DNAunion

DNAunion: Here's a short dialogue, in the classical style.

DNAunion: So who's right and who's wrong? Gee, I thought the evolutionist was, until I read something in a popular science periodical.

DNAunion: Not quite as extreme as the Creationist position I presented in the dialogue, but still, doesn't the author's concept of "increased radiation causes increased mutations causes accelerated evolution towards humans" show some naivety in his conception of evolution?

[ September 14, 2002: Message edited by: DNAunion ]</p>

Jesus Tap-Dancin' Christ

First of all there is a lot of "ifs" and "maybes" in that. Second, it's from Discover. Although I love reading it, it isn't exactly accurate all the time. Thirdly, I don't seem to recall there being many stars within 30 light years of us at all--most stars are far further than that from us. Given the supposed rate (way off), there would have to be a large number of blue stars within 30 light years. Unfortunately, given the age of the earth, there are almost NONE in the galaxy. Supernovae do not happen all that often anymore. Blue stars die off in about 10-20 million years. Actually, go off main sequence more like it, but I digress...

pz

Yes. I would think that one of the first things that would be selected for in a population exposed to increased radiation levels would be for better proofreading and repair in replication.

Humans aren't any better at protecting themselves against radiation than are mice or cockroaches or flatworms, and are actually worse in some ways.

Amen-Moses

All the stars within about 60 LY from us are around the same age, in fact we all come from the same hatchery and if there had been any stars large enough to supernova they would have done so before the earliest life we know of on earth came about. (i.e by about 3.9 BYA)

There are well over a hundred stars within that zone btw of which we have only really studied about half. Our limit of any sort of in depth study is limited to about 50LY and within that range we can only detect planets by indirect means that are around Saturn size or greater. In a few decades the large space telescopes planned should be able to detect earth sized planets out to 100L or so, hope I live long enough to see the results.

Amen-Moses

DNAunion

DNAunion: I know, but your average John Smith doesn't read Science or Nature - he reads stuff like Discover.

And this author's implication is, in my view, misleading. And it is, in my opinion, the kind of thing that leads lay people into formulating faulty refutations of evolution along the lines I presented in the CREATIONIST part of the dialogue.

Evolutionists often ask, "Where do these Creationists come up with their wacky ideas?" Well, this could be one example of the kind of thing they base their ideas on, but then when asked where they got it, cannot find it. And it isn't from a Creationist journal - it's from a popular (if anything, anti-Creationist) scientific periodical.

I would like to see some evolutionist from here write a "letter to the editor" to Discover pointing out the naivety of the author's conception of evolution. If I am correct about the author being "in error", it would do a service to the community of evolutionists. Who knows, it might even get printed in the LETTERS section of the next issue.

[ September 14, 2002: Message edited by: DNAunion ]</p>

scigirl

Hmm, interesting point. I think I agree with you here. I also think the media in general does a horrible job with science: they sensationalize new disease discoveries (which gets people's hopes up who are sufferering from the diseases) and they play up the controversies too much. Most science ends up confirming other science, but that doesn't make the front page.

However I'm not exactly sure what to do about this quandry - Discover wants to make money, and scientists want their work to sound interesting and readable, yet leaving out or skimming over the details will inevitably confuse people. Plus, I think many people just don't have the background to fully understand any type of scientific discovery unfortunately.

scigirl

Baloo

Actually, the original creationist point is not as ludicrous as it is made to sound. In an environment conducive to a step-by-step evolution of prokaryotic bacteria into multicellular humans, increased rates of evolution of humans might correlate with higher levels of high-energy radiation. Assuming the original petri dish was large enough (say, the size of earth), humans might have taken 5.0 or 5.5 billion years or so to evolve. However, a burst of radiation every ten million years or so might have "sped up" the process - thus, we are here after a mere 4.0 billion years or so.

However, too much radiation, or too high a frequency of bursts might have done more harm than good (introducing enough mutations to disrupt the stability of entire gene pools and populations and causing mass extinctions). IOW, there is obviously no continuum whereby one could say "with ENOUGH radiation, administered with a high enough frequency, I could turn that 4.0 billion years into 10 or 15 minutes." The true statement would be "I can increase the rate at which populations of organisms adapt to their surroundings by increasing the amount of their radiation exposure; however, there is a level of radiation that will simply kill off the organisms altogether, the result being a complete failure."

This is not mere speculation: in computer simulations of evolution, algorithms are developed wherein rates of reproduction, random mutation, gene transfers, etc., are optimized for the most rapid adaption of "virtual organisms" to their virtual environment, and it quickly becomes evident that there is such a thing as too low or too high a rate of mutation/gene transfer/etc. Similar results are found with the irradiation of fruit flies.

scigirl

Well you not only need genetic mutations to induce evolution, you also need selective pressures. I.e. radiate the bacteria, then stick them in a new or changing environment.

scigirl

pz

Yes, but this is exactly where the claim made in Discover is so wrong. Under the pressure of increased mutagenesis from the environment, organisms will try to compensate...however, evolving into a complex multicellular organism with an elaborate social structure and the capacity to smelt lead and build radiation-proof structures is not the kind of practical, short-term solution that will be favored by evolution. I suspect that a long-term hail of intense radiation from space would give a selective advantage to small organisms with efficient DNA-repair enzymes, that also happen to prefer living under rocks or deep under water.

I'm thinking of bacteria and flatworms, but I suppose that would also apply to runty little trolls.

pz

Another example: the 100 million year old penis story. They sensationalize minor, unimportant stuff. It seems that competent science writers are also in short supply. How many people with an advanced degree in a science and a familiarity with the current literature in a field are willing to use those skills to write for the popular press?

There aren't many.