posted
I've done a couple of genetics papers in my time but nothing super complex and that was a little while a go, so I'm having trouble getting my head around something and I was wondering if anyone could help
I've come across an argument from someone that believes in mutations and adaptation but not evolution, who says that(to put it simply) - No new genes are added through mutation and adaptation. Any changes involve sorting or loss of genetic information, not an increase in genetic information. A gain of genetic information is what would be required for microbe to human evolution to be credible.
It's the loss of information part that I'm struggling with - how does adaptation cause loss of information? If you had say a sequence of DNA that was duplicated and then down the track a point mutation occurred which produced a desirable phenotype - is that not an increase in genetic information?
And the other thing is that gene loss is probably a contributor to evolution according to the "Less is more" theory.
But then it was also mentioned that genetics are degrading, that the pool of genetic potential is decreasing, so species are less able to adapt to changes in our environment.
Not quite sure what was meant by "genetics are degrading" but are the last two parts of that sentence true?
Sorry if these questions are rather dense - I'm feeling a little dense at the moment Posts: 315 | Registered: Jun 2002
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quote:No new genes are added through mutation and adaptation. Any changes involve sorting or loss of genetic information, not an increase in genetic information.
Gene duplication is well-documented and further mutation can produce novel genes with new functions:
quote:The duplication of a gene results in an additional copy that is free from selective pressure. This allows the new copy of the gene to mutate without deleterious consequence to the organism. This freedom from consequences allows for the mutation of novel genes that could potentially increase the fitness of the organism or code for a new function. An example of this is the conjectured mutation of a duplicated protease gene in a family of ice fish into a gene coding for an antifreeze glycoprotein.
When faced with the "no new information from mutation" argument, I usually just ask for the method by which they are measuring information. For any meaningful definition of information it can be shown that mutations can produce more information.
Posts: 3275 | Registered: May 2007
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quote:Originally posted by stacey: It's the loss of information part that I'm struggling with - how does adaptation cause loss of information? If you had say a sequence of DNA that was duplicated and then down the track a point mutation occurred which produced a desirable phenotype - is that not an increase in genetic information?
Mine are the words of a scientific layman, so do remember I can be wrong, or it's too simplified.
/disclaimer
Yeah, the reason you're struggling with that idea is because it's blatantly wrong. I'd be surprised if the person you spoke to even knew what duplication and point mutations even are.
You were talking to someone who actually doesn't know what they're talking about. That mangling of information theory has become pretty popular lately, but it has no basis in the actual reality.
We've seen the creation of novel traits in real time. I can think of an example off the top of my head and could show you, if you'd like.
Posts: 1577 | Registered: Sep 2005
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posted
Yes. New genes occur all the time. We observe them all the time. There's absolutely nothing unusual about new genes appearing.
Thus, anyone who bases their argument on "no new genes are possible" is at best ignorant, and more likely at least willfully ignorant, refusing to believe new genes can occur (despite them being observed, repeatedly).
The problems with the 'genetic information' argument have been well covered -- I've never seen anyone promote that who could actually define how the genetic code translated to information.
Posts: 15770 | Registered: Dec 2001
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She studied Biomedical Science, majoring in human reproduction and development - which is probably a bit cooler that my Bachelor of Science in Animal Science Which is why I was doubting my original feeling that the picture they were painting wasn't correct... I think my problem though is I learnt just enough to know I don't know very much
Yeah, I'd be interested to know some examples of novel traits 0Megabyte - Just for future reference Posts: 315 | Registered: Jun 2002
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posted
Here is a paper that nicely describes both the mechanisms by which new genes are created and some examples that have been observed.
Posts: 3275 | Registered: May 2007
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posted
Nobody should be given a degree, be it only in Creative Basketweaving, who cannot define 'information' in such a way that it's actually measurable.
Posts: 10645 | Registered: Jul 2004
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