scale (which itself comports with fossil and geographic evidence). That would be a very surprising result for anyone claiming that common descent wasn’t a fact, and pretty darn hard to explain away by any other reasoning.
Excellent! And this, I submit, is the creationism vs. debate that should be going on in the schools, rather than simply maligning one side or the other for believing whatever their particular set of men in funny clothes tell them.
Thanks for participating, everyone. I’ve enjoyed it immensely.
The Doppler effect is a THEORY, not a fact. Don’t teach it in MY school! :mad:
Not on your life. If creationism had a side, then we might have something to teach. But what, exactly IS creationisms’ side? What is the positive theory? What is the evidence? What are the well-informed critiques of evolution? The fact is, there aren’t any. As such, we teaching the creationism vs evolution debate in science class would be as ridiculous as teaching holocuast denial in history or astrology in astronomy. Not to mention: which version of creationism are we supposed to teach?
Kids in high school have enough to get through in biology without also spending tons of time not learning about legitimate, honest science.
I take your point, but I don’t entirely agree. After all, I like to think I just put up a case that stood up to at least a few minutes of casual criticism, even though this isn’t my own point of view nor one that I’ve researched enough to be conversant with all the arguments. (And we haven’t even touched on “irreducible complexity”.)
I like astronomy myself. I’d rather engage a classful of kids with “Advance some arguments as to why astrology might hold water, and then examine what is wrong with the arguments” than “Astrology is bunk. Let’s get on with the lesson”- although the sentiment does closely mirror my own point of view. It encourages critical thinking and builds debating skills. (Mine suck, but the Dope is an education.)
Ciao!
With all due respect, posting a few uninformed arguments on a messageboard is not making a case for anything.
There are plenty of ways to encourage critical thinking without trying to sneak religious agendas into the classroom. Heck, the normal process of science ALREADY is a debate. But it’s a deabte that is conducted on evidence and research rather than out there political and religious conspiracy-theories. Half the reason I don’t tihnk creationism is appropriate in the classroom is that it could very easily end up disparaging people’s religious beliefs.
There are far more interesting mysteries and debates to be had WITHIN a field like astronomy without getting into all the crackpot theories out there.
'k. Considering myself duly slapped, and exiting the thread, having nothing more of substance to add.
Mmf.
I learned about creationism in science class - along with phlogiston and spontaneous generation. I think it is important to cover the history of science, and to not treat those who came before as fools. It is good for a student to appreciate why they believed in these things, and the evidence that caused science to be where it is today. It has been a long time since I’ve been in school, but it seems that science is taught as if it came down out of the sky, not as a process.
Maybe in that way we can show how creationism is a step back two centuries without getting into religion or today’s false controversies.
The problem is that if we present something like young earth creationism in the classroom, and then go on to show why it’s all wrong, as per the evidence, that’s pretty darn insulting to people’s beliefs. I can’t see how that would go well. It’s always simpler and more philosophically honest to just say: science is a method, and this is what we get when we apply that method.