Neat recent information on genetics, mutations, and evolution.
http://seattlepi.nwsource.com/nation...42_tiny23.html
Tiny organisms (rotifers) that have no males... yet have 340 species. Beautiful example of diversity without sexual selection... must be another mechanism. Could it be..... mmmmmmmutations?
But, according to some flawed mathematical models, pure random chance of mutations would lead to unviable organisms too often to allow a species to perpetuate.
Enter Scientific American, Mar 2004 article on error correction in codons. Very very cool stuff. Essentially, roughly 30% of all random mutations *on active codons* result in *no change* to the organism. Another ~30% or so cause one amino acid to be replaced with a similar amino acid that often will perform the same function, in a slightly different manner. Only the remainder (<40%) have any chance of creating a serious change. *Then* you get into the nature of nonviable vs. improved. Very neat.
So a random mutation has to a) occur on a sensitive stretch, b) hit the first or second element of a codon to have any effect, c) hit the first one alone to cause a serious change.
Add in gene swapping, etc, and suddenly the 'randomness' drops considerably. Self-organizing systems. Gotta love 'em.
Tiny organisms (rotifers) that have no males... yet have 340 species. Beautiful example of diversity without sexual selection... must be another mechanism. Could it be..... mmmmmmmutations?
But, according to some flawed mathematical models, pure random chance of mutations would lead to unviable organisms too often to allow a species to perpetuate.
Enter Scientific American, Mar 2004 article on error correction in codons. Very very cool stuff. Essentially, roughly 30% of all random mutations *on active codons* result in *no change* to the organism. Another ~30% or so cause one amino acid to be replaced with a similar amino acid that often will perform the same function, in a slightly different manner. Only the remainder (<40%) have any chance of creating a serious change. *Then* you get into the nature of nonviable vs. improved. Very neat.
So a random mutation has to a) occur on a sensitive stretch, b) hit the first or second element of a codon to have any effect, c) hit the first one alone to cause a serious change.
Add in gene swapping, etc, and suddenly the 'randomness' drops considerably. Self-organizing systems. Gotta love 'em.
Comments
Originally posted by Kickaha
{Software engineering, software design, programming language} theory and analysis tools. Yours?
Oh, I was only asking because you seem very familliar with several fields of science. Right now I work (temporarily) as a postman. But I'm going back to studying in the fall.
Originally posted by KANE
I hope I didn't kill this thread with my off topic question.
Like it had a life to begin with.
Naw, I just read a lot. Sometimes more than I should. (Stupid dissertation and paper deadlines getting in the way of fun reading...)
Originally posted by Kickaha
(Stupid dissertation and paper deadlines getting in the way of fun reading...)
Huh? I thought that's what dissertations were for? How else could we justify procrastination?
Cool stuff. I like Scientific American. I should get a subscription.
Originally posted by Kickaha
Like it had a life to begin with.
Naw, I just read a lot. Sometimes more than I should. (Stupid dissertation and paper deadlines getting in the way of fun reading...)
You read fast and you type fast? That's a winning combination.
Originally posted by torifile
Huh? I thought that's what dissertations were for? How else could we justify procrastination?
Hey, I've been here 6 years, I need the fudge out.
Cool stuff. I like Scientific American. I should get a subscription.
Yeah, between that, AAAS Science coming every week, and all my technical journals, I barely have time to read my comics every week! I mean jeez!
Originally posted by KANE
You read fast and you type fast? That's a winning combination.
Wanna tell my committee that?
What the heck were we talking about again?
Thanks for the link, Kick, I even posted it to my family page to see if I can get the old folks stirred up in a fiesty evolution debate.
Good stuff.
Originally posted by Stoo
Are there other "large" animals that reproduce asexually or are these the only ones ?
I believe these are the largest known, and the most diverse. Very cool.
When dealing with parthenogenesis, mutation is the most likely genetic drift factor (swapping, splicing and shuffling are also in there), and these little suckers do so successfully. Keen.
This is not proof of evolution.
It *is* however, showing that the pseudo-mathematical models that proclaim to show that evolution is 'scientifically impossible' (when of course they mean 'statistically improbable') are highly, highly flawed.
The mechanisms are not truly random, and they never were... the models fail to take that into account. (Mostly because if they did, they'd suddenly be a lot less... er... pseudo-compelling.)
The rotifers are evidence that point towards a stronger claim that mutation factors *can* lead to diversification in a meaningful way, all on their own.
(Of course, some will claim that they're 100% proof of Creationism, since how could they have *possibly* evolved when mutation-based evolution has been 'proven' to be wrong, and 'scientifically impossible', so I'll just get that out in the open right now as an alternate view.)
I think if I wasn't so into music, I would consider anthropology as a probable field of concentrated study.
Personally, I never once bought any of that god stuff when it comes to creation, I just think that's a load of unreal...ness. Particularly when evolution makes so much more sense, at least to me.
I often get in discussions with my roommate, he's not a creationist, but he doesn't seem to get evolution either. Like he understands it, but he doesn't understand that it's without design.
Recommended reading, for anyone interested in this stuff, Richard dawkins, 'the blind watchmaker' in particular, is great.
Originally posted by Kickaha
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Enter Scientific American, Mar 2004 article on error correction in codons. Very very cool stuff. Essentially, roughly 30% of all random mutations *on active codons* result in *no change* to the organism. Another ~30% or so cause one amino acid to be replaced with a similar amino acid that often will perform the same function, in a slightly different manner. Only the remainder (<40%) have any chance of creating a serious change. *Then* you get into the nature of nonviable vs. improved. Very neat.
Not to burst your bubble, but this is well-established knowledge
Basically, three codons form one triplet which encodes one amino-acid. So, like 8 bit form one byte, we are talking about a code with a word-length of 3. The least significant bits (also called wobble codons) can be mutated quite easily without causing too much disturbance. However, the same is not true for the two other codons.
Basically, the point why simple statistical calculations about the likelyhood of live fail is because they only take into account mutation and disregard selection. After one successful mutation has been established, it serves as the basis for future improvement. So, the millions of mutations that led to the emergence of higher animals are not independent in a statistical sense.